java 遍历map时删除元素

2023年9月26日 248次阅读来源: 摩西科里

import java.util.HashMap;

import java.util.Iterator;

import java.util.Map;

import java.util.Set;

import java.util.Map.Entry;

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> testMap = new HashMap<String,String>();

testMap.put(“1″,”test1”);

testMap.put(“2″,”test2”);

testMap.put(“3″,”test3”);

testMap.put(“4″,”test4”);

Set mapSet = testMap.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 = testMap.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();

}

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);

}

出自http://www.dedecms.com/knowledge/program/jsp-java/2012/0810/4490.html

    原文作者：摩西科里
    原文地址: https://blog.csdn.net/qingzhongren/article/details/7976540
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