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Created by Dr. Xi on November 11, 2011 10:05:22    Last update: November 11, 2011 10:12:01
This is an HTML image tag filter using Java regex. It takes a string, finds the img tags, replaces the src attribute with one provided by the filter, then adds a class name to the class attribute. import java.util.regex.*; import java.io.*; ... Test file: <div id="HTML snippet"> <img src="img/big/txt-m...
Created by alfa on June 07, 2011 11:34:26    Last update: June 07, 2011 11:36:37
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...
Created by alfa on June 02, 2011 13:04:18    Last update: June 02, 2011 13:04:18
Some javap usage examples. Start from HelloWorld.java : @Deprecated public class HelloWorld { pu... javap -c HelloWorld outputs: Compiled from "HelloWorld.java" public class He... javap -v HelloWorld outputs ( -v for verbose mode): Compiled from "HelloWorld.java" 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 freyo on April 12, 2011 15:13:32    Last update: May 03, 2011 15:20:55
Create new project $ tools/android create project \ > --package co... Edit res/values/string.xml , add strings for the main screen. <?xml version="1.0" encoding="utf-8"?> <resourc... Add widgets to main layout ( res/layout/main.xml ). <?xml version="1.0" encoding="utf-8"?> <LinearL... Edit src/com/android/apkinfo/GetAPKPermissions.java and change contents to: package com.android.apkinfo; import android... Install the debug package to the emulator: ant install The screen should look like: Add display permissions activity. Start by creating a new layout res/layout/display_permissions.xml : <?xml version="1.0" encoding="utf-8"?> <LinearL... Add the strings used by the new Activity ( res/values/strings.xml ): <?xml version="1.0" encoding="utf-8"?> <resourc... Add the Display Permissions Activity ( src/com/android/apkinfo/DisplayPermissions.java ): package com.android.apkinfo; import android... Change src/com/android/apkinfo/GetAPKPermissions.java to invoke the Display Permissions Activity: package com.android.apkinfo; import android... Declare Display Permissions Activity in AndroidManifest.xml : <?xml version="1.0" encoding="utf-8"?> <manifes......
Created by Fang on April 01, 2010 22:24:58    Last update: April 02, 2010 02:49:38
In this note I'll show you how to create and package a JSP custom tag. The purpose of this tag is to display a random splash image for a home page, among a set of images. We should be able to add or delete candidate splash images from the WAR archive without the need to change the JSP. This is the intended use of the tag: <%@ taglib uri="http://custom.tag.com/demo" prefix... In the above example you provide a set of images named splash*.png (e.g., splash1.png, spalsh2.png, ...), and the tag will pick a random one to display when the JSP is rendered. Let's get started. I'll use Maven for this purpose. Create the standard Maven directory structure ./pom.xml ./src ./src/main ./src/main/jav... pom.xml <project xmlns="http://maven.apache.org/POM/4.0.0"... SplashTag.java package tagdemo; import java.util.ArrayList......
Created by Dr. Xi on January 29, 2010 22:07:44    Last update: January 29, 2010 22:07:44
This class demonstrates how to read a binary file in Java. This is the Java version of cat , probably one of the first programs you ever use on a *NIX platform. import java.io.*; public class JavaCat { ...
Created by Dr. Xi on November 19, 2008 00:22:27    Last update: January 07, 2010 23:00:36
There is a open source project named [ini4j] for processing Windows .ini configuration files. However, I found it an overkill for my purposes. So here is my simple implementation of a .ini parser. It mimics the standard java.util.Properties class with enhancements to get and set properties by section name. There are only a few simple rules: Leading and trailing spaces are trimmed from section names, property names and property values. Section names are enclosed between [ and ] . Properties following a section header belong to that section Properties defined before the appearance of any section headers are considered global properties and should be set and get with no section names. You can use either equal sign ( = ) or colon ( : )...