classloader

I know this has probably something to do with class loaders, however I couldn't find an example (it might be I'm google-ing for the wrong keywords. I am trying to load a class (or a method) form a string. The string doesn't contain the name of a class, but the code for a class, e.g. class MyClass implements IMath { public int add(int x, int y) { return x + y; } } and then do something like this: String s = "class MyClass implements IMath { public int add(int x, int y) { return x + y; }}"; IMath loadedClass = someThing.loadAndInitialize(string); int result = loadedClass.add(5,6); Now obviously,

I studied java classloader rencently. Now I want to write a class that has the same package name and class name as one of class in rt.jar. For example, write a java.lang.String class by myself, and how to break the parents delegation model to make the jvm load my java.lang.String instead of the one in rt.jar. Re-edit Thx, tried. And ↓↓↓ D:\>java -verbose -Xbootclasspath/p:D:/myrt.jar -jar exe.jar [Opened D:\myrt.jar] [Opened C:\java\jre\lib\rt.jar] [Loaded java.lang.Object from C:\java\jre\lib\rt.jar] [Loaded java.lang.String from D:\myrt.jar] [Loaded java.io.Serializable from C:\java\jre\lib

I'm having a hard time figuring out where the problem is coming from, so I'm posting this in the hopes that others might have found something similar to this elsewhere and are kind enough to share their insight. I'm using a JBoss 5.0.1.GA application server running on top of a Sun Java 1.6.0-13 JDK . For the WAR file in the generated Web Service, I use a Axis2 1.4 WS engine whose JAR files are inserted by Eclipse Galileo into the project's WEB-INF/lib directory when creating the Webservice from the given "worker" class in the Dynamic Web Project. The relevant code snippet follows: String sUrl

I have a java class which creates a custom classloader based on javassist class loader on start up and then run the real program class. I'm getting the following error: log4j:ERROR A "org.apache.log4j.ConsoleAppender" object is not assignable to a "org.apache.log4j.Appender" variable. log4j:ERROR The class "org.apache.log4j.Appender" was loaded by log4j:ERROR [javassist.Loader@6f97b10a] whereas object of type log4j:ERROR "org.apache.log4j.ConsoleAppender" was loaded by [java.net.URLClassLoader@5b414a8d]. log4j:ERROR Could not instantiate appender named "stdout". The problem is related to the

Ok so this is a newbie question on java, but i can't seem to get my head around it. I have the following code inside my class private static final String [] LIST_CODE = gerarListCode(); private static final int [][] LIST_INTEGER = new int [][] { {947,947}, {110,103}, {947,958}, {110,120}, {947,954}, {103,107}, {947,967}, {110,99,104}}; private static String [] gerarListCode() { String [] listCode = new String [LIST_INTEGER.length]; for (int i=0 ; i<LIST_INTEGER.length ; i++) { //do some stuff } return listaUnicode; } This code is giving me a initialization exception due to a

I would like to replace the content of some methods at runtime. I know I can use javassist for this but it does not work because the classes I would like to enhance are already loaded by the system classLoader . How can I do, to replace the content of a method at runtime ? Should I try to unload the class ? How can I do that ? I saw it was possible but I could not figure out how to do it. If possible, I would like to avoid using an external lib for this, I would like to code it my-self. More information: - The class I would like to enhance is contained in a framework (in a jar file) - My code

I want to use the latest hibernate version inside the ear without upgrading the jars on the server. I am following the instructions given here - http://jaitechwriteups.blogspot.com/2008/08/how-to-upgrade-hibernate-in-jboss.html . However the problem now is the application is not taking the jboss-local-jdbc.rar sitting in the deploy folder. 2009-07-21 09:01:50,347 INFO [org.jboss.system.ServiceConfigurator] Problem configuring service jboss.jca:service=DataSourceBinding,name=MockDS org.jboss.deployment.DeploymentException: Exception setting attribute ConnectionManager = jboss.jca:service

When we invoke java command with -cp command then we provide some directories and jar files. Does jvm load all the classes mentioned by the classpath Or it is just a super set of all classes which jvm will look up to load when required? Does jvm load all the classes mentioned by the classpath Or it is just a super set of all classes which jvm will look up to load when required? JVM loads classes form the classpath on the need basis i.e. when a reference is found for the class, it is loaded. Also there is a hierarchy of class loaders in JVM, a class loaded by the parent class loader is used by