package com.wangzhu;import java.util.HashMap;import java.util.Map;/** * 在try、catch、finally块中，若try中有return语句，则返回try中变量的值，<br/> * 不管try块外是否对该变量进行了修改， 都不影响try中return的返回值。<br/> * 若finally中有return语句，则忽略try、catch块中的return语句。<br/> * 若finally中抛出异常，则整个try-catch-finally块中抛出异常。<br/> *  * 注意：<br/> * 尽量在try或者catch中使用return语句，通过finally快中达到对try或者catch返回值的修改是不可行的。<br/> * finally块中避免使用return语句，因为finally快中如果使用return语句，<br/> * 会显示的消化掉try、catch块中的异常信息， 屏蔽了错误的发生。<br/> * finally块中皮面再次抛出异常，否则整个try-catch-finally块的方法抛出异常，并会消化掉try、catch块中的异常。<br/> *  * @author wangzhu2014-7-20下午8:48:43 *  */public class CatchDemo1 {    /**     * 返回：try     *      * @return     */    public static String test() {        String str = "";        try {            str = "try";            return str;        } catch (Exception e) {            str = "catch";            return str;        } finally {            str = "finally";        }    }    /**     * 返回：finally     *      * @return     */    public static String test1() {        String str = "";        try {            str = "try";            return str;        } catch (Exception e) {            str = "catch";            return str;        } finally {            str = "finally";            return str;        }    }    /**     * 返回：catch     *      * @return     */    public static String test2() {        String str = "";        try {            str = "try";            Integer.parseInt(null);            return str;        } catch (Exception e) {            str = "catch";            return str;        } finally {            str = "finally";        }    }    /**     * 返回：finally     *      * @return     */    public static String test3() {        String str = "";        try {            str = "try";            Integer.parseInt(null);        } catch (Exception e) {            str = "catch";            return str;        } finally {            str = "finally";            return str;        }    }    /**     * 返回:finally     *      * @return     */    public static String test4() {        String str = "";        try {            str = "try";            Integer.parseInt(null);            return str;        } catch (Exception e) {            str = "catch";            Integer.parseInt(null);            return str;        } finally {            str = "finally";            // 若去掉return语句则最后会报异常            return str;        }    }    /**     * 返回：finally     *      * @return     */    public static String test5() {        String str = "";        try {            str = "try";            Integer.parseInt(null);            return str;        } catch (NullPointerException e) {            str = "catch";            return str;        } finally {            str = "finally";            // 若去掉return语句则最后会报异常            return str;        }    }    public static String test6(Map<String, Object> map) {        String str = "";        try {            str = "try";            map.put(str, str);            Integer.parseInt(null);            return str;        } catch (NullPointerException e) {            str = "catch";            map.put(str, str);            return str;        } finally {            str = "finally";            map.put(str, str);            // 若去掉return语句则最后会报异常            return str;        }    }    public static void main(String[] args) {        System.out.println("try: " + CatchDemo1.test());        System.out.println("finally: " + CatchDemo1.test1());        System.out.println("catch: " + CatchDemo1.test2());        System.out.println("finally: " + CatchDemo1.test3());        System.out.println("finally: " + CatchDemo1.test4());        System.out.println("finally: " + CatchDemo1.test5());        Map<String, Object> map = new HashMap<String, Object>();        System.out.println("finally: " + CatchDemo1.test6(map));        for (String key : map.keySet()) {            System.out.println(key + "===" + map.get(key));        }    }}