zoukankan      html  css  js  c++  java
  • 取出List<Map<String,Object>>里面Map的key:value值

    1.取出Map其中一个属性的值

    Map map = new HashMap();
    map.put("key1", "value1");
    map.put("key2", "value2");
    List> list = new ArrayList>();
    list.add(map);
    for(int i = 0;i < list.size();i++)
    {
        Map<String,Object> map = list.get(i);
        String authorStr = map.get("key1").toString();
        System.out.println("author" + " : " + authorStr);
    }

    2.取出所有的key:value

    //第一种:
    Map map = new HashMap();
    map.put("key1", "value1");
    map.put("key2", "value2");
    <List> list = new ArrayList>();
    list.add(map);
    for (Map m : list)
    {
        for (String k : m.keySet())
        {
            System.out.println(k + " : " + m.get(k));
        }
    }
    
    //第二种:
    Map map = new HashMap();
    map.put("key1", "value1");
    map.put("key2", "value2");
    <List> list = new ArrayList>();
    list.add(map);
    for(Map map:list)
    {
        for(Map.Entry e:map)
        {
            e.getKey() 和 e.getValue() 就是你想要的
        }
    }
    
    //第三种:
    Map map = new HashMap();
    map.put("key1", "value1");
    map.put("key2", "value2");
    <List> list = new ArrayList>();
    list.add(map);
    for (int i=0;i<list.size();i++)
    {
        Map  map1=(Map)list.get(i);
        Iterator iterator = map1.keySet().iterator();
        while (iterator.hasNext())
        {
            String key = (String) iterator.next();
            Object object = map1.get(key);
            System.out.println(object);
        }
    }
  • 相关阅读:
    Oracle 循环语句
    IDEA---SpringBoot同一个项目多端口启动
    Maven引入oracle驱动包
    Linux安装 PostgreSQL
    Oracle备份及备份策略
    Oracle优化的几个简单步骤
    Oracle RMAN备份策略
    常见的几种索引扫描类型
    插槽内容
    分布式系统session同步解决方案
  • 原文地址:https://www.cnblogs.com/quyixuanblog/p/5217310.html
Copyright © 2011-2022 走看看