@Test
public void loopTryCatchTest() throws Exception {

    Map<String, Object> a = new HashMap();
    a.put("a", "1");
    a.put("b", null);
    a.put("c", "3");


    for (Map.Entry<String, Object> moEntry : a.entrySet()) {
        try{
        boolean flag = moEntry.getValue().equals("1");
        System.out.println(moEntry.getKey() + "," + moEntry.getValue() + "," + flag);

        } catch(Exception e){
        System.out.println("异常跳出" + e);
      //continue;--- 不需要写continue,因为写不写,都会继续循环,不会异常后直接退出的。
        }
    }

}


执行结果:

a,1,true
异常跳出java.lang.NullPointerException
c,3,false

 

如果try包在for循环外面,则无法达到预期效果,遇到异常抛出,被catch住后,循环无法继续执行。

@Test
public void loopTryCatchTest() throws Exception {

    Map<String, Object> a = new HashMap();
    a.put("a", "1");
    a.put("b", null);
    a.put("c", "3");

    try {
        for (Map.Entry<String, Object> moEntry : a.entrySet()) {

           boolean flag = moEntry.getValue().equals("1");
           System.out.println(moEntry.getKey() + "," + moEntry.getValue() + "," + flag);


        }
    }catch (Exception e) {
      System.out.println("异常跳出" + e);
  }

}
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