List和Map结合

 利用Map来存放数据，利用List来存放Map，两者相互结合，下面是一个简单的例子。

ORM思想：对象关系映射

 

 ORM思想的简单实验：map表示一行数据，多行数据是多个map；将多个map放到list中

上代码：

import java.util.ArrayList;
import java.util.HashMap;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import java.util.Set;

/**
 * 利用容器存储整张表格
 * @author Administrator
 *
 */
public class TestStoreData0 {
	public static void main(String[] args) {
		Map<String,Object> row1 = new HashMap<>();
		row1.put("id", 1001);
		row1.put("name", "张三");	
		row1.put("salary", 20000);
		row1.put("入职日期", "2018.5.5");
		
		Map<String,Object> row2 = new HashMap<>();
		row2.put("id", 1002);
		row2.put("name", "李四");	
		row2.put("salary", 30000);
		row2.put("入职日期", "2005.4.4");
		
		Map<String,Object> row3 = new HashMap<>();
		row3.put("id", 1001);
		row3.put("name", "王五");	
		row3.put("salary", 3000);
		row3.put("入职日期", "2020.5.4");
		
		List<Map<String,Object>> table1 = new ArrayList<>(); 
		table1.add(row1);
		table1.add(row2);
		table1.add(row3);
		 
		for(Map<String,Object> row:table1) {
			Set<String> keyset = row.keySet();
			for(String key:keyset) {
				System.out.print(key+":"+row.get(key));
			}
			System.out.println();
		}
		
		for(Map<String,Object> row:table1) {
			Set<String> keyset = row.keySet();
			for(Iterator<String> iter = keyset.iterator();iter.hasNext();) {
				String temp = iter.next();
				System.out.print(temp+":"+row.get(temp));
			}
			System.out.println();
		}
		
		
		
	}
}