gistfile1.java

package com.garytrakhman.common;

public class FinalTest {
	private String test;

	{
		// works
		new Runnable() {
			@Override
			public void run() {
				System.out.print(test);
			}
		}.run();
	}

	// Works
	void test2() {
		new Runnable() {
			@Override
			public void run() {
				System.out.print(test);
				// works, test lives within heap in the
				// object, so it's not copied, but
				// rather referenced
			}
		}.run();
	}

	void test3() {
		final String test2 = null;

		// 1
		new Runnable() {

			@Override
			public void run() {
				System.out.print(test2);
				// test2 must be final, since it lives on test3()'s stack (the
				// ref not the value)... and
				// must be allocated to the heap
			}
		}.run();

		String test3 = null;
		// 2
		class TestClass implements Runnable {
			private final String test;

			public TestClass(String test) {
				this.test = test;
			}

			@Override
			public void run() {
				System.out.print(test);
			}
		}
		Runnable a = new TestClass(test3);
		// 1 and 2 are equivalent... the reference test3 lives on the function
		// stack, a new reference is created in heap due to the TestClass
		// constructor

		test3 = "go";

		a.run(); // the string within a will be null still

		// so basically, it's final since it has a double-meaning, changing it
		// wouldn't change its meaning within the anonymous inner class object,
		// since it's defined on the stack, but must also live on the object's
		// heap, get it?
	}

}