package cn.qlq.fina;
/*** final 关键字使用* @author Administrator**/
public class TestCla {private static final int a = 1;private static final User u = new User();;public static void main(String[] args) {// a = 2;// final修饰的变量不可改变(引用不可变)// u=new User();//引用不可变，不可再指向其他对象，但是引用内容可以改变
        u.setUsername("sssssss");u.setUsername("XXXXXXX");}public void test1(final int x ){
//        x=1;//final修饰的变量不可改变,方法上的形参也不可以变
    }
}

package cn.qlq.test;/*** * @author Administrator**/
public class MyTest {public static final int i = 6;@SuppressWarnings("finally")public static long test1() {String val = "5d";long value = 5;try {value = Long.parseLong(val);} catch (NumberFormatException e) {System.out.println("catch...");return value++;} finally {System.out.println("finally...");value--;return value;}}public static void main(String[] args) {System.out.println(MyTest.test1());}
}

catch...
finally...
5

package cn.qlq.test;/*** * 测试finalize()方法，对象消亡的时候调用的方法，类似于C++的析构函数* @author Administrator**/
public class MyTest {public static final int i = 6; @Overrideprotected void finalize() throws Throwable {System.out.println("对象要死亡");}@SuppressWarnings("finally")public long test1() {String val = "5d";long value = 5;try {value = Long.parseLong(val);} catch (NumberFormatException e) {System.out.println("catch...");return value++;}finally {System.out.println("finally...");value--;return value;}}public static void main(String[] args) {MyTest my = new MyTest();System.out.println(my.test1());my = null;//清空对象的引用，使其被垃圾回收System.gc();//调用GC回收垃圾
    }
}