Referring 3rd party Jars within your Jar /lib : MANIFEST.mf Class-Path

As per my current understanding, you cannot refer any third party utility Jars which you placed in your apps /lib folder, when you export it as a Jar. 

Say yourJar.jar has lib/log4j.jar.  But your main class cannot load the log4j classes

http://www.velocityreviews.com/forums/t130458-executable-jar-classpath-problem.html 

The workaround for this situation: Place those utility/thrid party Jars in the same directory or inner directories, where your Jar is placed and making sure that that relative path is mentioned in the Manifest.mf Class-path Header.

<!-- This build script will help you build your own Jar, with utility Jars exported with

and all those Jars added to the MANIFEST.mf Class-Path header

-->

<project

name="buildJar" default="build-jar" basedir=".">

<!-- Add all the jar files in lib folder to the class path -->

<path id="build.classpath">

<fileset dir="${basedir}/">

<include name="lib/*.jar" />

</fileset>

</path>

<!-- Copy all Jars name to the Class-Path; keep an eye on the SPACE seperator -->

<pathconvert property="project.manifest.classpath" pathsep=" lib/">

<path refid="build.classpath" />

<mapper>

<chainedmapper>

<flattenmapper />

<globmapper from="*.jar" to="*.jar" />

</chainedmapper>

</mapper>

</pathconvert>

<target name="clean">

<delete dir="bin" />

<mkdir dir="bin/lib" />

<delete dir="build" />

<mkdir dir="build" />

</target>

<target name="copy-inner-jar-files">

<copy todir="bin/lib" includeemptydirs="false">

<fileset dir="lib" includes="*.jar" />

</copy>

</target>

<target name="copy-non-java-files">

<copy todir="bin" includeemptydirs="false">

<fileset dir="src" includes="**/*" />

</copy>

</target>

<target name="compile-jar-classes" depends="clean,copy-non-java-files, copy-inner-jar-files">

<javac srcdir="src" destdir="bin" classpathref="build.classpath" />

</target>

<target name="build-jar" depends="compile-jar-classes" >

<jar basedir="bin" jarfile="${basedir}/build/MyJar.jar">

<fileset dir="build" />

<manifest>

<attribute name="Main-Class" value="com.sree.test.jar.MyInnerJarTesterMain" />

<!-- <attribute name="Class-Path" value=" . lib/junit-4.10.jar lib/log4j.jar lib/ojdbc14.jar" /> -->

<attribute name="Class-Path" value=". lib/${project.manifest.classpath}" />

</manifest>

</jar>

</target>

>jar -xf MyJar.jar lib

-->

<!-- To take out just the lib/ directory jars out to the same directory as this JAR use below command</project>

<?xml version="1.0"?>

The reRender property of a4j:commandButton or a4j:commandLink can be used to reRender other JSF - richFaces components.

Steps:
1) Mention the component IDs to be reRendered in the "reRnder" attribute of the a4j:commandButton, separated by comma. This will make those components get reRendered on button click. 

2) If its a4j:mediaOutput step 1 will not make the image to be refreshed. Reason being, the mediaOutput tag will cache the image until there is a change in the "value" attribute.

So even if you don't want to "value" attribute, use it and bind it with a method that returns random value (say random Number or time)

Sample code is given below:

<h:form >
       <a4j:commandButton value="RefreshImage"
              action="#{testBean.clickButtonAction}"
              reRnder="outputImage,output"/>

<rich:Panel>
<a4j:outputPanel id="outputImage">

<a4j:mediaOutput createContent="#{graphBean.paint}" value="#{graphBean.time}" mimeType="image/jpeg" id="output" element="img" cacheable="false" session="false"/>
</a4j:outputPanel>
</rich:Panel>

</h:form>

Difference between JDK1.4.2, JDK 1.5.0 and JDK1.6 JDK 1.0 (january 23, 1996) oak
- Initial release

JDK 1.1 (february 19, 1997)

- Retooling of the AWT event model
- Inner classes added to the language
- JavaBeans
- JDBC
- RMI
J2SE 1.2 (December 8, 1998) playground

This and subsequent releases through J2SE 5.0 were rebranded retrospectively Java 2 & version name "J2SE"
(Java 2 platform, Standard edition) replaced JDK to distinguish the base platform from
J2EE (java 2 platform, enterprise edition) and J2ME (java 2 platform, micro edition).

- Strictfp keyword
- Reflection
- Swing api integration into the core classes
- JVM equipped with a jit compiler
- Java plug-in
- Java IDL
- An IDL implementation for corba interoperability
- Collections Framework
J2SE 1.3 (may 8, 2000) kestrel

- Hotspot jvm included
- JavaSound
- JNDI included in core libraries
- Java platform debugger architecture (jpda)
- RMI was modified to support optional compatibility with corba

J2SE 1.4 (february 6, 2002) merlin

- assert keyword
- Regular expressions
- Exception chaining (allows an exception to encapsulate original lower-level exception)
- Internet protocol version 6 (IPV6) support
- Non-blocking nio (new input/output)
- Logging API
- Image i/o api for reading and writing images in formats like jpeg and png
- Integrated XML parser and XSLT processor (JAXP)
- Integrated security and cryptography extensions (JCE, JSSE, JAAS)
- Java web start

J2SE 5.0 (september 30, 2004) tiger [originally numbered 1.5]


 Sun replaced the name "J2SE" with java se and dropped the ".0" from the version number.
Beta versions were released in february and june 2006, leading up to a final release that occurred on december 11, 2006.
The current revision is update 14 which was released in may 2009.

- Support for older win9x versions dropped.
- Scripting lang support: Generic API for integration with scripting languages, & built-in mozilla javascript rhino integration
- Dramatic performance improvements for the core platform, and swing.
- Improved web service support through JAX-WS JDBC 4.0 support
- Java compiler API: an API allowing a java program to select and invoke a java compiler programmatically.
- Upgrade of JAXB to version 2.0: including integration of a stax parser.
- Support for pluggable annotations
- Many GUI improvements, such as integration of swingworker in the API, table sorting and filtering, and true swing double-buffering (eliminating the gray-area effect).

Java se 6 update 10


This release includes the highly anticipated 64-bit java plug-in (for 64-bit browsers only), windows server 2008 support,
and performance improvements of java and JAVAFX applications.
Features and Enhancements JDK Documentation
Java Platform, Standard Edition 6 is a major feature release. The following list highlights many of the significant features and enhancements in Java SE 6 since the prior major release, J2SE 5.0. It is followed by a detailed table with links to related bugs, enhancements, and JSRs.

Note, this web page relates to the Release Candidate milestone for Java SE 6. Its related Umbrella JSR 270 does not itself define specific features. Instead it enumerates features defined in other JSRs or through the concurrent maintenance review of the Java SE platform specification. The final release is expected to include all JSR 270 features, although it is possible for an approved feature to be dropped.

Refer also to: Java Platform, Standard Edition Differences between 5.0 fcs and 6 Beta .

Highlights of Technology Changes in Java SE 6 Choose a technology for links to further information.
Collections Framework
Deployment (Java Web Start and Java Plug-in)
Drag and Drop
Instrumentation
Internationalization Support
I/O Support
JAR (Java Archive Files) - An annotated list of changes between the 5.0 and 6.0 releases to APIs, the jar command, and the jar/zip implementation.
Java Web Start
Java DB 10.2 JDBC4 Early Access

The $JAVA_HOME/db subdirectory contains class libraries for Java DB, Sun Microsystems's distribution of the Apache Derby database technology.
For information on Java DB, see Java DB.
For information on Derby, see: Apache Derby.
For documentation on this version of Java DB, see Java DB - Reference.
For a description of the capabilities of this version of Java DB, see the release notes in the $JAVA_HOME/db subdirectory.
This Early Access version of Java DB is built from Apache Derby 10.2.1.7 source code (revision 453926) using JDK 6 JDBC 4 APIs to build JDBC 4 driver code.
Comments regarding this version of Java DB can be sent to javadb-ea@sun.com.

DISCLAIMER: THIS IS EARLY ACCESS SOFTWARE AND COMES WITH NO WARRANTIES OR SUPPORT. IT IS PROVIDED "AS IS". IT IS NOT FOR PRODUCTION USE.

JMX (Java Management Extensions) - A list of JMX API changes between the J2SE 5.0 and Java SE 6 releases.
JPDA (Java Platform Debugger Architecture)
JVM TI (Java Virtual Machine Tool Interface)
lang and util Packages
Monitoring and Management for the Java Platform
JConsole is Officially Supported in Java SE 6
Networking Features
Performance
Reflection
RMI (Remote Method Invocation)
Scripting
Security
Serialization of Objects
Swing
VM (Java Virtual Machine)

Detailed Table of Technology Changes in Java SE 6

Items are ordered by area/component. The first column indicates the scope of a change:

jsr – A larger feature or feature set having its own Java Specification Request
api – A smaller feature that adds new Java APIs (application programming interfaces)
imp – An implementation enhancement that does not involve new APIs, for example, a performance improvement

@courtesy : java-forums.orgA major enhancement in terms of end-user usability.
- Java Deployment Toolkit, a set of javascript functions to ease the deployment of applets and java web start applications.
- Java Kernel, a small installer including only the most commonly used jre classes. Enhanced updater.
- Enhanced versioning and pack200 support: server-side support is no longer required.
- Java quick starter, to improve cold start-up time.
- Improved performance of java2D graphics primitives on windows, using direct3D and hardware acceleration.
- A new Swing look and feel called NIMBUS and based on synth.
- Next-generation java plug-in: applets now run in a separate process and support many features of web start applications.
Java se 6 update 12 - Generics: provides compile-time (static) type safety for collections and eliminates the need for most typecasts (type conversion).
- Metadata: also called annotations; allows language constructs such as classes and methods to be tagged with additional data, which can then be processed by metadata-aware utilities.
- Autoboxing/unboxing: automatic conversions between primitive types (such as int) and primitive wrapper classes (such as integer).
- Enumerations: the enum keyword creates a typesafe, ordered list of values (such as day.monday, day.tuesday, etc.). Previously this could only be achieved by non-typesafe constant integers or manually constructed classes (typesafe enum pattern).
- Swing: new skinnable look and feel, called synth.
- Var args: the last parameter of a method can now be declared using a type name followed by three dots (e.g. Void drawtext(string... Lines)). In the calling code any number of parameters of that type can be used and they are then placed in an array to be passed to the method, or alternatively the calling code can pass an array of that type.
- Enhanced for each loop: the for loop syntax is extended with special syntax for iterating over each member of either an array or any iterable, such as the standard collection classesfix the previously broken semantics of the java memory model, which defines how threads interact through memory.
- Automatic stub generation for rmi objects.
- Static imports concurrency utilities in package java.util.concurrent.
- Scanner class for parsing data from various input streams and buffers.
- Assertions- StringBuilder class (in java.lang package)
- Annotations

Java SE 6 (december 11, 2006) mustang

Spring-Beans.DTD / Spring-Webflow.DTD - XML validation Issue and Solution

This is the issue: The file cannot be validated as the XML Schema "http://www.springframework.org/dtd/spring-beans-2.0.dtd" that is specified as describing the syntax of the file cannot be located.

Solution: Use “XML Catalog”

Step 1 : Add XML Catalog in Eclipse: XML à XML Catalog à User Specified Entries à New

Location:             org\springframework\beans\factory\xml\spring-beans-2.0.dtd in jar file D:\work\Learn\SpringExample1\WebContent\WEB-INF\lib\org.springframework.beans-3.1.1.RELEASE.jar

URI:                        jar:file:///D:/work/Learn/SpringExample1/WebContent/WEB-INF/lib/org.springframework.beans-3.1.1.RELEASE.jar!/org/springframework/beans/factory/xml/spring-beans-2.0.dtd

Key Type:            URI

Key:                       CATALOG-spring-beans-2.0.dtd [or use the generic one ‘-//SPRING//DTD BEAN 2.0//EN’ à you can give any name, but use the same in your XML]

  

Step 2: Use this Catalog Key in your XML. No need to use the DTD path and XSD Schema etc at all. Now you have the auto complete enabled as per the TDD 

Android - Test App : Issues I faced and Solution

It was the first time I an trying with Android ... You might as well face the similar issues for the first time try.

1) Android emulator-arm.exe crashing in Windows XP - Space in SDK HOME
2) Can't see the App even after it got started as per console logs - Unlock

There seems to be 2-3 reasons behind the issues I faced.

1) The SDK directory should not have space in path (folder name). I had installed in 'Program FIles'. Also its better to have all sub directories in the SDK path to be <8 characters.

http://8thstring.blogspot.com/2011/09/android-emulator-armexe-crashing-in.html 

I used a small, no space directory for installing SDK.  The error gone.

2) I was not patient enough to avoid clicking the screen till the app loads completely it seems.

3) I have to unlock the AVD screen to see the app.. I didn't notice that.. :P 

Log4j - Child Logs are written in to Parent Log file (for imported child apps)

Log4j Appender: Child Logs are written in to Parent Log file.

<Just scribbling the factors> ...will be edited later.</>

I created one app (say it as a Job) – a stand alone java with logging features through Log4j. I had my own log4j.proeprties with file Appender and my own log file specified.

This job is extracted as Jar and shared with another app (say it as a scheduler). The scheduler loads this Jar (along with many other jars for different Jobs) dynamically through Class Loader.

It also used log4j for logging purpose.

What happened: The logs by the child apps (jobs) where getting written in to the parent (Scheduler) messed up with parent log statements in the parent log file. The child log file was not having any logs written.

This is a known feature as long as the Classloader loads the child apps to one app.

If you need separate logs, the parent log4j.properties has to define another rootLoagger and that logger has to be used in the child logging purpose.. meaning it has got little dependency or coupling b/w parent and child.

JUnit: Testcase: initializationError : java.lang.NoClassDefFoundError: org/hamcrest/SelfDescribing

When: Tried to run a JUnit TestCase, I got below error.

Error: JUnit Error.NoClassDefFoundError: org/hamcrest/SelfDescribing

Scenario: I was using Junit.jar 4.0 version

Solution: Use the latest JUnit jar – 4.10.

Reason: Some posts says it as due to the log4j version mismatch b/w what is there in junit jar and the one in Ant jar.

Testcase: initializationError took 0 sec 
Caused an ERROR 
org/hamcrest/SelfDescribing 
java.lang.NoClassDefFoundError: org/hamcrest/SelfDescribing 
    at java.lang.ClassLoader.defineClass1(Native Method) 
    at java.lang.ClassLoader.defineClass(Unknown Source) 
    at java.security.SecureClassLoader.defineClass(Unknown Source) 
    at java.net.URLClassLoader.defineClass(Unknown Source) 
    at java.net.URLClassLoader.access$000(Unknown Source) 
    at java.net.URLClassLoader$1.run(Unknown Source) 
    at java.security.AccessController.doPrivileged(Native Method) 
    at java.net.URLClassLoader.findClass(Unknown Source) 
    at java.lang.ClassLoader.loadClass(Unknown Source) 

Refer: http://stackoverflow.com/questions/1171264/ant-junit-noclassdeffounderror