Treeset根据值进行大小的排序

package com.hh.racejob.oneoff.levelrank;

import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;
import java.util.TreeSet;

import com.hh.hhserver.extensions.db.DbManager;
import com.hh.hhserver.extensions.db.ResultObjectBuilder;
import com.hh.job.CustomStarter;
import com.hh.job.JobBase;

public  class GetLevelRank extends JobBase
{
private final static int DB_PART = 1000 * 10000;
private final static int DEFAULT_TABLE_PART = 100 * 10000;

private int partUnit = DEFAULT_TABLE_PART * 10;

private static String SELECT_USER_INFO ="SELECT UserId, Nickname,Level"
+ " FROM UserInfo{0} order by Level desc limit 100";

private static String INSERT="INSERT INTO RankingData VALUES(?,?,?,NOW())";

private static String DELETE="DELETE FROM RankingData WHERE NAME='level'";

private final static int TOPCOUNT=100;

private TreeSet<Content> set = new TreeSet<Content>();

public static void main(String[]args)
{
CustomStarter.main(new String[]{"GetLevelRank", "com.hh.racejob.oneoff.levelrank.GetLevelRank", null, null});
}

@Override
public void doJob(String[] arg0) {
//删除以前的废弃数据
DbManager.getWorkDb().executeCommand(DELETE);

//增加新的数据
for (int dbIndex = 0; dbIndex < DbManager.getPartDbCount(); dbIndex++)
{
int tableCount = DB_PART / partUnit;
for (int i = 0; i < tableCount; i++) {
int tableIndex = dbIndex * tableCount + i;
String newSQL = SELECT_USER_INFO.replace("{0}", String.valueOf(tableIndex));
newSQL = newSQL.replace("{1}", String.valueOf(tableIndex * partUnit));
newSQL = newSQL.replace("{2}", String.valueOf(tableIndex * partUnit + partUnit));

List<Content> contentList = DbManager.getPartitionDb(dbIndex).executeQuery_ObjectListEx(newSQL, Content.builder);

for(Content content : contentList){
if(content!=null)
{
content.setTime(String.valueOf(System.currentTimeMillis()));
set.add(content);
}
}
}
}

//得到要插入的100条RankData数据
ArrayList<Object[]>rankDatas=new ArrayList<>();
Iterator<Content> it = set.iterator();
int count=0;
while(it.hasNext()&&count<TOPCOUNT){
count++;

Content content=(Content) it.next();

RankData rankData=new RankData();
rankData.setContent(content.toString());
rankData.setDataKey(content.getUserId()+"");
rankData.setName("level");//固定
rankData.setAddDate(String.valueOf(System.currentTimeMillis()));

rankDatas.add(new Object[]{rankData.getName(),rankData.getDataKey(),rankData.getContent()});
}

//批量插入数据库
DbManager.getWorkDb().executeBatchCommandEx(INSERT, rankDatas);

}

@SuppressWarnings("rawtypes")
static class Content implements Comparable
{
public int userId;

public String nickName;

public int level;

public String time;

public Content()
{

}

public static  ResultObjectBuilder<Content>builder=new ResultObjectBuilder<Content>() {

@Override
public Content build(ResultSet rs) throws SQLException {
// TODO Auto-generated method stub
Content content=new Content();
content.userId=rs.getInt("UserId");
content.nickName=rs.getString("Nickname");
content.level=rs.getInt("Level");
return content;
}

};

public int getUserId() {
return userId;
}

public void setUserId(int userId) {
this.userId = userId;
}

public String getNickName() {
return nickName;
}

public void setNickName(String nickName) {
this.nickName = nickName;
}

public int getLevel() {
return level;
}

public void setLevel(int level) {
this.level = level;
}

public String getTime() {
return time;
}

public void setTime(String time) {
this.time = time;
}

@Override
public int compareTo(Object o) {
Content content=(Content)o;
if(level > content.getLevel()){
return -1;
} else if(level == content.getLevel()){
if(userId < content.getUserId()){
return -1;
} else{
return 1;
}
} else {
return 1;
}

}

public String toString()
{
return userId+":"+nickName+":"+level+":"+time;
}
}

class RankData
{
public String Name;

public String DataKey;

public String Content;

public String AddDate;

public RankData()
{

}

public String getName() {
return Name;
}

public void setName(String name) {
Name = name;
}

public String getDataKey() {
return DataKey;
}

public void setDataKey(String dataKey) {
DataKey = dataKey;
}

public String getContent() {
return Content;
}

public void setContent(String content) {
Content = content;
}

public String getAddDate() {
return AddDate;
}

public void setAddDate(String addDate) {
AddDate = addDate;
}
}
}

类Content中，当level一样大的时候，uid小的排序在前面，否则相反；

Compareto中，不要返回0，如果直接返回result可能会出现0的状况，一般返回值的含义如下：

1.返回 1 那么当前的值会排在 被比较者 后面。

2.返回 0 那么当前的值【不会被加入到 TreeSet 中】，因为当前的值【被认为是跟现有的某一个值相等】。

3.返回 -1 会被添加到 被比较者 的前边。
总结：
主要需求：从十张表中，选出level的前 100名；

主要思路是：从十张表中，每张表拿出前100名用户，放在treeset里面，然后交给treeset的compare进行比较，就可以得到了