ArrayList 转换的问题
这样的一个结果集:
name date total
a 3 100
a 4 200
a 5 300
a 6 400
b 3 500
b 4 600
b 5 700
b 6 800
(也即,SQL group by name ,date)
结果行以Map封装存放到ArrayList 对象,如:
ArrayList resultList =new ArrayList();
Map M1=new HashMap();
M1.put("name","a");
M1.put("date","2");
M1.put("total","800");
....
Map Mn=new HashMap();
Mn.put("name","b");
Mn.put("date","2");
Mn.put("total","100");
resultList.add(M1);
..
resultList.add(Mn);
现需要将resultList转换为如下形式:
name date total
a new int[]{3,4,5,6} new int[]{100,200,300,400}
b new int[]{3,4,5,6} new int[]{500,600,700,800}
也即,只要name相同,date,total转换为整形数组,转换后的ArrayList每一行也是以Map对象封装
如何实现?