tag:blogger.com,1999:blog-14012928180621531232024-02-20T18:20:06.343-08:00Java ProseFollow my path of Java knowledge through example scripts, applications, and articles.Unknownnoreply@blogger.comBlogger21125tag:blogger.com,1999:blog-1401292818062153123.post-27749908684645848182009-10-21T15:22:00.000-07:002009-10-21T15:22:06.779-07:00JSP - gather, process, store, and use session variables<pre><span class="ST0"><!--</span>
<span class="ST0">just a typical html form</span>
<span class="ST0">This is the "theform.jsp" page</span>
<span class="ST0">--></span>
<%@<span class="ST1">page</span> <span class="attribute-name">contentType</span>=<span class="attribute-value">"text/html"</span> <span class="attribute-name">pageEncoding</span>=<span class="attribute-value">"UTF-8"</span>%>
<span class="ST2"><!DOCTYPE</span> <span class="ST2">HTML</span> <span class="ST2">PUBLIC</span> <span class="ST2">"-//W3C//DTD</span> <span class="ST2">HTML</span> <span class="ST2">4.01</span> <span class="ST2">Transitional//EN"</span>
<span class="ST2">"http://www.w3.org/TR/html4/loose.dtd"</span><span class="ST2">></span>
<span class="ST1"><</span><span class="ST1">html</span><span class="ST1">></span>
<span class="ST1"><</span><span class="ST1">head</span><span class="ST1">></span><span class="ST1"><</span><span class="ST1">title</span><span class="ST1">></span>enter form data<span class="ST1"></</span><span class="ST1">title</span><span class="ST1">></span><span class="ST1"></</span><span class="ST1">head</span><span class="ST1">></span>
<span class="ST1"><</span><span class="ST1">body</span><span class="ST1">></span>
<span class="ST1"><</span><span class="ST1">form</span> <span class="ST3">method</span><span class="ST3">=</span><span class="attribute-value">"post"</span> <span class="ST3">action</span><span class="ST3">=</span><span class="attribute-value">"formSaver.jsp"</span><span class="ST1">></span>
Username: <span class="ST1"><</span><span class="ST1">input</span> <span class="ST3">type</span><span class="ST3">=</span><span class="attribute-value">"text"</span> <span class="ST3">name</span><span class="ST3">=</span><span class="attribute-value">"username"</span> <span class="ST1">/></span><span class="ST1"><</span><span class="ST1">br</span> <span class="ST1">/></span>
Cool Factor: <span class="ST1"><</span><span class="ST1">input</span> <span class="ST3">type</span><span class="ST3">=</span><span class="attribute-value">"text"</span> <span class="ST3">name</span><span class="ST3">=</span><span class="attribute-value">"coolfactor"</span> <span class="ST1">/></span><span class="ST1"><</span><span class="ST1">br</span> <span class="ST1">/></span>
<span class="ST1"><</span><span class="ST1">input</span> <span class="ST3">type</span><span class="ST3">=</span><span class="attribute-value">"submit"</span> <span class="ST3">value</span><span class="ST3">=</span><span class="attribute-value">"submit"</span> <span class="ST1">/></span>
<span class="ST1"></</span><span class="ST1">form</span><span class="ST1">></span>
<span class="ST1"></</span><span class="ST1">body</span><span class="ST1">></span>
<span class="ST1"></</span><span class="ST1">html</span><span class="ST1">></span>
<span class="ST0"><!--</span>
<span class="ST0"> this page grabs the form data and</span>
<span class="ST0"> and (with the help of the UserFormBean class)</span>
<span class="ST0"> places the items as session data.</span>
<span class="ST0">--></span>
<span class="ST0"><!-- the useBean taq is where this jsp page loops in the real classes --></span>
<<span class="ST1">jsp:useBean</span> <span class="attribute-name">id</span>=<span class="attribute-value">"userform"</span> <span class="attribute-name">class</span>=<span class="attribute-value">"userform.UserFormBean"</span> <span class="attribute-name">scope</span>=<span class="attribute-value">"session"</span>/>
<span class="ST0"><!-- the setProperty tag sends * (all) the property data to userform --></span>
<<span class="ST1">jsp:setProperty</span> <span class="attribute-name">name</span>=<span class="attribute-value">"userform"</span> <span class="attribute-name">property</span>=<span class="attribute-value">"*"</span>/>
<span class="ST1"><</span><span class="ST1">html</span><span class="ST1">></span>
<span class="ST1"><</span><span class="ST1">head</span><span class="ST1">></span><span class="ST1"><</span><span class="ST1">title</span><span class="ST1">></span>Form Saver<span class="ST1"></</span><span class="ST1">title</span><span class="ST1">></span><span class="ST1"></</span><span class="ST1">head</span><span class="ST1">></span>
<span class="ST1"><</span><span class="ST1">body</span><span class="ST1">></span>
<span class="ST1"><</span><span class="ST1">p</span><span class="ST1">></span>Your data has been placed in a session!<span class="ST1"></</span><span class="ST1">p</span><span class="ST1">></span>
<span class="ST1"><</span><span class="ST1">p</span><span class="ST1">></span>Try visiting this <span class="ST1"><</span><span class="ST1">a</span> <span class="ST3">href</span><span class="ST3">=</span><span class="attribute-value">"unrelatedPage.jsp"</span><span class="ST1">></span>unrelated page!<span class="ST1"></</span><span class="ST1">a</span><span class="ST1">></span><span class="ST1"></</span><span class="ST1">p</span><span class="ST1">></span>
<span class="ST1"></</span><span class="ST1">body</span><span class="ST1">></span>
<span class="ST1"></</span><span class="ST1">html</span><span class="ST1">></span>
<span class="ST0"><!-- this is the unrelated page that will pull</span>
<span class="ST0"> and display the session data --></span>
<span class="ST0"><!-- this loops in the session data we'll utilize --></span>
<<span class="ST1">jsp:useBean</span> <span class="attribute-name">id</span>=<span class="attribute-value">"userform"</span> <span class="attribute-name">class</span>=<span class="attribute-value">"userform.UserFormBean"</span> <span class="attribute-name">scope</span>=<span class="attribute-value">"session"</span>/>
<%@<span class="ST1">page</span> <span class="attribute-name">contentType</span>=<span class="attribute-value">"text/html"</span> <span class="attribute-name">pageEncoding</span>=<span class="attribute-value">"UTF-8"</span>%>
<span class="ST2"><!DOCTYPE</span> <span class="ST2">HTML</span> <span class="ST2">PUBLIC</span> <span class="ST2">"-//W3C//DTD</span> <span class="ST2">HTML</span> <span class="ST2">4.01</span> <span class="ST2">Transitional//EN"</span>
<span class="ST2">"http://www.w3.org/TR/html4/loose.dtd"</span><span class="ST2">></span>
<span class="ST1"><</span><span class="ST1">html</span><span class="ST1">></span>
<span class="ST1"><</span><span class="ST1">head</span><span class="ST1">></span><span class="ST1"><</span><span class="ST1">title</span><span class="ST1">></span>an unrelated page<span class="ST1"></</span><span class="ST1">title</span><span class="ST1">></span><span class="ST1"></</span><span class="ST1">head</span><span class="ST1">></span>
<span class="ST1"><</span><span class="ST1">body</span><span class="ST1">></span>
<span class="scriptlet-delimiter"><%=</span> userform.getUsername() <span class="scriptlet-delimiter">%></span> | <span class="scriptlet-delimiter"><%=</span> userform.getCoolfactor() <span class="scriptlet-delimiter">%></span>
<span class="ST1"></</span><span class="ST1">body</span><span class="ST1">></span>
<span class="ST1"></</span><span class="ST1">html</span><span class="ST1">></span>
</pre><pre><span class="comment">/*</span>
<span class="comment"> * This is the actual java class "UserFormBean"</span>
<span class="comment"> * that processes and stores the data.</span>
<span class="comment"> *</span>
<span class="comment"> * Notice that the set methods use</span>
<span class="comment"> * the same names as the form name data!</span>
<span class="comment"> *</span>
<span class="comment"> * */</span>
<span class="keyword-directive">package</span> userform;
<span class="keyword-directive">public</span> <span class="keyword-directive">class</span> UserFormBean {
String username;
String coolfactor;
<span class="keyword-directive">public</span> <span class="keyword-directive">void</span> setUsername(String value) {
username = value;
}
<span class="keyword-directive">public</span> <span class="keyword-directive">void</span> setCoolfactor(String value) {
coolfactor = value;
}
<span class="keyword-directive">public</span> String getUsername() {
<span class="keyword-directive">return</span> username;
}
<span class="keyword-directive">public</span> String getCoolfactor() {
<span class="keyword-directive">return</span> coolfactor;
}
}
</pre>Unknownnoreply@blogger.com0tag:blogger.com,1999:blog-1401292818062153123.post-14730120616893166102009-10-20T13:22:00.000-07:002009-10-20T13:22:24.883-07:00JSP - list all parameter keys and values<pre><%@<span class="ST0">page</span> <span class="attribute-name">import</span>=<span class="attribute-value">"java.util.*"</span> %>
<%@<span class="ST0">page</span> <span class="attribute-name">contentType</span>=<span class="attribute-value">"text/html"</span> <span class="attribute-name">pageEncoding</span>=<span class="attribute-value">"UTF-8"</span>%>
<span class="ST1"><!DOCTYPE</span> <span class="ST1">HTML</span> <span class="ST1">PUBLIC</span> <span class="ST1">"-//W3C//DTD</span> <span class="ST1">HTML</span> <span class="ST1">4.01</span> <span class="ST1">Transitional//EN"</span>
<span class="ST1">"http://www.w3.org/TR/html4/loose.dtd"</span><span class="ST1">></span>
<span class="ST0"><</span><span class="ST0">html</span><span class="ST0">></span>
<span class="ST0"><</span><span class="ST0">head</span><span class="ST0">></span>
<span class="ST0"><</span><span class="ST0">meta</span> <span class="ST2">http-equiv</span><span class="ST2">=</span><span class="attribute-value">"Content-Type"</span> <span class="ST2">content</span><span class="ST2">=</span><span class="attribute-value">"text/html; charset=UTF-8"</span><span class="ST0">></span>
<span class="ST0"><</span><span class="ST0">title</span><span class="ST0">></span>JSP display all parameters<span class="ST0"></</span><span class="ST0">title</span><span class="ST0">></span>
<span class="ST0"></</span><span class="ST0">head</span><span class="ST0">></span>
<span class="ST0"><</span><span class="ST0">body</span><span class="ST0">></span>
<span class="scriptlet-delimiter"><%</span>
<span class="ST3">// you can get an enumeratable list</span>
<span class="ST3">// of parameter keys by using request.getParameterNames()</span>
Enumeration en = request.getParameterNames();
<span class="ST3">// enumerate through the keys and extract the values</span>
<span class="ST3">// from the keys!</span>
<span class="ST0">while</span> (en.hasMoreElements()) {
String parameterName = (String) en.nextElement();
String parameterValue = request.getParameter(parameterName);
out.println(parameterName+<span class="attribute-value">"</span><span class="attribute-value">:</span><span class="attribute-value">"</span>+parameterValue+<span class="attribute-value">"</span><span class="attribute-value"><br /></span><span class="attribute-value">"</span>);
}
<span class="ST3">// now call your jsp file (from a browser and add on some paramters)</span>
<span class="ST3">// file.jsp?a=12341234&b=apple&c=1.21gigawatts</span>
<span class="scriptlet-delimiter">%></span>
<span class="ST0"></</span><span class="ST0">body</span><span class="ST0">></span>
<span class="ST0"></</span><span class="ST0">html</span><span class="ST0">></span>
<span class="ST3"><!--</span>
<span class="ST3">output:</span>
<span class="ST3"> a:12341234</span>
<span class="ST3"> b:apple</span>
<span class="ST3"> c:1.21gigawatts</span>
<span class="ST3">--></span>
</pre>Unknownnoreply@blogger.com0tag:blogger.com,1999:blog-1401292818062153123.post-39322178039598765162009-10-20T12:29:00.000-07:002009-10-20T12:29:45.381-07:00JSP - include several differnt files to create content<pre><span class="ST0"><!-- This is the file "head.jsp" --></span>
<span class="ST0"><!-- This file just has head type info --></span>
<span class="ST1"><</span><span class="ST1">html</span><span class="ST1">></span>
<span class="ST1"><</span><span class="ST1">head</span><span class="ST1">></span>
<span class="ST1"><</span><span class="ST1">title</span><span class="ST1">></span>the title<span class="ST1"></</span><span class="ST1">title</span><span class="ST1">></span>
<span class="ST1"></</span><span class="ST1">head</span><span class="ST1">></span>
<span class="ST0"><!-- this is the file "body.jsp" --></span>
<span class="ST0"><!-- this file contains the content portion of the site --></span>
<span class="ST1"><</span><span class="ST1">body</span><span class="ST1">></span>
<span class="ST1"><</span><span class="ST1">p</span><span class="ST1">></span>
Content goes here
<span class="ST1"></</span><span class="ST1">p</span><span class="ST1">></span>
<span class="ST1"></</span><span class="ST1">body</span><span class="ST1">></span>
<span class="ST1"></</span><span class="ST1">html</span><span class="ST1">></span>
<span class="ST0"><!-- this is the file called main.jsp --></span>
<span class="ST0"><!-- this files purpose is to bring in all the</span>
<%@<span class="ST1"> include</span> <span class="attribute-name">file</span>=<span class="attribute-value">"head.jsp"</span> %>
<%@<span class="ST1"> include</span> <span class="attribute-name">file</span>=<span class="attribute-value">"body.jsp"</span> %>
<span class="scriptlet-delimiter"><%</span>
<span class="ST0">// When you include files you bring the file's data</span>
<span class="ST0">// (whether its html or jsp code) into the calling</span>
<span class="ST0">// page.</span>
<span class="scriptlet-delimiter">%></span>
</pre>Unknownnoreply@blogger.com0tag:blogger.com,1999:blog-1401292818062153123.post-53071186068930339182009-10-20T11:08:00.000-07:002009-10-20T11:08:01.919-07:00JSP - use directives to import java libraries<pre><%@<span class="ST0"> page</span> <span class="attribute-name">import</span>=<span class="attribute-value">"java.util.*"</span> %>
<%@<span class="ST0">page</span> <span class="attribute-name">contentType</span>=<span class="attribute-value">"text/html"</span> <span class="attribute-name">pageEncoding</span>=<span class="attribute-value">"UTF-8"</span>%>
<span class="ST1"><!DOCTYPE</span> <span class="ST1">HTML</span> <span class="ST1">PUBLIC</span> <span class="ST1">"-//W3C//DTD</span> <span class="ST1">HTML</span> <span class="ST1">4.01</span> <span class="ST1">Transitional//EN"</span>
<span class="ST1">"http://www.w3.org/TR/html4/loose.dtd"</span><span class="ST1">></span>
<span class="ST0"><</span><span class="ST0">html</span><span class="ST0">></span>
<span class="ST0"><</span><span class="ST0">head</span><span class="ST0">></span>
<span class="ST0"><</span><span class="ST0">meta</span> <span class="ST2">http-equiv</span><span class="ST2">=</span><span class="attribute-value">"Content-Type"</span> <span class="ST2">content</span><span class="ST2">=</span><span class="attribute-value">"text/html; charset=UTF-8"</span><span class="ST0">></span>
<span class="ST0"><</span><span class="ST0">title</span><span class="ST0">></span>JSP Page<span class="ST0"></</span><span class="ST0">title</span><span class="ST0">></span>
<span class="ST0"></</span><span class="ST0">head</span><span class="ST0">></span>
<span class="ST0"><</span><span class="ST0">body</span><span class="ST0">></span>
<span class="scriptlet-delimiter"><%</span>
ArrayList ll = <span class="ST0">new</span> ArrayList();
<span class="ST0">for</span> (<span class="ST0">int</span> i=0; i<100; i++) {
ll.add(i);
}
<span class="scriptlet-delimiter">%></span>
<span class="ST0"><</span><span class="ST0">h1</span><span class="ST0">></span>ArrayList size: <span class="scriptlet-delimiter"><%=</span> ll.size() <span class="scriptlet-delimiter">%></span> <span class="ST0"></</span><span class="ST0">h1</span><span class="ST0">></span>
<span class="ST0"><</span><span class="ST0">h1</span><span class="ST0">></span>Location of item 77: <span class="scriptlet-delimiter"><%=</span> ll.indexOf(77) <span class="scriptlet-delimiter">%></span> <span class="ST0"></</span><span class="ST0">h1</span><span class="ST0">></span>
<span class="ST0"></</span><span class="ST0">body</span><span class="ST0">></span>
<span class="ST0"></</span><span class="ST0">html</span><span class="ST0">></span>
</pre>Unknownnoreply@blogger.com0tag:blogger.com,1999:blog-1401292818062153123.post-38027709920549948122009-10-20T10:45:00.000-07:002009-10-20T10:45:09.101-07:00JSP - embedding scriptlets inside and around html<pre><%@<span class="ST0">page</span> <span class="attribute-name">contentType</span>=<span class="attribute-value">"text/html"</span> <span class="attribute-name">pageEncoding</span>=<span class="attribute-value">"UTF-8"</span>%>
<span class="ST1"><!DOCTYPE</span> <span class="ST1">HTML</span> <span class="ST1">PUBLIC</span> <span class="ST1">"-//W3C//DTD</span> <span class="ST1">HTML</span> <span class="ST1">4.01</span> <span class="ST1">Transitional//EN"</span>
<span class="ST1">"http://www.w3.org/TR/html4/loose.dtd"</span><span class="ST1">></span>
<span class="ST0"><</span><span class="ST0">html</span><span class="ST0">></span>
<span class="ST0"><</span><span class="ST0">head</span><span class="ST0">></span>
<span class="ST0"><</span><span class="ST0">meta</span> <span class="ST2">http-equiv</span><span class="ST2">=</span><span class="attribute-value">"Content-Type"</span> <span class="ST2">content</span><span class="ST2">=</span><span class="attribute-value">"text/html; charset=UTF-8"</span><span class="ST0">></span>
<span class="ST0"><</span><span class="ST0">title</span><span class="ST0">></span>JSP Page<span class="ST0"></</span><span class="ST0">title</span><span class="ST0">></span>
<span class="ST0"></</span><span class="ST0">head</span><span class="ST0">></span>
<span class="ST0"><</span><span class="ST0">body</span><span class="ST0">></span>
<span class="scriptlet-delimiter"><%</span>
<span class="ST3">// if you need to accomplish a repetitive task</span>
<span class="ST3">// like creating a list of 1,000 numbers and</span>
<span class="ST3">// putting them in a bulletted list then</span>
<span class="ST3">// keep in mind that scriptlets can be your</span>
<span class="ST3">// friend.</span>
<span class="ST3">// You notice below that the for loop spans several</span>
<span class="ST3">// pieces of the scriptlet</span>
<span class="scriptlet-delimiter">%></span>
<span class="ST0"><</span><span class="ST0">ul</span><span class="ST0">></span>
<span class="scriptlet-delimiter"><%</span>
<span class="ST0">for</span> (<span class="ST0">int</span> i=0; i<1000; i++) {
<span class="scriptlet-delimiter">%></span>
<span class="ST0"><</span><span class="ST0">li</span><span class="ST0">></span><span class="scriptlet-delimiter"><%=</span> i <span class="scriptlet-delimiter">%></span><span class="ST0"></</span><span class="ST0">li</span><span class="ST0">></span>
<span class="scriptlet-delimiter"><%</span>
}
<span class="scriptlet-delimiter">%></span>
<span class="ST0"></</span><span class="ST0">ul</span><span class="ST0">></span>
<span class="ST0"></</span><span class="ST0">body</span><span class="ST0">></span>
<span class="ST0"></</span><span class="ST0">html</span><span class="ST0">></span>
<span class="ST3"><!--</span>
<span class="ST3">0</span>
<span class="ST3">1</span>
<span class="ST3">2</span>
<span class="ST3">3</span>
<span class="ST3">...</span>
<span class="ST3">[SNIP]</span>
<span class="ST3">...</span>
<span class="ST3">998</span>
<span class="ST3">999</span>
<span class="ST3">--></span>
</pre>Unknownnoreply@blogger.com0tag:blogger.com,1999:blog-1401292818062153123.post-23468710443836970572009-10-20T10:35:00.000-07:002009-10-20T10:35:40.807-07:00JSP - declare methods and variables from within a jsp page<pre><%@<span class="ST0">page</span> <span class="attribute-name">contentType</span>=<span class="attribute-value">"text/html"</span> <span class="attribute-name">pageEncoding</span>=<span class="attribute-value">"UTF-8"</span>%>
<span class="ST1"><!DOCTYPE</span> <span class="ST1">HTML</span> <span class="ST1">PUBLIC</span> <span class="ST1">"-//W3C//DTD</span> <span class="ST1">HTML</span> <span class="ST1">4.01</span> <span class="ST1">Transitional//EN"</span>
<span class="ST1">"http://www.w3.org/TR/html4/loose.dtd"</span><span class="ST1">></span>
<span class="ST0"><</span><span class="ST0">html</span><span class="ST0">></span>
<span class="ST0"><</span><span class="ST0">head</span><span class="ST0">></span>
<span class="ST0"><</span><span class="ST0">meta</span> <span class="ST2">http-equiv</span><span class="ST2">=</span><span class="attribute-value">"Content-Type"</span> <span class="ST2">content</span><span class="ST2">=</span><span class="attribute-value">"text/html; charset=UTF-8"</span><span class="ST0">></span>
<span class="ST0"><</span><span class="ST0">title</span><span class="ST0">></span>JSP Page<span class="ST0"></</span><span class="ST0">title</span><span class="ST0">></span>
<span class="ST0"></</span><span class="ST0">head</span><span class="ST0">></span>
<span class="ST0"><</span><span class="ST0">body</span><span class="ST0">></span>
<span class="scriptlet-delimiter"><%!</span>
<span class="ST3">// You can do real coding inside of here!</span>
<span class="ST3">// The code in this section is called a scriptlet.</span>
<span class="ST3">// Any functions or variables you create can</span>
<span class="ST3">// be used later in the file with jsp expression</span>
<span class="ST3">// tags or shortcuts</span>
<span class="ST3">// You'll notice that the section began with a</span>
<span class="ST3">// <%! ......this allows you to declare methods</span>
String s = <span class="attribute-value">"</span><span class="attribute-value">Declare methods and variables with scriptlets.</span><span class="attribute-value">"</span>;
<span class="ST0">int</span> getNum() {
<span class="ST0">if</span> (1>0){
<span class="ST0">return</span> 100;
}
<span class="ST0">return</span> 111;
}
<span class="scriptlet-delimiter">%></span>
<span class="ST0"><</span><span class="ST0">h1</span><span class="ST0">></span><span class="scriptlet-delimiter"><%=</span> s <span class="scriptlet-delimiter">%></span><span class="ST0"></</span><span class="ST0">h1</span><span class="ST0">></span>
<span class="ST0"><</span><span class="ST0">h2</span><span class="ST0">></span><span class="scriptlet-delimiter"><%</span><span class="scriptlet-delimiter">=</span> getNum() <span class="scriptlet-delimiter">%></span><span class="ST0"></</span><span class="ST0">h2</span><span class="ST0">></span>
<span class="ST0"></</span><span class="ST0">body</span><span class="ST0">></span>
<span class="ST0"></</span><span class="ST0">html</span><span class="ST0">></span>
</pre>Unknownnoreply@blogger.com0tag:blogger.com,1999:blog-1401292818062153123.post-699980413825381892009-10-20T10:23:00.000-07:002009-10-20T10:23:30.051-07:00JSP - print direct to html<pre><%@<span class="ST0">page</span> <span class="attribute-name">contentType</span>=<span class="attribute-value">"text/html"</span> <span class="attribute-name">pageEncoding</span>=<span class="attribute-value">"UTF-8"</span>%>
<span class="ST1"><!DOCTYPE</span> <span class="ST1">HTML</span> <span class="ST1">PUBLIC</span> <span class="ST1">"-//W3C//DTD</span> <span class="ST1">HTML</span> <span class="ST1">4.01</span> <span class="ST1">Transitional//EN"</span>
<span class="ST1">"http://www.w3.org/TR/html4/loose.dtd"</span><span class="ST1">></span>
<span class="ST0"><</span><span class="ST0">html</span><span class="ST0">></span>
<span class="ST0"><</span><span class="ST0">head</span><span class="ST0">></span>
<span class="ST0"><</span><span class="ST0">meta</span> <span class="ST2">http-equiv</span><span class="ST2">=</span><span class="attribute-value">"Content-Type"</span> <span class="ST2">content</span><span class="ST2">=</span><span class="attribute-value">"text/html; charset=UTF-8"</span><span class="ST0">></span>
<span class="ST0"><</span><span class="ST0">title</span><span class="ST0">></span>JSP print straight out example<span class="ST0"></</span><span class="ST0">title</span><span class="ST0">></span>
<span class="ST0"></</span><span class="ST0">head</span><span class="ST0">></span>
<span class="ST0"><</span><span class="ST0">body</span><span class="ST0">></span>
<span class="scriptlet-delimiter"><%</span>
out.println(<span class="attribute-value">"</span><span class="attribute-value"><h1>Print directly example</h1></span><span class="attribute-value">"</span>);
out.println(<span class="attribute-value">"</span><span class="attribute-value">Here is the date:<br /></span><span class="attribute-value">"</span>);
out.println(<span class="ST0">new</span> java.util.Date());
<span class="scriptlet-delimiter">%></span>
<span class="ST0"></</span><span class="ST0">body</span><span class="ST0">></span>
<span class="ST0"></</span><span class="ST0">html</span><span class="ST0">></span>
<span class="ST3"><!--</span>
<span class="ST3">my output:</span>
<span class="ST3"> Print directly example</span>
<span class="ST3"> Here is the date:</span>
<span class="ST3"> Tue Oct 20 11:21:21 MDT 2009</span>
<span class="ST3">--></span>
</pre>Unknownnoreply@blogger.com0tag:blogger.com,1999:blog-1401292818062153123.post-9605362997871667042009-10-20T09:57:00.000-07:002009-10-20T09:57:35.279-07:00JSP - insert simple data with jsp expression<pre><%@<span class="ST0">page</span> <span class="attribute-name">contentType</span>=<span class="attribute-value">"text/html"</span> <span class="attribute-name">pageEncoding</span>=<span class="attribute-value">"UTF-8"</span>%>
<span class="ST1"><!DOCTYPE</span> <span class="ST1">HTML</span> <span class="ST1">PUBLIC</span> <span class="ST1">"-//W3C//DTD</span> <span class="ST1">HTML</span> <span class="ST1">4.01</span> <span class="ST1">Transitional//EN"</span>
<span class="ST1">"http://www.w3.org/TR/html4/loose.dtd"</span><span class="ST1">></span>
<span class="ST0"><</span><span class="ST0">html</span><span class="ST0">></span>
<span class="ST0"><</span><span class="ST0">head</span><span class="ST0">></span>
<span class="ST0"><</span><span class="ST0">meta</span> <span class="ST2">http-equiv</span><span class="ST2">=</span><span class="attribute-value">"Content-Type"</span> <span class="ST2">content</span><span class="ST2">=</span><span class="attribute-value">"text/html; charset=UTF-8"</span><span class="ST0">></span>
<span class="ST0"><</span><span class="ST0">title</span><span class="ST0">></span>java expression example<span class="ST0"></</span><span class="ST0">title</span><span class="ST0">></span>
<span class="ST0"></</span><span class="ST0">head</span><span class="ST0">></span>
<span class="ST0"><</span><span class="ST0">body</span><span class="ST0">></span>
<span class="ST0"><</span><span class="ST0">h1</span><span class="ST0">></span>A JSP TimeDate Stamp Example<span class="ST0"></</span><span class="ST0">h1</span><span class="ST0">></span>
<span class="ST3"><!--</span>
<span class="ST3"> you can use jsp expressions with the</span>
<span class="ST3"> shortcut percent equals or you can use</span>
<span class="ST3"> jsp:expression tags</span>
<span class="ST3"> --></span>
<span class="ST0"><</span><span class="ST0">p</span><span class="ST0">></span> Here is the date using the shortcut
percent equals syntax:<span class="ST0"><</span><span class="ST0">br</span> <span class="ST0">/></span>
<span class="scriptlet-delimiter"><%=</span> <span class="ST0">new</span> java.util.Date() <span class="scriptlet-delimiter">%></span> <span class="ST0"></</span><span class="ST0">p</span><span class="ST0">></span>
<span class="ST0"><</span><span class="ST0">p</span><span class="ST0">></span> Here is the same date stamp using the
jsp expression tags: <span class="ST0"><</span><span class="ST0">br</span> <span class="ST0">/></span>
<<span class="ST0">jsp:expression</span>>new java.util.Date()</<span class="ST4">jsp:expression</span>><span class="ST0"></</span><span class="ST0">p</span><span class="ST0">></span>
<span class="ST0"></</span><span class="ST0">body</span><span class="ST0">></span>
<span class="ST0"></</span><span class="ST0">html</span><span class="ST0">></span>
<span class="ST3"><!-- Here is my output:</span>
<span class="ST3">A JSP TimeDate Stamp Example</span>
<span class="ST3">Here is the date using the shortcut percent equals syntax:</span>
<span class="ST3">Tue Oct 20 10:52:53 MDT 2009</span>
<span class="ST3">Here is the same date stamp using the jsp expression tags:</span>
<span class="ST3">Tue Oct 20 10:52:53 MDT 2009</span>
<span class="ST3">--></span>
</pre>Unknownnoreply@blogger.com0tag:blogger.com,1999:blog-1401292818062153123.post-7913688947779781622009-10-06T20:36:00.001-07:002009-10-06T20:36:39.905-07:00Java - pig latin generator<pre>
<span class="keyword-directive">package</span> javasomethingsomething;
<span class="keyword-directive">public</span> <span class="keyword-directive">class</span> Main {
<span class="keyword-directive">public</span> <span class="keyword-directive">static</span> <span class="keyword-directive">void</span> main(String[] args) {
<span class="comment">// all the heavy lifting is done in the PigLatin class</span>
PigLatin pg = <span class="keyword-directive">new</span> PigLatin();
String pigSentence = <span class="character">""</span>;
String sentence = <span class="character">"</span><span class="character">This is going to be a pig latin sentence</span><span class="character">"</span>;
<span class="comment">// iterate over the sentence with for-each and split by " "</span>
<span class="keyword-directive">for</span> (String s:sentence.split(<span class="character">"</span> <span class="character">"</span>)) {
pigSentence += pg.getPigLatinForWord(s) + <span class="character">"</span> <span class="character">"</span>;
}
<span class="comment">// added the trim to remove the trailing space</span>
System.out.println(pigSentence.trim());
}
}
<span class="keyword-directive">class</span> PigLatin{
<span class="keyword-directive">public</span> String getPigLatinForWord(String word) {
<span class="keyword-directive">int</span> firstVowel = word.length();
<span class="comment">// yes, I included y as a vowel!!</span>
String[] vowels = {<span class="character">"</span><span class="character">a</span><span class="character">"</span>, <span class="character">"</span><span class="character">e</span><span class="character">"</span>, <span class="character">"</span><span class="character">i</span><span class="character">"</span>, <span class="character">"</span><span class="character">o</span><span class="character">"</span>, <span class="character">"</span><span class="character">u</span><span class="character">"</span>, <span class="character">"</span><span class="character">y</span><span class="character">"</span>};
<span class="keyword-directive">for</span>(String s:vowels){
<span class="comment">// if indexOf() finds no match it returns -1</span>
<span class="keyword-directive">if</span> ((word.indexOf(s) < firstVowel) && (word.indexOf(s) != -1)) {
firstVowel = word.indexOf(s);
}
}
<span class="keyword-directive">return</span> word.substring(firstVowel, word.length()) +
word.substring(0, firstVowel) +
<span class="character">"</span><span class="character">ay</span><span class="character">"</span>;
}
}
</pre>Unknownnoreply@blogger.com0tag:blogger.com,1999:blog-1401292818062153123.post-75858543329825062062009-09-25T13:33:00.000-07:002009-09-25T13:33:00.668-07:00Java - a ping example with java's InetAddress.isReachable()<pre>
<span class="keyword-directive">import</span> java.net.*;
<span class="keyword-directive">public</span> <span class="keyword-directive">class</span> Main {
<span class="keyword-directive">public</span> <span class="keyword-directive">static</span> <span class="keyword-directive">void</span> main(String[] args) {
<span class="keyword-directive">try</span>{
<span class="comment">// a note:</span>
<span class="comment">// This the isReachable method is problematic</span>
<span class="comment">// If you are in a coorporate environment</span>
<span class="comment">// then you are probably (unknown to you)</span>
<span class="comment">// using proxy servers. Java needs to know</span>
<span class="comment">// what the proxy server and port is</span>
<span class="comment">// DhttpProxy.host=yourproxyhost.com -DhttpProxy.port</span>
<span class="comment">//</span>
<span class="comment">// All of testing I've done at home works fine.</span>
<span class="comment">// You need to configure java to utilize your proxy</span>
<span class="comment">// gather the ip address associated with the host</span>
InetAddress[] addresses = InetAddress.getAllByName(<span class="character">"</span><span class="character">yahoo.com</span><span class="character">"</span>);
<span class="comment">// iterate through the ip address with for-each</span>
<span class="keyword-directive">for</span> (InetAddress addr:addresses) {
<span class="comment">// the timeout is in milliseconds 2 seconds here</span>
<span class="keyword-directive">if</span> (addr.isReachable(2000)){
System.out.printf(<span class="character">"</span><span class="character">%s is reachable</span><span class="character">"</span>, addr);
System.out.println();
}
<span class="keyword-directive">else</span>{
System.out.printf(<span class="character">"</span><span class="character">%s is not reachable</span><span class="character">"</span>, addr);
System.out.println();
}
}
}
<span class="keyword-directive">catch</span>(Exception e) {
System.out.println(<span class="character">"</span><span class="character">host is unknown (or unresolvable)</span><span class="character">"</span>);
}
}
}
<span class="comment">/*</span>
<span class="comment"> * Output (for me):</span>
<span class="comment"> yahoo.com/69.147.114.224 is reachable</span>
<span class="comment"> yahoo.com/209.131.36.159 is reachable</span>
<span class="comment"> yahoo.com/209.191.93.53 is reachable</span>
<span class="comment">*/</span>
</pre>Unknownnoreply@blogger.com0tag:blogger.com,1999:blog-1401292818062153123.post-82816709626877045532009-09-25T12:16:00.000-07:002009-09-25T12:16:09.624-07:00Java - reverse the word order of a sentence<pre><span class="keyword-directive">public</span> <span class="keyword-directive">class</span> Main {
<span class="keyword-directive">public</span> <span class="keyword-directive">static</span> <span class="keyword-directive">void</span> main(String[] args) {
Words w = <span class="keyword-directive">new</span> Words();
String sentence = <span class="character">"</span><span class="character">The example sentence is here</span><span class="character">"</span>;
System.out.println(sentence);
System.out.println(<span class="character">"</span><span class="character">reversed to:</span><span class="character">"</span>);
System.out.println(w.reverseWordOrderOfSentence(sentence));
}
}
<span class="keyword-directive">class</span> Words{
<span class="keyword-directive">public</span> String reverseWordOrderOfSentence(String sentence){
<span class="comment">// split up by words</span>
String[] words = sentence.split(<span class="character">"</span> <span class="character">"</span>);
sentence = <span class="character">""</span>;
<span class="comment">// iterate backward through the array</span>
<span class="comment">// rebuilding the sentence from the back forward</span>
<span class="keyword-directive">for</span> (<span class="keyword-directive">int</span> i=words.length; i>0; i--){
sentence += words[i-1];
sentence += <span class="character">"</span> <span class="character">"</span>;
}
<span class="comment">// remove the trailing white space</span>
<span class="keyword-directive">return</span> sentence.trim();
}
}
<span class="comment">/*</span>
<span class="comment"> * OUTPUT:</span>
<span class="comment"> The example sentence is here</span>
<span class="comment"> reversed to:</span>
<span class="comment"> here is sente</span><span class="comment">nce example The</span>
<span class="comment">*/</span>
</pre>Unknownnoreply@blogger.com0tag:blogger.com,1999:blog-1401292818062153123.post-88758487873896977822009-09-25T11:49:00.000-07:002009-09-25T11:50:28.775-07:00Java - extracting rgb values from an image<pre><span class="keyword-directive">import</span> javax.imageio.*;
<span class="keyword-directive">import</span> java.awt.image.*;
<span class="keyword-directive">import</span> java.io.*;
<span class="keyword-directive">p</span><span class="keyword-directive">ublic</span> <span class="keyword-directive">class</span> Main {
<span class="keyword-directive">public</span> <span class="keyword-directive">static</span> <span class="keyword-directive">void</span> main(String[] args) {
BufferedImage bimg = <span class="keyword-directive">null</span>;
String input = <span class="character">"</span><span class="character">test.jpg</span><span class="character">"</span>;
<span class="keyword-directive">try</span>{
bimg = ImageIO.read(<span class="keyword-directive">new</span> File(input));
}
<span class="keyword-directive">catch</span> (Exception e) {
<span class="comment">// the test.jpg must be in the <a href="http://javaprose.blogspot.com/2009/09/java-find-working-directory.html">working dir</a> </span>
System.out.println(input + <span class="character">"</span><span class="character"> is not in working dir</span><span class="character">"</span>);
}
System.out.println(<span class="character">"</span><span class="character">height: </span><span class="character">"</span> + Integer.toString(bimg.getHeight()));
System.out.println(<span class="character">"</span><span class="character">width: </span><span class="character">"</span> + Integer.toString(bimg.getWidth()));
<span class="comment">// collect the rgb information</span>
<span class="comment">// regarding a single pixel</span>
<span class="keyword-directive">int</span> rgb = bimg.getRGB(10, 10);
<span class="comment">// for some smart reason (that is beyond me)</span>
<span class="comment">// getting the rgb gives you a single int</span>
<span class="comment">//</span>
<span class="comment">// each component of colr occupies 8 bits</span>
<span class="comment">// this extracts the actual alpha, red, green, blue</span>
<span class="keyword-directive">int</span> a = (rgb >>> 24) & 0xFF;
<span class="keyword-directive">int</span> r = (rgb >>> 16) & 0xFF;
<span class="keyword-directive">int</span> g = (rgb >>> 8) & 0xFF;
<span class="keyword-directive">int</span> b = (rgb >>> 0) & 0xFF;
<span class="comment">// here is the proof</span>
System.out.println(<span class="character">"</span><span class="character">a: </span><span class="character">"</span> + Integer.toString(a));
System.out.println(<span class="character">"</span><span class="character">r: </span><span class="character">"</span> + Integer.toString(r));
System.out.println(<span class="character">"</span><span class="character">g: </span><span class="character">"</span> + Integer.toString(g));
System.out.println(<span class="character">"</span><span class="character">b: </span><span class="character">"</span> + Integer.toString(b));
<span class="comment">// this scripts output:</span>
<span class="comment">/*</span>
<span class="comment"> height: 564</span>
<span class="comment"> width: 634</span>
<span class="comment"> a: 255</span>
<span class="comment"> r: 222</span>
<span class="comment"> g: 128</span>
<span class="comment"> b: 184</span>
<span class="comment"> */</span>
}
}
</pre>Unknownnoreply@blogger.com0tag:blogger.com,1999:blog-1401292818062153123.post-90669714089614898512009-09-25T06:19:00.000-07:002009-09-25T06:19:20.562-07:00Java - remove vowels from a sentence String<pre><span class="keyword-directive">public</span> <span class="keyword-directive">class</span> Main {
<span class="keyword-directive">public</span> <span class="keyword-directive">static</span> <span class="keyword-directive">void</span> main(String[] args) {
NotStatic g = <span class="keyword-directive">new</span> NotStatic();
String sentence = <span class="character">"</span><span class="character">This is my example sentence.</span><span class="character">"</span>;
String s = g.RemoveVowelsFromSentence(sentence);
System.out.println(s);
<span class="comment">// output:</span>
<span class="comment">// Ths s m xmpl sntnc.</span>
}
}
<span class="keyword-directive">class</span> NotStatic {
<span class="keyword-directive">public</span> String RemoveVowelsFromSentence(String sentence) {
String[] vowels = {<span class="character">"</span><span class="character">a</span><span class="character">"</span>, <span class="character">"</span><span class="character">e</span><span class="character">"</span>, <span class="character">"</span><span class="character">i</span><span class="character">"</span>, <span class="character">"</span><span class="character">o</span><span class="character">"</span>, <span class="character">"</span><span class="character">u</span><span class="character">"</span>, <span class="character">"</span><span class="character">y</span><span class="character">"</span>};
<span class="comment">// iterate through the vowel array with for-each</span>
<span class="keyword-directive">for</span> (String s:vowels){
sentence = sentence.replaceAll(s, <span class="character">""</span>);
}
<span class="keyword-directive">return</span> sentence;
}
}
</pre>Unknownnoreply@blogger.com0tag:blogger.com,1999:blog-1401292818062153123.post-19022006988960704832009-09-25T05:57:00.000-07:002009-09-25T05:57:28.572-07:00Java - Hashtable example - how to create and use<pre><span class="keyword-directive">import</span> java.util.*;
<span class="keyword-directive">public</span> <span class="keyword-directive">class</span> Main {
<span class="keyword-directive">public</span> <span class="keyword-directive">static</span> <span class="keyword-directive">void</span> main(String[] args) {
<span class="comment">// a hashtable is like a dictionary</span>
<span class="comment">// to put items into the hashtable you </span>
<span class="comment">// need a key and a value. The keys must</span>
<span class="comment">// be unique -- while the values can be</span>
<span class="comment">// anything you like</span>
Hashtable ht = <span class="keyword-directive">new</span> Hashtable();
<span class="comment">// put new values into ht</span>
ht.put(<span class="character">"</span><span class="character">name</span><span class="character">"</span>, <span class="character">"</span><span class="character">Steve</span><span class="character">"</span>);
ht.put(<span class="character">"</span><span class="character">warpFactor</span><span class="character">"</span>, 9);
String s = <span class="character">""</span>;
<span class="comment">// looping add</span>
<span class="keyword-directive">for</span> (<span class="keyword-directive">int</span> i=0; i<20; i++) {
s = Integer.toString(i);
s += <span class="character">"</span><span class="character"> is a good number</span><span class="character">"</span>;
ht.put(i, s);
}
<span class="comment">// use the values in the hashtable</span>
System.out.println(<span class="character">"</span><span class="character">I hear that </span><span class="character">"</span> +
ht.get(<span class="character">"</span><span class="character">name</span><span class="character">"</span>).toString() +
<span class="character">"</span><span class="character"> has a Warp Factor of </span><span class="character">"</span> +
ht.get(<span class="character">"</span><span class="character">warpFactor</span><span class="character">"</span>).toString());
<span class="comment">// outputs:</span>
<span class="comment">// I hear that Steve has a Warp Factor of 9</span>
}
}
</pre>Unknownnoreply@blogger.com0tag:blogger.com,1999:blog-1401292818062153123.post-15428580342431129902009-09-25T05:41:00.000-07:002009-09-25T05:43:24.438-07:00Java - how to create and use a LinkedList<pre><span class="keyword-directive">import</span> java.util.*;
<span class="keyword-directive">public</span> <span class="keyword-directive">class</span> Main {
<span class="keyword-directive">public</span> <span class="keyword-directive">static</span> <span class="keyword-directive">void</span> main(String[] args) {
LinkedList ll = <span class="keyword-directive">new</span> LinkedList();
<span class="comment">// add to linked list</span>
ll.add(<span class="character">"</span><span class="character">first String object</span><span class="character">"</span>);
<span class="comment">// total items in the linked list</span>
System.out.println(ll.size());
<span class="comment">// indicates: 1</span>
<span class="comment">// the list is not type specific</span>
<span class="comment">// Strings and ints can coexist</span>
ll.add(22);
<span class="comment">// add ten more items</span>
<span class="keyword-directive">for</span> (<span class="keyword-directive">int</span> i=0; i<10; i++){
ll.add(i);
}
String oType = <span class="character">""</span>;
<span class="comment">// iterate through all existing items</span>
<span class="comment">// with for-each</span>
<span class="keyword-directive">for</span>(Object o:ll){
oType = o.getClass().toString();
System.out.println(o.toString() +
<span class="character">"</span><span class="character">, is type: </span><span class="character">"</span> + oType);
}
<span class="comment">// remove items from list</span>
ll.removeFirstOccurrence(3);
<span class="comment">// remove the first item from the list</span>
ll.remove();
<span class="comment">// remove the last item from the list</span>
ll.removeLast();
}
}
</pre>Unknownnoreply@blogger.com0tag:blogger.com,1999:blog-1401292818062153123.post-14510295949597182032009-09-24T21:26:00.000-07:002009-09-24T21:26:17.066-07:00Java - how to create and use a Vector<pre><span class="keyword-directive">import</span> java.util.*;
<span class="keyword-directive">public</span> <span class="keyword-directive">class</span> Main {
<span class="keyword-directive">public</span> <span class="keyword-directive">static</span> <span class="keyword-directive">void</span> main(String[] args) {
Vector v = <span class="keyword-directive">new</span> Vector();
<span class="comment">// The Vector class is almost identical to the</span>
<span class="comment">// ArrayList class. The main difference is that</span>
<span class="comment">// a Vector is thread safe.</span>
v.add(<span class="character">"</span><span class="character">number one is a String</span><span class="character">"</span>);
v.add(22); <span class="comment">// number two is an Integer</span>
<span class="keyword-directive">for</span> (<span class="keyword-directive">int</span> i=0; i<10; i++){
<span class="comment">// add ten integers</span>
v.add(i);
}
<span class="comment">// iterate through the vector with a foreach</span>
<span class="keyword-directive">for</span> (Object o:v){
System.out.println(o);
}
<span class="comment">// as with ArrayLists you'll notice that</span>
<span class="comment">// Vectors are not type specific. You can</span>
<span class="comment">// put in whatever you want</span>
}
}
</pre>Unknownnoreply@blogger.com0tag:blogger.com,1999:blog-1401292818062153123.post-61437420238197692952009-09-24T21:13:00.001-07:002009-09-24T21:19:50.578-07:00Java - how to create and use an ArrayList<pre><span class="keyword-directive">import</span> java.util.*;
<span class="comment">// related posts:</span>
<span class="comment">// <a href="http://javaprose.blogspot.com/2009/09/java-create-and-use-string-or-int-array.html">old (but fast) school array</a></span>
<span class="comment">// <a href="">Thread safe vectors</a></span>
<span class="comment">// <a href=""></a></span>
<span class="comment">// <a href=""></a></span>
<span class="keyword-directive">public</span> <span class="keyword-directive">class</span> Main {
<span class="keyword-directive">public</span> <span class="keyword-directive">static</span> <span class="keyword-directive">void</span> main(String[] args) {
<span class="comment">// arraylists do not require a size definition</span>
<span class="comment">// when you declare or instantiate.</span>
<span class="comment">// you can add to your hearts content</span>
ArrayList al = <span class="keyword-directive">new</span> ArrayList();
al.add(<span class="character">"</span><span class="character">number one</span><span class="character">"</span>);
<span class="comment">// display the size of the ArrayList</span>
System.out.println(al.size());
<span class="comment">// indicates: 1</span>
<span class="comment">// fill up with 10</span>
<span class="keyword-directive">for</span> (<span class="keyword-directive">int</span> i=0; i<10; i++){
<span class="comment">// you'll notice that it just appends to</span>
<span class="comment">// the existing list. "number one" remains</span>
<span class="comment">// and all the numbers are tacked on after</span>
al.add(i);
}
<span class="comment">// display all ten with foreach</span>
<span class="comment">//for (Object o:al</span>
<span class="keyword-directive">for</span> (<span class="keyword-directive">int</span> i=0; i<al.size(); i++){
System.out.println(al.get(i) + <span class="character">"</span><span class="character"> is type </span><span class="character">"</span> +
al.get(i).getClass().toString());
}
<span class="comment">// you'll notice from the output that a Java ArrayList</span>
<span class="comment">// can have a mixture of object types. Here we</span>
<span class="comment">// blend Integer and String</span>
}
}
</pre>Unknownnoreply@blogger.com0tag:blogger.com,1999:blog-1401292818062153123.post-35145800761705300782009-09-24T21:01:00.000-07:002009-09-24T21:01:49.160-07:00Java - create and use a String or int array<pre>
<span class="keyword-directive">public</span> <span class="keyword-directive">class</span> Main {
<span class="keyword-directive">public</span> <span class="keyword-directive">static</span> <span class="keyword-directive">void</span> main(String[] args) {
<span class="comment">// standard, fast, old school array</span>
<span class="comment">// string array</span>
String[] stringArray = <span class="keyword-directive">new</span> String[10];
stringArray[0] = <span class="character">"</span><span class="character">first item in array</span><span class="character">"</span>;
System.out.println(<span class="character">"</span><span class="character">array length: </span><span class="character">"</span> + stringArray.length);
<span class="comment">// indicates: 10</span>
<span class="comment">// even if you've only populated</span>
<span class="comment">// one of the you allocated room for 10</span>
<span class="comment">// you can also for loop through and populate</span>
String tempString = <span class="character">""</span>;
<span class="keyword-directive">for</span> (<span class="keyword-directive">int</span> i=0; i<stringArray.length; i++){
tempString = Integer.toString(i+1);
stringArray[i] = <span class="character">"</span><span class="character">arrayitem </span><span class="character">"</span> + tempString;
}
<span class="comment">// display contents of array</span>
<span class="comment">// with a for each</span>
<span class="keyword-directive">for</span> (String s:stringArray){
System.out.println(s);
}
<span class="comment">// same methodology for an int array</span>
<span class="keyword-directive">int</span>[] intArray = <span class="keyword-directive">new</span> <span class="keyword-directive">int</span>[10];
intArray[0] = 213;
}
}
</pre>Unknownnoreply@blogger.com0tag:blogger.com,1999:blog-1401292818062153123.post-51092059561936452442009-09-24T15:10:00.000-07:002009-09-24T15:10:42.893-07:00Java - find the working directory<style type="text/css">
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</style> <br />
<pre><span class="keyword-directive">import</span> java.util.*;
<span class="keyword-directive">public</span> <span class="keyword-directive">class</span> Main {
<span class="keyword-directive">public</span> <span class="keyword-directive">static</span> <span class="keyword-directive">void</span> main(String[] args) {
<span class="comment">// to find out where your application is running</span>
<span class="comment">// (sounds easy but its sometimes tricky)</span>
System.out.println(<span class="character">"</span><span class="character">This Java applications working directory is:</span><span class="character">"</span>);
<span class="comment">// Java has a list of Properties that it uses for everything</span>
<span class="comment">// the working directory property is user.dir</span>
<span class="comment">// you can check it out with:</span>
System.out.println(System.getProperty(<span class="character">"</span><span class="character">user.dir</span><span class="character">"</span>));
<span class="comment">// you can see all the properties with this:</span>
System.out.println(System.getProperties());
<span class="comment">// it will just dump them all out in a not</span>
<span class="comment">// organized way</span>
<span class="comment">// you can also iterate through all of the properties</span>
<span class="comment">// and print them out line by linewith:</span>
Properties myProps = System.getProperties();
<span class="keyword-directive">for</span> (Enumeration e = myProps.keys(); e.hasMoreElements();<span class="comment">/**/</span>){
String key = (String)e.nextElement();
String value = myProps.getProperty(key);
System.out.println(key + <span class="character">"</span><span class="character"> = </span><span class="character">"</span> + value);
}
}
}
</pre>Unknownnoreply@blogger.com0tag:blogger.com,1999:blog-1401292818062153123.post-32986680636077435012009-09-24T06:34:00.000-07:002009-09-24T15:18:17.114-07:00Java - open and read text file<style type="text/css">
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table {color: #000000; background-color: #e9e8e2; font-family: Monospaced; font-weight: bold}
.comment {color: #969696}
.character {color: #ce7b00}
.keyword-directive {color: #0000e6}
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</style> <br />
<br />
<pre><span class="comment">/*</span>
<span class="comment"> * To change this template, choose Tools | Templates</span>
<span class="comment"> * and open the template in the editor.</span>
<span class="comment"> */</span>
<span class="keyword-directive">package</span> readfile;
<span class="keyword-directive">import</span> java.io.*;
<span class="keyword-directive">public</span> <span class="keyword-directive">class</span> Main {
<span class="keyword-directive">public</span> <span class="keyword-directive">static</span> <span class="keyword-directive">void</span> main(String[] args) {
<span class="comment">// this assumes you have 'test.txt' in your <a href"http://javaprose.blogspot.com/2009/09/java-find-working-directory.html">working directory</a></span>
String filename = <span class="character">"</span><span class="character">test.txt</span><span class="character">"</span>;
<span class="keyword-directive">try</span> {
<span class="comment">// open file</span>
BufferedReader reader = <span class="keyword-directive">new</span> BufferedReader(<span class="keyword-directive">new</span> FileReader(filename));
String line;
<span class="comment">// iterate through file's lines</span>
<span class="keyword-directive">while</span> ((line = reader.readLine()) != <span class="keyword-directive">null</span>) {
System.out.println(line);
}
reader.close();
}
<span class="keyword-directive">catch</span>(Exception e) {
System.out.println(<span class="character">"</span><span class="character">file not found</span><span class="character">"</span>);
System.out.println(e.getMessage());
System.out.println(e.toString());
}
}
}
<span class="comment">// output (for my test file):</span>
<span class="comment">// one</span>
<span class="comment">// two</span>
<span class="comment">// three</span>
</pre>Unknownnoreply@blogger.com0tag:blogger.com,1999:blog-1401292818062153123.post-3522139392356010122009-09-23T19:42:00.000-07:002009-09-23T19:42:48.775-07:00Java - cast int to string and string to int<span class="Apple-style-span" style="font-family: Monospaced; font-weight: bold;"></span><br />
<pre><span class="keyword-directive" style="color: #0000e6;">public</span> <span class="keyword-directive" style="color: #0000e6;">class</span> Main {
<span class="keyword-directive" style="color: #0000e6;">public</span> <span class="keyword-directive" style="color: #0000e6;">static</span> <span class="keyword-directive" style="color: #0000e6;">void</span> main(String[] args) {
String s = <span class="character" style="color: #ce7b00;">"</span><span class="character" style="color: #ce7b00;">23</span><span class="character" style="color: #ce7b00;">"</span>;
<span class="keyword-directive" style="color: #0000e6;">int</span> i = 22;
<span class="comment" style="color: #969696;">// int to string</span>
String iString = Integer.toString(i);
System.out.println(iString);
<span class="comment" style="color: #969696;">// output:</span>
<span class="comment" style="color: #969696;">// 22</span>
<span class="comment" style="color: #969696;">// string to int</span>
<span class="keyword-directive" style="color: #0000e6;">int</span> sInt = Integer.parseInt(s);
System.out.println(sInt);
<span class="comment" style="color: #969696;">// output:</span>
<span class="comment" style="color: #969696;">// 23</span>
}
}</pre>Unknownnoreply@blogger.com0