Diego Adrada [https://community.jboss.org/people/diego.adrada] created the discussion "Using Javassist on Eclipse" To view the discussion, visit: https://community.jboss.org/message/817875#817875 -------------------------------------------------------------- Greetings, I'm starting with Javassist, I have implemented an example of Hello World with following code: public class HelloWorld {        public static void main(String[] args) {        new HelloWorld().sayHello();    }      public void sayHello(){        System.out.println("Hello!!! This is the original version!!!");    } } import javassist.CannotCompileException; import javassist.CtClass; import javassist.CtMethod; import javassist.NotFoundException;   import java.io.IOException;   import static javassist.ClassPool.getDefault;     public class ByteCodeInjector {      public static final String CLASS_NAME = "HelloWorld";    public static final String METHOD = "sayHello";      public static void main(String[] argos) throws Exception{        modifyByteCode(CLASS_NAME,METHOD);    }      public static void modifyByteCode(String className ,String methodName)            throws NotFoundException, CannotCompileException, IOException {        //Get the Class implementation byte code        CtClass ctClass = getDefault().get(className);          //Get the method from the Class byte code        CtMethod method= ctClass.getDeclaredMethod(methodName);          /**         * Creating the new Method implementation         */        StringBuffer content = new StringBuffer();        content.append("{\n System.out.println(\"Hello!!! This is the Modified version!!!\");\n } ");          /**         * Inserting the content         */        method.setBody(content.toString());        System.out.println("Replacing Method \' sayHello\' s body with new implementation : " + content);         //modify the actual class File        ctClass.writeFile();    } } This example has already worked well compiling classes from console. My question is about what I need to implement this example in Eclipse? It must have some sort of special consideration? Thank you for your help. -------------------------------------------------------------- Reply to this message by going to Community [https://community.jboss.org/message/817875#817875] Start a new discussion in Javassist Development at Community [https://community.jboss.org/choose-container!input.jspa?contentType=1&...]