Integer 传递

public class TestInteger { public static void main(String[] args) { Integer ix = new Integer(5); TestInteger ti = new TestInteger(); System.out.println(System.identityHashCode(ix)); ti.test(ix); System.out.println(System.identityHashCode(ix)); } public void test(Integer i){ System.out.println(System.identityHashCode(i)); i = new Integer(5); System.out.println(System.identityHashCode(i)); i++; System.out.println(System.identityHashCode(i)); } }

/**
 * The value of the {[@code](https://my.oschina.net/codeo) Integer}.
 *
 * @serial
 */
private final int value;

用final 修饰。

转载于:https://my.oschina.net/u/2427170/blog/1788804