package test;

import com.example.Interface;

public class Test implements Interface
{
	public void test()
	{
		
	}
}

import com.example.Interface;

cu.accept(new ASTVisitor()
{
	public boolean visit(MethodDeclaration decl)
	{
		for(ITypeBinding binding : decl.resolveBinding().getDeclaringClass().getInterfaces())
		{
			System.out.println(binding.getQualifiedName());
		}
		return true;
	}
});

test.Interface

com.example.Interface