Recent Notes
Displaying keyword search results 1 - 10
Created by Fang on April 16, 2012 13:18:40
Last update: April 16, 2012 13:18:40
Simply call pageContext.setAttribute() to export a variable from within a JSP custom tag:
public class MyCustomVarTag extends TagSupport {
...
The availability of the exported variable can be limited in the TLD:
<tag>
<name>setVar</name>
<tag-class...
The availability scopes are:
Value Availability
NESTED Between the start tag and the end tag.
AT_BEGIN From the start tag until the scope of any enclosing tag. If there’s no enclosing tag, then to the end of the page.
AT_END After the end tag until the scope of any enclosing tag. If there’s no enclosing tag, then to the end of the page.
Created by Fang on April 16, 2012 12:58:35
Last update: April 16, 2012 12:58:35
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.*;
...
Created by Fang on January 28, 2012 13:24:09
Last update: January 28, 2012 13:31:22
This is a simple JSP custom tags library with tag body. Just like the JSF counterpart , it splits a string and repeats the body for each word, i.e., with this markup:
<%@ taglib uri="http://custom.tag.com/demo" prefix...
output:
<html>
<body>
<p>Hello Tigger!</p>
<p>H...
With Maven, this is the directory structure:
./src
./src/main
./src/main/resources
./s...
There are three files to write:
pom.xml :
<project xmlns="http://maven.apache.org/POM/4.0.0"...
src/main/java/tagdemo/IterateTag.java :
package tagdemo;
import java.io.IOException...
src/main/resources/META-INF/demotag.tld :
<?xml version="1.0" encoding="UTF-8"?>
<!DO...
Build with:
mvn clean install
To use it as a dependency in other Maven projects:
<dependency>
<groupId>tag-demo</groupId>
...
Created by Fang on November 22, 2011 10:40:16
Last update: November 22, 2011 10:40:16
This is an example that uses tag handler, UI component and renderer together to support a custom taglib. The main purpose is to show how these components play together.
The tag renders
<ui:param name="extra" value="el interpreted"/>
...
as
<h3>my:foreach</h3>
<ul class="css class" extra...
These are the files:
The tag handler ( src/main/java/com/example/ForeachTagHandler.java ):
package com.example;
import java.util.Map;
...
The UI component ( src/main/java/com/example/UIForeach.java ):
package com.example;
import java.io.IOExcep...
The renderer ( src/main/java/com/example/ForeachRenderer.java ):
package com.example;
import java.io.IOExcep...
Faces config ( src/main/resources/META-INF/faces-config.xml ):
<?xml version="1.0" encoding="UTF-8"?>
<faces-c...
Taglib config ( src/main/resources/META-INF/foreach.taglib.xml ):
<?xml version="1.0" encoding="UTF-8"?>
<facelet...
Created by Fang on November 08, 2011 20:55:00
Last update: November 21, 2011 18:19:44
In the simple taglib example , I used a tag handler class to implement a taglib. This is an example to implement a taglib with a UI component. The purpose is to use a custom tag to split a string and print each part in a separate paragraph, i.e., print
<p>john</p> <p>steve</p> <p>mike</p> with custom tag <my:foreach> : <my:foreach var="who" value="john steve mike"> ... These are the files: pom.xml <project xmlns="http://maven.apache.org/POM/4.0.0"... src/main/java/com/example/UIForeash.java : package com.example; import java.io.IOExcep... src/main/resources/META-INF/faces-config.xml : <?xml version="1.0" encoding="UTF-8"?> <faces-c... src/main/resources/META-INF/foreach.taglib.xml : <?xml version="1.0" encoding="UTF-8"?> <facelet... How to use: Put the JAR file generated by the above project in the WEB-INF/lib folder of the web app. If the web app is a Maven project, just add the taglib project as a dependency:...
Created by alfa on May 27, 2011 11:19:29
Last update: May 31, 2011 07:56:26
This is a utility to convert a string value to one of the primitive type values. It is useful in Java reflection code where the value comes in as a string (e.g., from XML parsing), and the type of the value cannot be decided until runtime.
import java.util.*;
import java.lang.reflect.*;...
Note: This method can be extended to convert string to more complex types by writing a converter for the destination type. For example, to convert string to date:
public class DateConverter {
public static ...
Usage:
Date d = (Date) ConvertUtil.convert("10/12/2010", ...
Created by alfa on May 24, 2011 14:52:53
Last update: May 26, 2011 19:52:12
import java.lang.reflect.Method;
public cla...
Created by alfa on May 24, 2011 15:59:41
Last update: May 24, 2011 15:59:41
Java reflection with Apache beanutils example.
import org.apache.commons.beanutils.MethodUtils;
...
Created by jinx on May 03, 2011 11:43:26
Last update: May 03, 2011 11:43:26
The PHP function strval returns the string value of a variable. It does the same thing as casting a variable to string, or automatic conversion where string is expected.
Conversion rules:
Type String Value
Boolean TRUE '1'
Boolean FALSE '' (empty string)
integer of float string representing the number
Array The string 'Array'
Object Result of __toString() if defined, error otherwise
Resource 'Resource id #n' , where n is a number assigned to the resource.
NULL '' (empty string)
Example:
<?php
set_error_handler(function($errno, $errst...
Results:
bool(true)
---------------------
strval: '1'...
Created by freyo on April 18, 2011 15:08:21
Last update: April 18, 2011 15:12:20
Generate android project
$ ~/android-sdk-linux_86/tools/android create proj...
Create XML file res/xml/books.xml :
<?xml version="1.0"?>
<catalog>
<book id=...
Edit layout ( res/layout/main.xml ):
<?xml version="1.0" encoding="utf-8"?>
<Lin...
Edit code ( src/com/android/xmlres/XMLResource.java ):
package com.android.xmlres;
import java.io....
Change activity label from app_name to booklist ( AndroidManifest.xml ):
<?xml version="1.0" encoding="utf-8"?>
<manifes...
Add value for string resource ( res/values/string.xml ):
<?xml version="1.0" encoding="utf-8"?>
<resourc...
Deploy and test:
ant install
