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Created by Dr. Xi on August 15, 2012 12:05:39    Last update: August 15, 2012 12:05:39
Use OpenSSL's s_client command to fetch a page manually: $ openssl s_client -connect localhost:443 -state -... Sample session for Google: $ openssl s_client -connect www.google.com:443 -st... Resource: SSL/TLS Strong Encryption: FAQ
Created by Fang on March 15, 2012 10:24:35    Last update: March 15, 2012 10:24:35
Suppose that I have an email field annotated with: @NotEmpty(message="Please enter email address") ... Bean validation will trigger two errors when no email address is entered: the email field is empty an empty email field is not a valid email address Displaying both errors to the user with <form:errors> would be redundant and confusing: <%@ taglib uri="http://www.springframework.org/tag... This is how to display the first error only: <spring:bind path="emailAddress"> <c:if test="$...
Created by Fang on February 27, 2012 12:19:19    Last update: February 27, 2012 12:19:19
Mapping Java objects to Jackson JSON is pretty simple. But if you name a JSON field wrong, you'll get the "Unrecognized field ... (Class ...), not marked as ignorable" error. The rule for mapping a Java bean attribute name to a JSON field name is: lower all leading capital letters until the first lower case letter . For example, this Java class: package com.example; public class Person { ... maps to this JSON string: { "firstName": "Jane", "lastName": "... Test code: package com.example; import java.net.URL; ...
Created by Dr. Xi on July 11, 2011 12:24:10    Last update: July 11, 2011 12:25:44
This code snippet import java.util.*; public class UncheckedCast ... fails with a compilation error and a warning: $ javac -Xlint:unchecked UncheckedCast.java Unc... Because List<String> is not a reifiable type, the Java Runtime does not have enough information to verify the type or do the type casting. This is fixed by changing List<String> to List<?> (or to the raw type List ): public static void main(String[] args) { Ob...
Created by freyo on May 17, 2011 11:13:17    Last update: May 17, 2011 11:13:17
This is an odd-ball content provider in that it doesn't provide database records, but provides a resource as a stream. It can be used to provide media files or XML resources. Start the project with: tools/android create project --package com.android... Create assets directory and add an XML file ( assets/demo.xml ): <? xml version="1.0" encoding="UTF-8"?> <people... Edit the layout ( res/layout/main.xml ): <?xml version="1.0" encoding="utf-8"?> <LinearL... Edit src/com/android/cptest/Dummy.java : package com.android.cptest; import java.io.... Add content provider ( src/com/android/cptest/XmlResource.java ): package com.android.cptest; import java.io.... Update AndroidManifest.xml : <?xml version="1.0" encoding="utf-8"?> <manifes... Add this section to the end of build.xml : <target name="-package-resources"> <ech... Build and install: ant install Screenshot: Remove the Dummy activity ( AndroidManifest.xml ): <?xml version="1.0" encoding="utf-8"?> <manifes... Create a new project for...
Created by jinx on April 28, 2011 20:52:45    Last update: April 29, 2011 13:27:31
This is normally a syntax error just before some variable. Try some of these: Missing operator before a variable: <?php $a = 'ab'; echo('Missing conca... Missing semicolon at end of line: <?php echo('Missing semicolon at end of lin... Missing ( and ) in for loop: <?php foreach $a as $i { echo "$i\n"; ... Missing keyword before class variable: <?php class A { // should be var $a; ...
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
Created by Dr. Xi on March 02, 2010 00:07:48    Last update: March 02, 2010 00:07:48
OC4J didn't offer much help in the console. This is all it displayed: 2010-03-01 15:48:21.372 ERROR J2EE EJB-03027 [Fab... However, in the em console, Logs -> Diagnostic Logs gives more details: Message Text [FabulousApp] An error occured deploying EJB mod... Supplemental Text com.evermind.server.ejb.exception.DeploymentExcept... The error was caused by a relationship annotation between two entities, the referenced attribute was removed from the owner side: @OneToMany(cascade=CascadeType.ALL, mapped...
Created by Dr. Xi on February 10, 2010 23:39:37    Last update: February 10, 2010 23:39:37
Example web.xml that includes most frequently used elements. This sample is for Servlet Specification 2.4. <?xml version="1.0" encoding="UTF-8"?> <web-ap...
Created by Dr. Xi on February 09, 2009 23:14:15    Last update: February 09, 2009 23:14:15
This example demonstrates the general steps in creating a custom Java class loader. Normally a class loader would consult its parent class loader when asked to load a class. If it's not loaded by the parent class loader, then the class loader would try to load the class on its own. This class loader tries to load the requested class on its own first, and delegates to the parent only when a java.lang.SecurityException is thrown (which happens when it tries to load core Java classes such as java.lang.String ). The classes are loaded from CLASSPATH through the getResourceAsStream call. It's important to note that when a class is loaded with a certain class loader, all classes referenced from that class are also loaded through the...