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Created by Fang on December 06, 2011 19:03:25    Last update: December 07, 2011 08:54:11
Our custom tag, as implemented in the previous note , is broken when a template is used. Create a template file ( home-template.xhtml ): <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Stric... and a test page that uses it ( home.xhtml ): <?xml version="1.0" encoding="UTF-8"?> <ui:comp... Then request the page with URL: http://localhost:8080/facelet-demo/home.jsf?name=Jack . You'll find that our hello tag works inside ui:repeat but fails to get the value defined by ui:param ! What's the problem? Our hello tag implementation evaluated the EL with the wrong EL context! This is the corrected implementation: package com.example; import
Created by Fang on November 10, 2011 09:26:12    Last update: November 10, 2011 09:26:12
Syntax highlighted XML schema for JSF 2.0 Application Configuration Resource File ( faces-config.xml ). Almost 3000 lines! <?xml version="1.0" encoding="UTF-8"?> <xsd:sch...
Created by Fang on November 03, 2011 19:47:38    Last update: November 08, 2011 20:24:47
This is a step-by-step example to create a really simple facelet taglib (in JSF 2 with Maven). Create a simple Maven project with: mvn archetype:create -DgroupId=com.example -Dartif... Three files are created as a result: pom.xml src/main/java/com/example/ src/test/java/com/example/ This project should be able to build with: mvn package Add facelet API dependencies to pom.xml : <project xmlns=" The compiler plugin section is optional. Remove src/main/java/com/example/ , create a new Java class as the facelet Tag Handler ( ): package com.example; import This tag handler simply prints a "Hello" message. Create facelet tag declaration file src/main/resources/META-INF/hello.taglib.xml : <?xml version="1.0" encoding="UTF-8"?> <facelet... Build the JAR with mvn clean package Optionally, install it to the local repository: mvn install To use the taglib, simply drop the...
Created by Fang on September 07, 2009 20:44:15    Last update: November 03, 2011 14:43:19
Step 1: Repackage a web app as EAR A Java EE application is a multimodule Maven project. At the very least you'll need to package a WAR and an EAR. To get started, I'll simply re-package the simple webapp as an EAR. Create a directory named javaee-app Copy the webapp from here to javaee-app . Rename struts1app to webapp . Create pom.xml under javaee-app : <project> <modelVersion>4.0.0</modelVersion>... Create a directory named ear under javaee-app . Create pom.xml under ear : <project> <modelVersion>4.0.0</modelVersion>... Modify pom.xml in the webapp directory so that it looks like this: <project> <modelVersion>4.0.0</modelVersion> ... Build with " mvn package " in the javaee-app directory. You can see that ear-1.0.ear is successfully generated in javaee-app/ear/target . Maven successfully resolves dependencies between the sub-projects....
Created by Fang on October 22, 2011 19:51:05    Last update: October 22, 2011 20:31:48
I built a very basic JSF application and deployed to Tomcat 7.0.22, but it failed with this error: Caused by: java.lang.ClassFormatError: Absent Code... That looks weird and I wasn't able to find a sensible explanation! So I copied the jsf-api-2.1.jar , which was downloaded from the Maven repository by Maven, into a temp folder. And tested it with this simple program: public class ClassFormatErrorTest { public ... I also copied servlet-api.jar from Tomcat's lib folder to the temp folder. Sure enough it failed with the same error: C:\tmp>java -cp .;jsf-api-2.1.jar;servlet-api.jar ... But when I replaced the javax.faces.webapp.FacesServlet class with one I compiled from source, the error disappears! Conclusions: The jar file jsf-api-2.1.jar from Maven repository is good for compilation only (cannot be used...
Created by Dr. Xi on June 16, 2011 14:23:44    Last update: June 16, 2011 14:25:04
This example shows how a service implementation can be loaded with a URLClassLoader . The files. : public interface HelloService { public void... : public class HelloServiceImpl implements HelloServ... uses URLClassLoader to load the service implementation: import*; import*; pub... : import*; import*; pub... Create a runnable client jar: C:\>jar -cfe client.jar Test Test.class ServiceFac... Create a service jar: jar -cf service.jar HelloServiceImpl.class Test: C:\>java -jar client.jar Class Loader: Extra Note: : JDK7 added a method URLClassLoader.close() , so that a URLClassLoader can be discarded, and a new one created to load a new implementation.
Created by alfa on June 02, 2011 13:04:18    Last update: June 02, 2011 13:04:18
Some javap usage examples. Start from : @Deprecated public class HelloWorld { pu... javap -c HelloWorld outputs: Compiled from "" public class He... javap -v HelloWorld outputs ( -v for verbose mode): Compiled from "" public class He... The output consists of: " Compiled from... " header Class attributes. For the HelloWorld example, there are two: SourceFile and Deprecated . Minor and major class file version Constant pool Disassembled code LineNumberTable for debugging purposes. javap by default only prints package/protected/public members. To display all members including private, use the -p switch. javap -v -p HelloWorld
Created by Dr. Xi on March 30, 2011 13:43:05    Last update: March 30, 2011 13:45:27
Method 1 - use javap with verbose flag: $ javap HelloWorld -verbose | head Compiled fro... Method 2 - use a utility class: import*; import java.nio.ByteBuffer; ... According to the VM Spec , a Java class file has this structure: ClassFile { u4 magic; ...
Created by Dr. Xi on March 02, 2011 11:39:18    Last update: March 09, 2011 12:19:30
Some peculiarities about Java PrintWriter: PrintWriter never throws any exceptions. From JavaDoc : Methods in this class never throw I/O exceptions, although some of its constructors may. The client may inquire as to whether any errors have occurred by invoking checkError(). When error occurs, you'll never know anything more than that it occured, because checkError returns boolean. When a character is out of the range of the character encoding of the PrintWriter, it prints a question mark (?). But this is not an error. Test code: import*; public class TestPrintWri... Latin1 test result: java TestPrintWriter iso-8859-1 | od -bc 000000... UTF-8 test result: java TestPrintWriter utf-8 | od -bc 0000000 141... Also, the constructor throws a FileNotFoundException when you try to write to a...
Created by nogeek on November 04, 2010 20:00:15    Last update: November 05, 2010 14:38:43
Following are some bugs in the Xalan jar shipped with JBoss 5.1.0 GA and JBoss 6.0. The Xalan jar file is located in jboss-5.1.0.GA/lib/endorsed ( %JBOSS_HOME%/common/lib for JBoss 6.0). Test xml: <?xml version="1.0" encoding="ISO-8859-1"?> ... Test xsl: <?xml version="1.0" encoding="ISO-8859-1"?> <xs... XSLT Java code: import org.w3c.dom.*; import javax.xml.parsers.... import java.util.Date; public class DateUti... XSLT output: Transformer Factory class: class org.apache.xalan.... Apparently, the output is wrong. The string "A test event" should not have been displayed.
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