Description rene 2011-06-25 13:36:03 EDT

Build Identifier: 20110615-0604

In Java, it is possible to fill generic lists with elements of the wrong type:

List list1 = new ArrayList();
list1.add(42);
List<String> list2 = new ArrayList<String>();
list2.addAll(list1); // unchecked addAll

Then, iterating over such list2 via

for (Object o : list2) {...}

yields different behavior if compiled with JDT (no exception) and JDK (ClassCastException), respectively.


Reproducible: Always

Steps to Reproduce:
1. Compile/Run the class JDTvsJDK (s. below) within Eclipse (JDT): System.out is "JDT compiler".
2. Compile the class using JDK's 'javac' and run with 'java': System.out is "JDK compiler.


import java.util.ArrayList;
import java.util.List;

public class JDTvsJDK {
	public static void main(String[] args) {
		
		List list1 = new ArrayList();
		list1.add(42);
		
		List<String> list2 = new ArrayList<String>();
		list2.addAll(list1); // unchecked addAll
		
		try {
			// JDT cast Integer to Object
			// JDK cast Integer to String (exception) and then to Object
			for (Object o : list2); 
			System.out.println("JDT compiler");			
		} catch (ClassCastException e) {
			System.out.println("JDK compiler");
		}
	}
}