Archive for category Java
Encrypt with PHP – Decrypt with Java
For security reason, I wanted to encrypt the data transferred between PHP web services and a Java application. But the problem was to encrypt the data with PHP in a way that it is possible to decrypt it using Java.
It obviously exists a lot of ways of doing this. But here is the way I choose:
- Use a secret key and an initialisation vector for the encryption and decryption
- Use the mcrypt PHP module for the encryption
- Use the javax.crypto Java package for the decryption
Please find below the PHP code for the encryption:
function encrypt($message, $initialVector, $secretKey) {
return base64_encode(
mcrypt_encrypt(
MCRYPT_RIJNDAEL_128,
md5($secretKey),
$message,
MCRYPT_MODE_CFB,
$initialVector
)
);
}
And please see below the Java code for the decryption:
public static String md5(String input) throws NoSuchAlgorithmException {
MessageDigest md = MessageDigest.getInstance("MD5");
byte[] messageDigest = md.digest(input.getBytes());
BigInteger number = new BigInteger(1, messageDigest);
return number.toString(16);
}
public String decrypt(String encryptedData, String initialVectorString, String secretKey) {
String decryptedData = null;
try {
SecretKeySpec skeySpec = new SecretKeySpec(md5(secretKey).getBytes(), "AES");
IvParameterSpec initialVector = new IvParameterSpec(initialVectorString.getBytes());
Cipher cipher = Cipher.getInstance("AES/CFB8/NoPadding");
cipher.init(Cipher.DECRYPT_MODE, skeySpec, initialVector);
byte[] encryptedByteArray = (new org.apache.commons.codec.binary.Base64()).decode(encryptedData.getBytes());
byte[] decryptedByteArray = cipher.doFinal(encryptedByteArray);
decryptedData = new String(decryptedByteArray, "UTF8");
} catch (Exception e) {
LOGGER.debug("Problem decrypting the data", e);
}
return decryptedData;
}
EDIT: The line number.toString(16) of the md5 method needs to be replaced by String.format("%032x", number). See this article for more details.
Upgrade to RichFaces 3.3.3.Final
From time to time, it is good to upgrade the application libraries to the latest stable version. Especially the frontend libraries as the browsers are constantly involving and new ones are coming on the market.
This is why I wanted to upgrade the RichFaces library on one of my web application which was still using the version 3.3.0.GA with JSF/MyFaces 1.2.5.
The RichFaces dependency was looking like the following in my pom.xml file:
<dependency>
<groupId>org.richfaces.ui</groupId>
<artifactId>richfaces-ui</artifactId>
<version>3.3.0.GA</version>
<scope>compile</scope>
</dependency>
The upgrade should be straightforward.
But when changing to the version 3.3.3.Final, I got the following error:
2010-10-13 15:56:14.959::WARN: Error starting handlers java.lang.NoClassDefFoundError: org/ajax4jsf/component/SequenceDataAdaptor at java.lang.ClassLoader.defineClass1(Native Method) at java.lang.ClassLoader.defineClassCond(ClassLoader.java:632) at java.lang.ClassLoader.defineClass(ClassLoader.java:616) at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:141) at java.net.URLClassLoader.defineClass(URLClassLoader.java:283) at java.net.URLClassLoader.access$000(URLClassLoader.java:58) at java.net.URLClassLoader$1.run(URLClassLoader.java:197) at java.security.AccessController.doPrivileged(Native Method) at java.net.URLClassLoader.findClass(URLClassLoader.java:190) at org.mortbay.jetty.webapp.WebAppClassLoader.loadClass(WebAppClassLoader.java:366) at org.mortbay.jetty.webapp.WebAppClassLoader.loadClass(WebAppClassLoader.java:337) at java.lang.ClassLoader.defineClass1(Native Method) at java.lang.ClassLoader.defineClassCond(ClassLoader.java:632) at java.lang.ClassLoader.defineClass(ClassLoader.java:616) at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:141) at java.net.URLClassLoader.defineClass(URLClassLoader.java:283) at java.net.URLClassLoader.access$000(URLClassLoader.java:58) at java.net.URLClassLoader$1.run(URLClassLoader.java:197) at java.security.AccessController.doPrivileged(Native Method) at java.net.URLClassLoader.findClass(URLClassLoader.java:190) at org.mortbay.jetty.webapp.WebAppClassLoader.loadClass(WebAppClassLoader.java:366) at org.mortbay.jetty.webapp.WebAppClassLoader.loadClass(WebAppClassLoader.java:337) at java.lang.ClassLoader.defineClass1(Native Method) at java.lang.ClassLoader.defineClassCond(ClassLoader.java:632) at java.lang.ClassLoader.defineClass(ClassLoader.java:616) at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:141) at java.net.URLClassLoader.defineClass(URLClassLoader.java:283) at java.net.URLClassLoader.access$000(URLClassLoader.java:58) at java.net.URLClassLoader$1.run(URLClassLoader.java:197) at java.security.AccessController.doPrivileged(Native Method) at java.net.URLClassLoader.findClass(URLClassLoader.java:190) at org.mortbay.jetty.webapp.WebAppClassLoader.loadClass(WebAppClassLoader.java:366) at org.mortbay.jetty.webapp.WebAppClassLoader.loadClass(WebAppClassLoader.java:337) at java.lang.Class.forName0(Native Method) at java.lang.Class.forName(Class.java:247) at org.apache.myfaces.shared_impl.util.ClassUtils.classForName(ClassUtils.java:132) at org.apache.myfaces.shared_impl.util.ClassUtils.simpleClassForName(ClassUtils.java:158) at org.apache.myfaces.application.ApplicationImpl.addComponent(ApplicationImpl.java:564) at org.apache.myfaces.config.FacesConfigurator.configureApplication(FacesConfigurator.java:650) at org.apache.myfaces.config.FacesConfigurator.configure(FacesConfigurator.java:277) at org.apache.myfaces.webapp.AbstractFacesInitializer.buildConfiguration(AbstractFacesInitializer.java:131) at org.apache.myfaces.webapp.Jsp21FacesInitializer.initContainerIntegration(Jsp21FacesInitializer.java:64) at org.apache.myfaces.webapp.AbstractFacesInitializer.initFaces(AbstractFacesInitializer.java:83) at org.apache.myfaces.webapp.StartupServletContextListener.contextInitialized(StartupServletContextListener.java:72) at org.mortbay.jetty.handler.ContextHandler.startContext(ContextHandler.java:540) at org.mortbay.jetty.servlet.Context.startContext(Context.java:135) at org.mortbay.jetty.webapp.WebAppContext.startContext(WebAppContext.java:1220) at org.mortbay.jetty.handler.ContextHandler.doStart(ContextHandler.java:510) at org.mortbay.jetty.webapp.WebAppContext.doStart(WebAppContext.java:448) at org.mortbay.jetty.plugin.Jetty6PluginWebAppContext.doStart(Jetty6PluginWebAppContext.java:110) at org.mortbay.component.AbstractLifeCycle.start(AbstractLifeCycle.java:40) at org.mortbay.jetty.handler.HandlerCollection.doStart(HandlerCollection.java:152) at org.mortbay.jetty.handler.ContextHandlerCollection.doStart(ContextHandlerCollection.java:156) at org.mortbay.component.AbstractLifeCycle.start(AbstractLifeCycle.java:40) at org.mortbay.jetty.handler.HandlerCollection.doStart(HandlerCollection.java:152) at org.mortbay.component.AbstractLifeCycle.start(AbstractLifeCycle.java:40) at org.mortbay.jetty.handler.HandlerWrapper.doStart(HandlerWrapper.java:117) at org.mortbay.jetty.Server.doStart(Server.java:222) at org.mortbay.component.AbstractLifeCycle.start(AbstractLifeCycle.java:40) at org.mortbay.jetty.plugin.Jetty6PluginServer.start(Jetty6PluginServer.java:132) at org.mortbay.jetty.plugin.AbstractJettyMojo.startJetty(AbstractJettyMojo.java:357) at org.mortbay.jetty.plugin.AbstractJettyMojo.execute(AbstractJettyMojo.java:293) at org.mortbay.jetty.plugin.AbstractJettyRunMojo.execute(AbstractJettyRunMojo.java:203) at org.mortbay.jetty.plugin.Jetty6RunMojo.execute(Jetty6RunMojo.java:182) at org.apache.maven.plugin.DefaultPluginManager.executeMojo(DefaultPluginManager.java:451) at org.apache.maven.lifecycle.DefaultLifecycleExecutor.executeGoals(DefaultLifecycleExecutor.java:558) at org.apache.maven.lifecycle.DefaultLifecycleExecutor.executeStandaloneGoal(DefaultLifecycleExecutor.java:512) at org.apache.maven.lifecycle.DefaultLifecycleExecutor.executeGoal(DefaultLifecycleExecutor.java:482) at org.apache.maven.lifecycle.DefaultLifecycleExecutor.executeGoalAndHandleFailures(DefaultLifecycleExecutor.java:330) at org.apache.maven.lifecycle.DefaultLifecycleExecutor.executeTaskSegments(DefaultLifecycleExecutor.java:291) at org.apache.maven.lifecycle.DefaultLifecycleExecutor.execute(DefaultLifecycleExecutor.java:142) at org.apache.maven.DefaultMaven.doExecute(DefaultMaven.java:336) at org.apache.maven.DefaultMaven.execute(DefaultMaven.java:129) at org.apache.maven.cli.MavenCli.main(MavenCli.java:287) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25) at java.lang.reflect.Method.invoke(Method.java:597) at org.codehaus.classworlds.Launcher.launchEnhanced(Launcher.java:315) at org.codehaus.classworlds.Launcher.launch(Launcher.java:255) at org.codehaus.classworlds.Launcher.mainWithExitCode(Launcher.java:430) at org.codehaus.classworlds.Launcher.main(Launcher.java:375) Caused by: java.lang.ClassNotFoundException: org.ajax4jsf.component.SequenceDataAdaptor at java.net.URLClassLoader$1.run(URLClassLoader.java:202) at java.security.AccessController.doPrivileged(Native Method) at java.net.URLClassLoader.findClass(URLClassLoader.java:190) at java.lang.ClassLoader.loadClass(ClassLoader.java:307) at org.codehaus.classworlds.RealmClassLoader.loadClassDirect(RealmClassLoader.java:195) at org.codehaus.classworlds.DefaultClassRealm.loadClass(DefaultClassRealm.java:255) at org.codehaus.classworlds.DefaultClassRealm.loadClass(DefaultClassRealm.java:274) at org.codehaus.classworlds.RealmClassLoader.loadClass(RealmClassLoader.java:214) at java.lang.ClassLoader.loadClass(ClassLoader.java:248) at org.mortbay.jetty.webapp.WebAppClassLoader.loadClass(WebAppClassLoader.java:375) at org.mortbay.jetty.webapp.WebAppClassLoader.loadClass(WebAppClassLoader.java:337) ... 82 more
What happened here? I simply changed the version number and it now does NOT work! 🙁
Looking at the exception, it seems that it cannot find the class org.ajax4jsf.component.SequenceDataAdaptor which is part of the richfaces-impl library. Why not?
Well, in fact, it is quite simple! It appears that from the version 3.3.3 of RichFaces, you now have to specifically add the richfaces-impl dependency to your pom.xml file such as:
<dependency>
<groupId>org.richfaces.ui</groupId>
<artifactId>richfaces-ui</artifactId>
<version>3.3.3.Final</version>
<scope>compile</scope>
</dependency>
<dependency>
<groupId>org.richfaces.framework</groupId>
<artifactId>richfaces-impl</artifactId>
<version>3.3.3.Final</version>
<scope>compile</scope>
</dependency>
Why do we have to manually add this dependency? This is because the new version of RichFaces allows you to use JSF 2.0 instead of JSF 1.2. To do that, simply add the library richfaces-impl-jsf2 instead of richfaces-impl in your pom.xml file.
Please click on the following link for the JBoss manual about this configuration:
http://community.jboss.org/wiki/HowtoaddRichFaces33xtomavenbasedproject
The selfRendered attribute
This is an interesting problem related to the RichFaces rich:suggestionbox tag.
Let’s take the following code:
<rich:suggestionbox for="q" minChars="1"
suggestionAction="#{myBean.mySuggestionAction}" var="result"
limitToList="true">
<h:column>
<h:outputText value="#{result}" />
</h:column>
</rich:suggestionbox>
If you use the code above as it is, the whole page is going to be processed each time the suggestionAction is called. And because the minChars attribute is set to 1, the action is going to be called each time the user enters a character! 😮
For obvious reason, such as performance issue, this is not ideal.
To avoid this behaviour, you simply need to set the attribute selfRendered to true as shown below:
<rich:suggestionbox for="q" minChars="1"
suggestionAction="#{myBean.mySuggestionAction}" var="result"
limitToList="true" selfRendered="true">
<h:column>
<h:outputText value="#{result}" />
</h:column>
</rich:suggestionbox>
Here is the description of the selfRendered attribute from RichFaces documentation:
If “true”, forces active Ajax region render response directly from stored components tree, bypasses page processing. Can be used for increase performance. Also, must be set to ‘true’ inside iteration components, such as dataTable.
Don’t hesitate to add this attribute to increase the performance of your website. 😉
loadBundle’s behaviour with JSTL tags
Let’s start with a bit of knowledge.
f:loadBundle is a JSF tag which loads a resource bundle and saves it as a variable in the request scope. The RichFaces a4j:loadBundle tag is a substitution for the f:loadBundle tag and allows to use reference to bundle messages during the Ajax re-rendering.
When I discovered the RichFaces tag, I immediately replaced all the f:loadBundle tags by a4j:loadBundle. Was I right? I thought at first, but then I got a problem. 🙁
The problem was appearing when I started mixing RichFaces and JSF tags.
For example, let’s take the following resource bundle:
active=true
And the following code:
<a4j:loadBundle basename="Messages" var="msg" />
Active is #{msg.active} --
<c:if test="#{msg.active}">
Hello World!
</c:if>
This displays ‘Active is true --‘.
What is wrong there? The active message is true but the c:if condition failed! 😯
Let’s now try the following:
<a4j:loadBundle basename="Messages" var="msg" />
Active is #{msg.active} --
<c:if test="#{empty msg.active}">
Hello World!
</c:if>
This displays ‘Active is true -- Hello World!‘.
What does that mean? It seems that JSTL doesn’t get the value of the active message but gets an empty string instead!
In conclusion, if the resource bundle is loading using the RichFaces tag, the messages will be not visible by the JSTL tags.
To fix this problem, you will have to also load the resource bundle using the JSF tag:
<a4j:loadBundle basename="Messages" var="msg" />
<f:loadBundle basename="Messages" var="msg" />
Active is #{msg.active} --
<c:if test="#{msg.active}">
Hello World!
</c:if>
As expected, this displays ‘Active is true -- Hello World!‘. 🙂
Clock change affecting date display
This is a very particular problem which happens only during the summer and not even in all the countries ! 😮
The problem is related to the Daylight Saving Time (DST), also called British Summer Time (BST):
Daylight saving time is the practice of temporarily advancing clocks so that afternoons have more daylight and mornings have less. Typically clocks are adjusted forward one hour near the start of spring and are adjusted backward in autumn.
Okay, so how do we display dates with JSF?
Let’s take this can’t-be-simpler bean:
public class MyBean {
public Date getDate() {
return new Date();
}
}
And let’s insert the following code in a JSF page:
#{myBean.date}
The result is Fri Sep 17 20:03:14 BST 2010 (when I wrote this article).
If I check my clock, the date and time above are correct.
So far so good. 🙂
Let’s now use the h:outputText tag from JSF:
<h:outputText value="#{myBean.date}"/>
The result is Sep 17, 2010.
Alright, the date is correct but the time is not displayed…
Let’s use the f:convertDateTime tag to also display the time:
<h:outputText value="#{myBean.date}">
<f:convertDateTime pattern="E MMM dd HH:mm:ss z yyyy" />
</h:outputText>
The result is Fri Sep 17 19:03:14 GMT 2010.
What can we see here? The time went one hour backward!
Why that? well, simply because the date is now displayed in GMT, instead of BST earlier.
So, this means that the h:outputText tag is displaying the date in GMT by default, which would be fine in winter but not in summer.
In order to fix this behaviour, you need to add the attribute timeZone to the f:convertDateTime tag such as:
<h:outputText value="#{myBean.date}">
<f:convertDateTime pattern="E MMM dd HH:mm:ss z yyyy" timeZone="GB" />
</h:outputText>
Note that if you put BST instead of GB in the timeZone attribute, the time zone is going to be actually set to BDST which stands for Bangladesh Daylight Saving Time! 😀
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