To implement a JSP custom tag with dynamic attributes (for example, to pass-thru arbitrary attributes not handled by the JSP tag): Set the dynamic-attributes element to true in the TLD: <tag> <name>mark</name> <tag-class>c... The tag handler must implement javax.servlet.jsp.tagext.DynamicAttributes : package com.example.jsp; import java.io.*; ...

The improved custom taglib works with existing facelet ui taglibs. For example: <ui:param name="theName" value="John"/> <my:hel... produces the expected output. However, a problem exists with the ui:repeat tag: <h3>With ui:repeat</h3> <ui:repeat var="theName... When tested with a URL like: http://localhost:8080/facelet-demo/?name=Zack&name... the raw EL prints out the correct names, but my custom tag substitutes empty string for theName2 ! In theory, the response is rendered in the Render Response phase, way after the Apply Request Values phase, actual values should be available to EL. The answer to this anomaly turned out to be very deep ! Yes, right there in the code! I would consider this a bug in facelets implementation, but the JSF spec did not tell what the expected behavior should be. In my custom...

In the test for the simple taglib example , I used a literal string for the name attribute: <my:hello name="Jack"/> What happens if the name attribute contains EL expresson? For example: <my:hello name="#{param['name']}"/> If EL works, the tag should take the value of the " name " request parameter and print it out. But the tag as implemented in the simple taglib example prints the literal string: Hello #{param['name']}! I am FaceletTag. In order to make a tag to recognize EL, we have to use TagAttribute.getValue(FaceletContext ctx) instead of TagAttribute.getValue() . The latter returns the literal value of the attribute. The HelloTagHandler should be changed to: package com.example; import java.io.IOExcep... Rebuild the taglib and test with a URL like this: http://localhost:8080/facelet-test/?name=Jack The tag will print:...

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/App.java src/test/java/com/example/AppTest.java This project should be able to build with: mvn package Add facelet API dependencies to pom.xml : <project xmlns="http://maven.apache.org/POM/4.... The compiler plugin section is optional. Remove src/main/java/com/example/App.java , create a new Java class as the facelet Tag Handler ( HelloTagHandler.java ): package com.example; import java.io.IOExcep... 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...

This is an Android app that dumps any binarized xml file as plain text - to the sdcard on the device or emulator. build.xml : <?xml version="1.0" encoding="UTF-8"?> <project... AndroidManifest.xml <?xml version="1.0" encoding="utf-8"?> <man... res/layout/main.xml <?xml version="1.0" encoding="utf-8"?> <Lin... res/values/strings.xml : <?xml version="1.0" encoding="utf-8"?> <res... src/com/android/xmltool/DumpXml.java package com.android.xmltool; import java.ut... Screenshot Pre-built APK can be downloaded from: http://code.google.com/p/android-binxml-dump/

This is an example that uses dynamic proxies to trace method calls (in logging) and print out elapsed times for them. Because dynamic proxies can only be generated for interfaces, the service classes must be implemented with interface-implementation pairs. Create services A and B. A.java : public interface A { public void service1()... AImpl.java : import java.util.Random; public class AImpl... B.java : public interface B { public void service1()... BImpl.java : public class BImpl implements B { public vo... The call trace proxy: import java.lang.reflect.*; class TraceProx... The performance proxy: import java.lang.reflect.*; class Performan... The service factory: import java.lang.reflect.*; public class Se... The test class: public class Test { public static void main... The output: Entering AImpl.service1 Entering BImpl.service1... The above example has no information...

In short, use the PackageManager class to get the PackageInfo : PackageInfo pkgInfo = getPackageManager().getP... To build an APK, make these changes to the greetings app : Change the layout to ( res/layout/main.xml ): <?xml version="1.0" encoding="utf-8"?> <LinearL... Change the string values ( res/values/strings.xml ): <?xml version="1.0" encoding="utf-8"?> <resourc... Update AndroidManifest.xml : <?xml version="1.0" encoding="utf-8"?> <manifes... Create a new Java class src/com/android/appinfo/GetAppVersion.java : package com.android.appinfo; import android... Edit build.xml , change project name to "AppInfo": <?xml version="1.0" encoding="UTF-8"?> <project... Install to emulator: ant install Screenshot:

Format Name Description PKCS #7 Cryptographic Message Syntax Standard A PKCS #7 file can be used to store certificates, which is a SignedData structure without data (just the certificates). The file name extension is usually .p7b , .p7c PKCS #8 Private-Key Information Syntax Standard. Used to carry private certificate keypairs (encrypted or unencrypted). PKCS #12 Personal Information Exchange Syntax Standard. Defines a file format commonly used to store private keys with accompanying public key certificates, protected with a password-based symmetric key. It is the successor to PFX from Microsoft. DER Distinguished Encoding Rules A binary format for keys or certificates. It is a message transfer syntax specified by the ITU in X.690. PEM Privacy Enhanced Mail Base64 encoded DER certificates or keys, with additional header...

A task that a Java developer does so frequently is to find out where a certain class can be found - to resolve compilation errors, classpath issues, or version conflicts of the same class introduced by multiple class loaders. A long while back I wrote a simple Perl script to perform the task. Later I was informed that there are Swing based Jar Browser and Jars Browser . Then, there are a couple of shell one-liners: # one liner 1 find -name "*.jar" -print0 | xarg... But all of them share the same problem: if a class is in a jar nested in another jar, it cannot be found. Such is the case for a class inside a jar under the WEB-INF/lib directory of a...

This is the task: your client wants to know how the web application is used. That is pretty easy. A plethora of commercial tools or any of the free log analysis tools such as analog and AWStats would fit the bill. But here's the catch: they want to know not only what pages are visited by how many people and when, but also who logged in and did what. Your application is using form based authentication and therefore, everyone is anonymous in the web access log. What to do? This is a servlet filter that generates a web access log with authenticated user info that can be fed to log analysis tools such as analog and AWStats . Filter code (the output format is Apache...