Java Personal Tips

Eclipse RCP - Create menu with command

2011-09-02T06:49:00.000-07:00

Tutorial 1 : Create menu with command

Step 1:
Open manifest file MANIFEST.MF

Step 2:
Open tab Extensions in order to use the existed plug-in

Step 3:
Click add button and chose commands plug-in

Step 4:
Define command handler by clicking on default Handler

Step 5
Create menu and associate menu with command

Step 6
Right click to plugin org.eclipse.ui.menus, select New -> menuContribution
Fill the menu contribution

Step 7
Right click on menu contribution and click on popup menu item "Menu"

Step 8
Right click on menu and select New--> Command

Post/Redirect/Get Pattern with SEAM === Pass parameters to next page with h:commandButton

2011-08-29T10:04:00.001-07:00

Post/Redirect/Get (PRG) is a common design pattern for web developers to help avoid certain duplicate form submissions and allow user agents to behave more intuitively with bookmarks and the refresh button.

Problems

Solutions

With seam
h:commandButton also follows this pattern. When user clicks on h:commandButton, it will automatically send http post request to server. At the phase render response in JSF life cycle, it will send http get to browser to render page. Hence, to pass a parameter to next page after user clicks on h:commandButton, seam can help us to do this task very easily

Page1: which has the command button

<h:commandButton action="execute">
</h:commandButton>

Page1.page.xml
cThe navigation rule will tell seam that whenever render response (page 2), it will pass param1 to page2. When render response, seam follow Post/Redirect/Get, it means that seam send get request to server to render page 2

For page 2, to receive the param which passed from page 1, we just need to declare all params needed in page2.page.xml

page2.page.xml

<param name="param1" value=#{bean2.param1} />
<navigation>
</navigation>

Grid in struts 2: Using jquery

2010-02-13T06:58:00.000-08:00

Define grid.jsp contain


<head>
<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
<title>Insert title here</title>
<sj:head useJqGridPlugin="true" jqueryui="true" jquerytheme="redmond" />
</head>

<body>

<s:url id="remoteurl" action="actionReturnJSON" />
<sj:grid id="gridtable" caption="Customer Examples" dataType="json"
 href="%{remoteurl}" 
 pager="true" 
 gridModel="gridModel"
 rowList="10,15,20" 
 rowNum="15" 
 rownumbers="true"
 filter="true"
 multiselect="true"
 navigator="true"
 viewrecords="true">
 <sj:gridColumn name="id" index="id" title="ID" formatter="integer"
  sortable="false" />
 <sj:gridColumn name="name" index="name" title="Name" sortable="true" />
 <sj:gridColumn name="country" index="country" title="Country"
  sortable="false" />
 <sj:gridColumn name="city" index="city" title="City" sortable="false" />
 <sj:gridColumn name="creditLimit" index="creditLimit"
  title="Credit Limit" formatter="currency" sortable="false" />
</sj:grid>
</body>

Use javsscript to change div content

2009-12-11T06:53:00.000-08:00


<html>
<head>
<script language="JavaScript">
function changeContent(divname) {
 document.getElementById(divname).innerHTML=
"Your Content Here!<br><b>HTML Allowed!</b>";
}
</script>
</head>
<body>
<div id="yourDiv">Initial Content</div><br>
<input type="button" value="CHANGE!" 
                   onClick="changeContent('yourDiv')">
</body>
</html>

Java: System Properties

2009-07-14T10:00:00.000-07:00

Java: System Properties

From System Properties you can find information about the operating system, the user, and the version of Java.

The property names (keys) and values are stored in a Properties structure. (See Properties). A Properties object can also be used to store your own program properties in a file.
Getting the System Properties

Typically you get one property at a time by supplying the key in a call to System.getProperty().

* String System.getProperty(String key)
Returns the value of property key as a String.
* String System.getProperty(String key, String default)
Returns the value of property key as a string, or default if the property did not exist.
* Properties System.getProperties()
Returns a Properties object which has the value of all the properties. There are several ways to work with this object; see below for one example.

Example

String userDir = System.getProperty("user.dir");

A list of system properties

Here are the properties that displayed on my system.

awt.toolkit=sun.awt.windows.WToolkit
file.encoding=Cp1252
file.encoding.pkg=sun.io
file.separator=\
java.awt.graphicsenv=sun.awt.Win32GraphicsEnvironment
java.awt.printerjob=sun.awt.windows.WPrinterJob
java.class.path=.;c:\classpath\com.fredswartz.utilities.jar;c:\classpath\TableLayout.jar;c:\classpath\swixml.jar;c:\classpath\jdom.jar;c:\classpath\pmd-1.8\lib\pmd-1.8.jar;C:\classpath\pmd-1.8\lib\jaxen-core-1.0-fcs.jar;C:\classpath\com.fredswartz.guiUtils.jar;C:\classpath\com.fredswartz.fmt-0.7.jar;C:\Program Files\IBM\Cloudscape_10.0\lib\derby.jar
java.class.version=49.0
java.endorsed.dirs=C:\Program Files\Java\jdk1.5.0_01\jre\lib\endorsed
java.ext.dirs=C:\Program Files\Java\jdk1.5.0_01\jre\lib\ext
java.home=C:\Program Files\Java\jdk1.5.0_01\jre
java.io.tmpdir=C:\DOCUME~1\Owner\LOCALS~1\Temp\
java.library.path=C:\Program Files\Java\jdk1.5.0_01\bin;.;C:\WINDOWS\system32;C:\WINDOWS;C:\WINDOWS\system32;C:\WINDOWS;C:\WINDOWS\System32\Wbem;c:\Python22;C:\Program Files\PC-Doctor for Windows\services;c:\ant\bin;c:\Program Files\Java\jdk\bin;c:\Program Files\Java\jdk\jre\javaws;C:\Program Files\Sybase\Adaptive Server Anywhere 6.0\win32;c:\classpath\jcsc/bin;c:\classpath\jcsc\bin;C:\Program Files\Microsoft Visual Studio\Common\Tools\WinNT;C:\Program Files\Microsoft Visual Studio\Common\MSDev98\Bin;C:\Program Files\Microsoft Visual Studio\Common\Tools;C:\Program Files\Microsoft Visual Studio\VC98\bin
java.runtime.name=Java(TM) 2 Runtime Environment, Standard Edition
java.runtime.version=1.5.0_01-b08
java.specification.name=Java Platform API Specification
java.specification.vendor=Sun Microsystems Inc.
java.specification.version=1.5
java.vendor=Sun Microsystems Inc.
java.vendor.url=http://java.sun.com/
java.vendor.url.bug=http://java.sun.com/cgi-bin/bugreport.cgi
java.version=1.5.0_01
java.vm.info=mixed mode, sharing
java.vm.name=Java HotSpot(TM) Client VM
java.vm.specification.name=Java Virtual Machine Specification
java.vm.specification.vendor=Sun Microsystems Inc.
java.vm.specification.version=1.0
java.vm.vendor=Sun Microsystems Inc.
java.vm.version=1.5.0_01-b08
line.separator=

os.arch=x86
os.name=Windows XP
os.version=5.1
path.separator=;
sun.arch.data.model=32
sun.boot.class.path=C:\Program Files\Java\jdk1.5.0_01\jre\lib\rt.jar;C:\Program Files\Java\jdk1.5.0_01\jre\lib\i18n.jar;C:\Program Files\Java\jdk1.5.0_01\jre\lib\sunrsasign.jar;C:\Program Files\Java\jdk1.5.0_01\jre\lib\jsse.jar;C:\Program Files\Java\jdk1.5.0_01\jre\lib\jce.jar;C:\Program Files\Java\jdk1.5.0_01\jre\lib\charsets.jar;C:\Program Files\Java\jdk1.5.0_01\jre\classes
sun.boot.library.path=C:\Program Files\Java\jdk1.5.0_01\jre\bin
sun.cpu.endian=little
sun.cpu.isalist=pentium_pro+mmx pentium_pro pentium+mmx pentium i486 i386 i86
sun.desktop=windows
sun.io.unicode.encoding=UnicodeLittle
sun.jnu.encoding=Cp1252
sun.management.compiler=HotSpot Client Compiler
sun.os.patch.level=Service Pack 2
user.country=US
user.dir=C:\0www-workingnotes\notes-java-working\io\30properties_and_preferences\40sysprops\SysPropList
user.home=C:\Documents and Settings\Owner
user.language=en
user.name=Owner
user.timezone=
user.variant=

Debug Java applications remotely with Eclipse

2009-07-14T09:26:00.000-07:00

We are ready to start debugging an application remotely. Let's do it step by step:

1. Create a Java project with a simple class: We create a simple class for debugging purpose. Listing 1 shows the sample code.

Listing 1. Sample code for debugging

package com.ibm.developerWorks.debugtest;

public class test {

public static void main(String[] args) {
 System.out.println("This is a test.");
}
}
2. Set a breakpoint
3. Debug the application remotely

Copy the JAR file to the appropriate location on the remote computer, or even the same machine, invoke the debug server, and then attach a client to it. The simple Java application can act as a debug server or client. Depending on the configuration, you can choose either Socket Attach or Socket Listen connection type in Eclipse. Learn how to run the application as a server or client in the following two sections.

3.1 The simple Java application can act as a debug server

java -Xdebug -Xrunjdwp:transport=dt_socket,server=y,address="8000" -jar
  test.jar

Set the Eclipse is debug client

3.2 Eclipse is debug server

Run the client as

java -Xdebug -Xrunjdwp:transport=dt_socket,address=127.0.0.1:8000,suspend=y
        -jar test.jar

This article illustrated how to use the Eclipse built-in remote Java
application configuration type to perform application debugging
remotely. It introduced how to set up a Java application to invoke
remote debugging and helped you understand the connectors Eclipse
provides. Finally, you learned how to apply this technology to your
projects.

Changing JBoss 5 port

2009-06-06T08:23:00.000-07:00

+ Increments the default port assignments by 100 if using the 
ports-01 setting:
run -Djboss.service.binding.set="ports-01"

+ Increments the default port assignments by 200 if using the 
ports-02 setting:
run -Djboss.service.binding.set="ports-02"

+ Increments the default port assignments by 300 if using the 
ports-03 setting:
run -Djboss.service.binding.set="ports-03"

+ Increments the default port assignments by 400 if using the
ports-04 setting:
run -Djboss.service.binding.set="ports-04"