I am trying to get a hold on javassist for one of our companies projects. I wrote this simple class for testing
public class Main {
public void test(){
ClassPool cp = ClassPool.getDefault();
CtClass entity = cp.makeClass("Entity");
try {
entity.addField(CtField.make(" public Integer id;",entity));
entity.addField(CtField.make(" public String name;", entity));
entity.addMethod(CtNewMethod.make("public void say() { System.out.println(12222);}",entity));
Class EntityClass = entity.toClass();
entity.writeFile("/tmp");
Object e= EntityClass.newInstance();
Field name = EntityClass.getField("name");
name.set("Ooldooz", e);
System.out.println(name.get(e));
} catch (CannotCompileException e) {
e.printStackTrace(); //To change body of catch statement use File | Settings | File Templates.
} catch (InstantiationException e) {
e.printStackTrace(); //To change body of catch statement use File | Settings | File Templates.
} catch (IllegalAccessException e) {
e.printStackTrace(); //To change body of catch statement use File | Settings | File Templates.
} catch (NoSuchFieldException e) {
e.printStackTrace(); //To change body of catch statement use File | Settings | File Templates.
} catch (IOException e) {
e.printStackTrace(); //To change body of catch statement use File | Settings | File Templates.
}
}
public static void main(String[] args){
Main main = new Main();
main.test();
}
}
Trying to run, I get this error:
Exception in thread "main" java.lang.IllegalArgumentException: Can not set java.lang.String field Entity.name to java.lang.String
at sun.reflect.UnsafeFieldAccessorImpl.throwSetIllegalArgumentException(UnsafeFieldAccessorImpl.java:146)
at sun.reflect.UnsafeFieldAccessorImpl.throwSetIllegalArgumentException(UnsafeFieldAccessorImpl.java:150)
at sun.reflect.UnsafeFieldAccessorImpl.ensureObj(UnsafeFieldAccessorImpl.java:37)
at sun.reflect.UnsafeObjectFieldAccessorImpl.set(UnsafeObjectFieldAccessorImpl.java:57)
at java.lang.reflect.Field.set(Field.java:657)
at Main.test(Main.java:26)
Can anybody help me out please?