1、初始生成字符串的代码程序：

package com.map.test;

import java.util.ArrayList;

import java.util.Collections;

import java.util.HashMap;

import java.util.List;

import java.util.Map;

public class Test {

/**

* @param args

*/

public static List> maps = new ArrayList>();

static{

Map m1 = new HashMap();

m1.put("total", "10");

m1.put("createTime", "2014-10-18");

maps.add(m1);

Map m2 = new HashMap();

m2.put("total", "20");

m2.put("createTime", "2014-10-15");

maps.add(m2);

Map m3 = new HashMap();

m3.put("total", "30");

m3.put("createTime", "2014-10-19");

maps.add(m3);

Map m4 = new HashMap();

m4.put("total", "40");

m4.put("createTime", "2014-10-17");

maps.add(m4);

Map m5 = new HashMap();

m5.put("total", "50");

m5.put("createTime", "2014-10-16");

maps.add(m5);

Map m6 = new HashMap();

m6.put("total", "60");

m6.put("createTime", "2014-10-20");

maps.add(m6);

Map m7 = new HashMap();

m7.put("total", "70");

m7.put("createTime", "2014-10-21");

maps.add(m7);

}

2、main方法调用拼接的方法

/**

*

* @param args main方法调用拼接的方法

*/

public static void main(String[] args) {

// TODO Auto-generated method stub

sortList(maps);

getTimeString();

getTotalString();

}

3、将程序进行排序

package com.map.test;

import java.text.ParseException;

import java.text.SimpleDateFormat;

import java.util.Comparator;

import java.util.Date;

import java.util.Map;

public class ReportCompare implements Comparator> {

@Override

public int compare(Map o1, Map o2) {

String o1Time = o1.get("createTime");

String o2Time = o2.get("createTime");

SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");

try {

Date o1D = sdf.parse(o1Time);

Date o2D = sdf.parse(o2Time);

if (o1D.before(o2D)) {

return -1;

}else if (o1D.equals(o2D)) {

return 0;

}else if (o1D.after(o2D)) {

return 1;

}

} catch (ParseException e) {

// TODO Auto-generated catch block

e.printStackTrace();

}

return 2;

}

}

4、拼接字符串

public static void getTimeString() {

StringBuffer sb = new StringBuffer("[");

for (Map map : maps) {

sb.append("'"+map.get("createTime")+"',");

}

sb.deleteCharAt(sb.length()-1);

sb.append("]");

System.out.println(sb.toString());

}

public static void getTotalString() {

StringBuffer sb = new StringBuffer("[");

for (Map map : maps) {

sb.append(map.get("total")+",");

}

sb.deleteCharAt(sb.length()-1);

sb.append("]");

System.out.println(sb.toString());

}

public static List> sortList(List> maps){

Collections.sort(maps, new ReportCompare());

return maps;

}

}