java 遍历map时删除元素

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/* * To change this template, choose Tools | Templates * and open the template in the editor. */import java.util.HashMap;import java.util.Set;import java.util.Iterator;import java.util.Map; /** * * @author fuzuotao */public class TestMap {        /* 在遍历Map过程中,不能用map.put(key,value),map.remove(key)来修改和删除元素， 会引发并发修改异常*/        public static void main(String[] args)    {        HashMap<String, String> test_map = new HashMap<String, String>();        test_map.put("1", "test1");        test_map.put("2", "test2");        test_map.put("3", "test3");        test_map.put("4", "test4");                Set mapset = test_map.entrySet();        Iterator iterator = mapset.iterator();        while(iterator.hasNext())        {            Map.Entry mapentry = (Map.Entry)iterator.next();             String key = mapentry.getKey().toString();            String value = mapentry.getValue().toString();                        System.out.printf("key: %s value:%s\r\n", key, value);         }                System.out.printf("***************deleting************\r\n");                Iterator<Map.Entry<String, String>> it = test_map.entrySet().iterator();        while(it.hasNext())        {            Map.Entry<String, String> entry= it.next();            String key= entry.getKey();            int k = Integer.parseInt(key);            if(k%2==1)            {                System.out.printf("delete key:%s value:%s\r\n", key, entry.getValue());                it.remove(); //OK             }        }                System.out.printf("***************result************\r\n");                iterator = mapset.iterator();               while(iterator.hasNext())        {            Map.Entry mapentry = (Map.Entry)iterator.next();            String key = mapentry.getKey().toString();            String value = mapentry.getValue().toString();                        System.out.printf("key: %s value:%s\r\n", key, value);         }            }}
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