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Created by Fang on March 30, 2012 10:07:25    Last update: March 08, 2013 13:41:57
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 June 06, 2009 18:31:44    Last update: June 25, 2012 12:37:35
You can use the system call from the os module to execute an external program: >>> import os >>> os.system(the_command_line_st... However, the path to the executable contains a space character, the system call treats the strings after the first space as arguments, causing an error. Python doc recommends the use of the subprocess module: The subprocess module provides more powerful facilities for spawning new processes and retrieving their results; using that module is preferable to using this function. For example, using wget to get the google home page: >>> from subprocess import Popen, PIPE >>> (out... or >>> import subprocess >>> subprocess.call(['cur...
Created by Fang on September 07, 2009 20:44:15    Last update: November 03, 2011 14:43:19
Step 1: Repackage a web app as EAR A Java EE application is a multimodule Maven project. At the very least you'll need to package a WAR and an EAR. To get started, I'll simply re-package the simple webapp as an EAR. Create a directory named javaee-app Copy the webapp from here to javaee-app . Rename struts1app to webapp . Create pom.xml under javaee-app : <project> <modelVersion>4.0.0</modelVersion>... Create a directory named ear under javaee-app . Create pom.xml under ear : <project> <modelVersion>4.0.0</modelVersion>... Modify pom.xml in the webapp directory so that it looks like this: <project> <modelVersion>4.0.0</modelVersion> ... Build with " mvn package " in the javaee-app directory. You can see that ear-1.0.ear is successfully generated in javaee-app/ear/target . Maven successfully resolves dependencies between the sub-projects....
Created by freyo on September 07, 2011 16:46:14    Last update: September 07, 2011 19:23:00
The Android unit test framework is based on JUnit 3 , not JUnit 4. Test cases have to extend junit.framework.TestCase or a subclass (such as android.test.InstrumentationTestCase ). Tests are identified by public methods whose name starts with test , not methods annotated with @Test (as in JUnit 4). An Android test suite is packaged as an APK, just like the application being tested. To create a test package, first you need to identify the application package it is testing. Google suggests to put the test package source in a directory named tests/ alongside the src/ directory of the main application. At runtime, Android instrumentation loads both the test package and the application under test into the same process. Therefore, the tests can invoke methods on...
Created by freyo on August 17, 2011 12:29:46    Last update: August 17, 2011 12:29:46
In Android.mk , you can define LOCAL_JARJAR_RULES like this: LOCAL_JARJAR_RULES := $(LOCAL_PATH)/jarjar-rules.t... and in jarjar-rules.txt define a rule like this: rule org.bouncycastle.** com.android.@0 The build will change all org.bouncycastle to com.android.org.bouncycastle . Therefore, in your classes which are dependent on the library produced, the import statements should look like: import com.android.org.bouncycastle... Help for the jarjar utility (in prebuilt/common/jarjar/ ): $ java -jar jarjar-1.0rc8.jar Jar Jar Links - ...
Created by Dr. Xi on April 26, 2011 20:12:01    Last update: April 28, 2011 15:28:12
An XML schema is a definition of XML files, in XML. It plays the same role as old-time DTDs. Overall, an XML schema file looks like this: <schema attributeFormDefault = (qualified | u... The attribute meanings: targetNamespace : The name space targeted by the current schema definition. It can be any URI. id and version : For user convenience, the W3C spec defines no semantics for them. xml:lang : Natural language identifier defined by RFC 3306 . attributeFormDefault and elementFormDefault : Set default values for the form attribute for attribute and element declarations. blockDefault and finalDefault : Set default values for the block and final attributes for attribute and element declarations. The W3C defined some built-in datatypes . Examples of primitive datatypes are: string ,...
Created by freyo on April 12, 2011 13:05:33    Last update: April 12, 2011 13:06:26
android:sharedUserId (from Android doc): The name of a Linux user ID that will be shared with other applications. By default, Android assigns each application its own unique user ID. However, if this attribute is set to the same value for two or more applications, they will all share the same ID — provided that they are also signed by the same certificate. Application with the same user ID can access each other's data and, if desired, run in the same process. Declare sharedUserId in AndroidManifest.xml : <manifest xmlns:android="http://schemas.android.co... Retrieve sharedUserId programmatically: import android.content.pm.PackageManager; impor...
Created by Dr. Xi on March 28, 2011 20:51:30    Last update: March 28, 2011 20:53:46
HTTP basic authentication is just Base64 encoded user name and password passed in as the Authorization header. So the following code works: // encode user name and password String credent... However, since JDK 1.2, there's a more Java friendly way: Authenticator.setDefault(new Authenticator() { ... Test code: import java.net.*; import java.io.*; pub...
Created by nogeek on November 11, 2010 00:26:08    Last update: November 11, 2010 00:29:43
This one is even more weird: it worked on Windows but failed on Linux, using default tools JDK1.6.0_20 on both. The exception thrown was: java.lang.RuntimeException: Invalid conversion fro... And the stack trace: java.lang.RuntimeException: Invalid conversion fro... This was the XSL used: <?xml version="1.0" encoding="ISO-8859-1"?> <xs... The problem was , DateUtil.java had two getDate methods, one taking long parameter, the other taking a String parameter. And Java's XSLT get confused about which one to use: import java.util.Date; import java.text.SimpleD...
Created by Fang on August 10, 2010 21:37:36    Last update: October 25, 2010 20:18:47
The tags <fmt:formatNumber> Format a numeric value as number , currency or percentage - controlled by the type attribute (defaults to number if type is missing). Syntax: <fmt:formatNumber value="numericValue" [type="... Attributes: Name Dynamic? Type Description value true String or Number Numeric value to be formatted. type true String Specifies whether the value is to be formatted as number, currency, or percentage. pattern true String Custom formatting pattern, must follow the pattern syntax specified by the class java.text.DecimalFormat . currencyCode true String ISO 4217 currency code. Applied only when formatting currencies (i.e. if type is equal to "currency"); ignored otherwise. currencySymbol true String Currency symbol. Applied only when formatting currencies (i.e. if type is equal to "currency"); ignored otherwise. It is used only when currencyCode is...
Created by Fang on April 04, 2010 04:12:14    Last update: July 21, 2010 14:52:58
The tags <c:if> The <c:if> tag may be used with or without body content: <!-- Without body content, used to export vari... In my opinion, the version without body content is pretty much useless (the <c:set> tag is a lot more meaningful for this purpose). If body content exists, it is inserted into the page if the testCondition is true . Optional attributes var and scope may be specified. If var is specified, a variable whose name is the value of var is exported to the associated scope ( pageScope if no scope is specified). The type of the exported variable is Boolean and its value is the value of the testCondition . <c:choose>, <c:when>, <c:otherwise> These tags imitate the Java control structure if...else...
Created by Dr. Xi on October 23, 2008 03:54:04    Last update: October 23, 2008 03:57:44
Add validator plugin in struts-config.xml <struts-config> . . . ... Set validate="true" on action form <struts-config> <!-- ========== Form Bean De... Add validation rules in validation.xml <?xml version='1.0' encoding='windows-1252'?> <... If you override validate , make sure super.validate is called. package com.example; import javax.servlet.h... Read the documentation: http://struts.apache.org/1.2.4/userGuide/dev_validator.html