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Created by Fang on April 16, 2012 13:32:10
Last update: April 16, 2012 13:32:10
There are two steps to create a custom function for JSP:
Declare the function in the TLD:
<?xml version="1.0" encoding="UTF-8" ?>
<taglib...
Implement the function (must be static):
package com.example;
public class UrlTransl...
To use the function:
<%@ taglib uri="http://www.example.com/jsp/tags" p...
Created by Fang on March 30, 2012 10:07:25
Last update: March 30, 2012 10:09:08
After a user resets a password, I want to force the user to change the password before she gets access to secured content. This is usually done with a servlet filter. But with Spring MVC, you can also use a HandlerInterceptor . According to Spring JavaDoc: HandlerInterceptor is basically similar to a Servlet 2.3 Filter, but in contrast to the latter it just allows custom pre-processing with the option of prohibiting the execution of the handler itself, and custom post-processing. Filters are more powerful, for example they allow for exchanging the request and response objects that are handed down the chain. Note that a filter gets configured in web.xml, a HandlerInterceptor in the application context. As a basic guideline, fine-grained handler-related preprocessing tasks are candidates...
Created by Dr. Xi on March 13, 2012 08:46:57
Last update: March 13, 2012 08:46:57
This trick sets HTML base to the root context path of the current webapp:
The short version:
<!DOCTYPE html>
<%@ taglib uri="http://java.sun...
The long version:
<!DOCTYPE html>
<%@ taglib uri="http://java.sun...
Created by meiu on February 09, 2012 09:55:26
Last update: February 09, 2012 09:55:26
In the package explorer pane:
Right click on the folder
Move mouse to Build Path
Select Use as Source Folder
To revert a source folder selection: mouse over Build Path and select Remove from Build Path .
Created by Fang on February 08, 2012 21:15:00
Last update: February 08, 2012 21:15:00
This was the error message:
[ERROR] sun.security.validator.ValidatorExceptio...
The certificate was actually signed by Verisign, but somehow failed to pass Java cert validation.
To resolve the problem:
Download the cert from the server (with RetrieveSSLCert , for example)
Import the certificate into the keystore:
$ keytool -import -trustcacerts -alias myserver -f...
Define MAVEN_OPTS :
$ export MAVEN_OPTS='-Djavax.net.ssl.trustStore=/h...
The quotes must exist for the value of MAVEN_OPTS , and the path must be absolute ( ~/etc/mavenKeyStore.jks does not work).
Created by Fang on January 31, 2012 15:40:34
Last update: January 31, 2012 15:41:28
This is a simple Hello World application with Spring 3 MVC. Like the default Apache HTTPd welcome page, it displays " It works! " when successfully deployed. The sole purpose is to show the minimum elements needed to setup Spring 3 MVC.
I use Maven since it's so much easier than downloading the dependencies manually.
Directory layout:
./src
./src/main
./src/main/webapp
./src/...
pom.xml :
<?xml version="1.0" encoding="UTF-8"?>
<project...
WEB-INF/web.xml :
<?xml version="1.0" encoding="UTF-8"?>
<web-app...
WEB-INF/applicationContext.xml (empty, but needed):
<?xml version="1.0" encoding="UTF-8"?>
<beans x...
WEB-INF/spring-servlet.xml :
<?xml version="1.0" encoding="UTF-8"?>
<beans x...
WEB-INF/jsp/home.jsp :
<!DOCTYPE html>
<html>
<head>
<title>H...
Build with:
mvn clean package
The resulting webapp is target/springmvc.war .
Created by lokf on January 13, 2012 14:10:42
Last update: January 13, 2012 14:10:42
For some reason I don't know writing to files in Android is very complicated and tedious. Here is some code for those who might need it. Apps should write in the SD in the directory /Android/data/package_name/files/ so that it is deleted with the app uninstall. package randomname; import java.io.BufferedOutputStream; import java.io.File; import java.io.FileInputStream; import java.io.FileNotFoundException; import java.io.FileOutputStream; import java.io.FileWriter; import java.io.IOException; import java.io.OutputStream; import java.io.OutputStreamWriter; import java.nio.ByteBuffer; import android.content.Context; import android.os.Environment; import android.util.Log; public class FileIOLibrary { String packageName; boolean mExternalStorageAvailable = false; boolean mExternalStorageWriteable = false; FileIOLibrary(String packageNamep) { this.packageName=packageNamep; } public boolean isExternalStorageAvailable() { updateExternalStorageState(); return mExternalStorageAvailable; } public boolean isExternalStorageWritable() { updateExternalStorageState(); return mExternalStorageWriteable; } /** * writes the current state of SD card to the corresponding variables */ void updateExternalStorageState() {...
Created by Fang on December 09, 2011 11:50:28
Last update: December 09, 2011 11:51:34
Values of Maven properties are accessed with the construct ${...} . Properties come from 5 different sources:
From the environment, for example: ${env.PATH} , ${env.JAVA_HOME} .
From the POM, in the form of ${project.x} . For example: ${project.version} , ${project.groupId} .
From settings.xml , in the form of ${settings.x} . For example: ${settings.offline} , ${settings.interactiveMode} .
From Java system properties, for example: ${java.home} .
Defined within the properties element in the POM. For example ( gae.version ):
<properties>
<gae.version>1.4.2</gae.ve...
Created by Fang on November 12, 2011 21:03:03
Last update: November 12, 2011 21:03:03
Experts may disagree but I found it absolutely stunning that JSF EL does not provide an operator for string concatenation. The Java "+" operator is there for the take. Java, which is a strongly typed compiled language, overloads the "+" operator in such a way that any object can be concatenated with a string. But JSF EL, which definitely isn't as strongly typed as Java, restricts the "+" operator to numerical values only! Of course, experts may argue that the "+" operator overloading is a huge design flaw of the Java language. But even so, JSF EL is not the right place to fix it! In some cases, a concatenation operator isn't needed, for example:
<ui:repeat var="tab" value="#{tabs}"> <img ... But in case the concatenated...
Created by freyo on May 13, 2011 15:45:29
Last update: September 20, 2011 08:08:12
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/
