Java generics code compiles with javac, fails with Eclipse Helios

Question

I have the following test class that uses generics to overload a method. It works when compiled with javac and fails to compile in Eclipse Helios. My java version is 1.6.0_2

Answer 1

This code is correct, as described in JLS 15.12.2.5 Choosing the Most Specific Method.

Also, consider coding to the interface:

List ss = new ArrayList();
List is = new ArrayList();
// etc.

As @McDowell notes, the modified method signatures appear in the class file:

$ javap build/classes/Test
Compiled from "Test.java"
public class Test extends java.lang.Object{
    public Test();
    public static void main(java.lang.String[]);
    public java.lang.String getFirst(java.util.ArrayList);
    public java.lang.Integer getFirst(java.util.ArrayList);
}

Note that this does not contradict @meriton's observation about the class file. For example, the output of this fragment

Method[] methods = Test.class.getDeclaredMethods();
for (Method m : methods) {
    System.out.println(Arrays.toString(m.getGenericParameterTypes()));
}

shows the formal parameter of main(), as well as the two generic type parameters:

[class [Ljava.lang.String;]
[java.util.ArrayList]
[java.util.ArrayList]