import java.util.HashMap;

import java.util.Map;

public class FinallyDemo1 {

    public static void main(String[] args) {

        System.out.println("=================================");

        System.out.println("A情况：finally在try的return执行之后，返回之前。");

        System.out.println("main\ti="+test1());

        System.out.println("=================================");

        System.out.println("B情况：finally在try的return执行之后，返回之前。finally的return将覆盖try的return：");

        System.out.println("main\ti="+test2());

        System.out.println("=================================");

        System.out.println("异常时候，try的return不执行。catch和finally的执行情况与try和finally的执行情况一样。如A情况：");

        System.out.println("main\ti="+test3());

        System.out.println("=================================");

        System.out.println("异常时候，try的return不执行。catch和finally的执行情况与try和finally的执行情况一样。如B情况：");

        System.out.println("main\ti="+test4());

        System.out.println("=================================");

        System.out.println("地址传递的参数，在try-finally中将覆盖返回值。");

        System.out.println("main\tmap="+test5());

        System.out.println("=================================");

        System.out.println("地址传递的参数，在try-finally中将覆盖返回值。");

        System.out.println("main\tmap="+test6());

        System.out.println("=================================");

    }

    /**

     * finally代码块是在try代码块中的return语句执行之后，返回之前执行的。

     * @return

     */

    public static int test1(){

        int i=1;

        try {

            return i+=100;

        } catch (Exception e) {

            System.out.println("catch");

        }finally{

            i++;

            System.out.println("finally\ti="+i);

        }

        return i;

    }

    /**

     * finally代码块中的return语句覆盖try代码块中的return语句

     * @return

     */

    @SuppressWarnings("finally")

    public static int test2(){

        int i=1;

        try {

            return i+=100;

        } catch (Exception e) {

            System.out.println("catch");

        }finally{

            i++;

            System.out.println("finally\ti="+i);

            return i;

        }

    }

    /**

     *  try代码块中的return语句在异常的情况下不会被执行；

     *  catch中的return执行情况与未发生异常时try中return的执行情况完全一样。

     * @return

     */

    @SuppressWarnings("finally")

    public static int test3(){

        int i=1;

        try {

            i=i/0;

            return i+=100;

        } catch (Exception e) {

            System.out.println("catch");

            return i+=100;

        }finally{

            i++;

            System.out.println("finally\ti="+i);

        }

    }

    @SuppressWarnings("finally")

    public static int test4(){

        int i=1;

        try {

            i=i/0;

            return i+=100;

        } catch (Exception e) {

            System.out.println("catch");

            return i+=100;

        }finally{

            i++;

            System.out.println("finally\ti="+i);

            return i;

        }

    }

    /**

     * 值传递：返回值不变

     * 地址传递：返回值会变

     * @return

     */

    public static Map test5(){

        Map<String, String> map = new HashMap<String, String>();

        map.put("param1", "初始化值");

        try {

            System.out.println("try");

            map.put("param1", "try值");

            return map;

        } catch (Exception e) {

            System.out.println("catch");

            map.put("param1", "catch值");

        } finally {

            System.out.println("finally");

            map.put("param1", "finally值");

            map = null;

        }

        return map;

    }

    @SuppressWarnings("finally")

    public static Map test6(){

        Map<String, String> map = new HashMap<String, String>();

        map.put("param1", "初始化值");

        try {

            System.out.println("try");

            map.put("param1", "try值");

            return map;

        } catch (Exception e) {

            System.out.println("catch");

            map.put("param1", "catch值");

        } finally {

            System.out.println("finally");

            map.put("param1", "finally值");

            map = null;

            return map;

        }

    }

}