遍历 List-Map-String-Object-

最新推荐文章于 2023-04-17 13:48:04 发布

原创最新推荐文章于 2023-04-17 13:48:04 发布 · 1.6k 阅读

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本文通过具体示例展示了如何在Java中使用HashMap和ArrayList进行数据操作。包括元素的添加、检索以及遍历过程，特别强调了HashMap的键值对存储方式和ArrayList的动态数组特性。此外，还介绍了如何在List中存储Map类型的数据，并实现特定值的查找。

package com.mapping;

import java.util.ArrayList;
import java.util.Date;
import java.util.HashMap;
import java.util.List;
import java.util.Map;


public class MapTest {
	public static void main(String[] args) {
		
		
		/*Map<String, String> map = new HashMap<String, String>();
		String version_Id = "";
		map.put("VERSION_ID", version_Id);	//点击编辑/处理时只有 AREA_ID
		map.put("one","one");
		map.put("two","two");
		map.put("one","three");
		for (Map.Entry<String, String> entry : map.entrySet()) { 
		  System.out.println("Key = " + entry.getKey() + ", Value = " + entry.getValue()); 
		}
		System.out.println(map.size());
		//System.out.println(a.get("d"));
		 * 
*/		
		List<Map<String,Object>> queryQzBySxList = new ArrayList<Map<String,Object>>();
		Map<String,Object> map1 = new HashMap<String,Object>();
		map1.put("a","aa");
		map1.put("b","bb");
		map1.put("c","cc");
		queryQzBySxList.add(map1);
		
		Map<String,Object> map2 = new HashMap<String,Object>();
		map2.put("d","dd");
		map2.put("e","ee");
		map2.put("f","ff");
		queryQzBySxList.add(map2);
		
		String bussinessChildType="dd";
		boolean flag = false;
		for(Map<String,Object> map:queryQzBySxList){
			if(map.containsValue(bussinessChildType)){
				flag = true;
				break;
			}
			/*
			for(Map.Entry<String,Object> map : queryQzBySxList.entrySet()){
           			 System.out.println(map.getKey()+ " : "+map.getValue());
       	 }
		*/
			System.out.println(map.get("a"));
		}
		if(!flag){
			System.out.println("完蛋，找不到！");
		}else{
			System.out.println("遍历成功");
		}
		
	}
}