Java dynamic function calling

I have a String array that contains names of method in the yyyyyy class

In the xxxxxx class I'm making a yyyyyy instance (say obj). Now I can call obj.function_name(), except I want to read function_name from the String array in a loop. Is this possible?

You can, using reflection. It is done by calling Yyyy.class.getMethod("methodName").invoke(someArgs)

You'd have to handle a bunch of exceptions, and your method must be public. Note that java coding conventions prefer methodName to method_name.

Using reflection, however, should be a last resort. You should be using more object-oriented techniques.

If you constantly need similar features, perhaps you can look at some dynamic language running on the java platform, like Groovy

It's possible using reflection, although you should probably question your design somewhat if you need that sort of behavior. Class.getMethod takes a String for the method name and returns a Method object, which you can then call .invoke on to call the method

These Javadoc pages should be helpful:

• Class.getMethod
• Method.invoke

Sample code (assuming the yyyyyy methods take one int argument, just to show argument passing):

yyyyyy obj = new yyyyyy();
String[] methodNames = {"foo", "bar", "baz"};
for(String methodName : methodNames) {
    Method method = Class.forName("yyyyyy").getMethod(methodName, new Class[] {int.class});
    method.invoke(obj, 4); // 4 is the argument to pass to the method
}