Question

java多线程更新数据库批量的数据信息吗?怎么实现?

谢谢 !

Answer 1

//将数据库中的数据条数分段
public void division(){
//获取要导入的总的数据条数
String sql3="SELECT count(*) FROM [CMD].[dbo].[mycopy1]";
try {
pss=cons.prepareStatement(sql3);
rss=pss.executeQuery();

while(rss.next()){
System.out.println("总记录条数:"+rss.getInt(1));
sum=rss.getInt(1);
}
//每30000条记录作为一个分割点
if(sum>=30000){
n=sum/30000;
residue=sum%30000;
}else{
residue=sum;
}

System.out.println(n+" "+residue);

} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}

}
线程类
public MyThread(int start,int end) {
this.end=end;
this.start=start;
System.out.println("处理掉余数");
try {

System.out.println("--------"+Thread.currentThread().getName()+"------------");
Class.forName(SQLSERVERDRIVER);
System.out.println("加载sqlserver驱动...");
cons = DriverManager.getConnection(CONTENTS,UNS,UPS);
stas = cons.createStatement();
System.out.println("连接SQLServer数据库成功！！");

System.out.println("加载mysql驱动.....");
Class.forName(MYSQLDRIVER);
con = DriverManager.getConnection(CONTENT,UN,UP);
sta = con.createStatement();
// 关闭事务自动提交
con.setAutoCommit(false);
System.out.println("连接mysql数据库成功！！");

} catch (Exception e) {
e.printStackTrace();
}
// TODO Auto-generated constructor stub
}

public ArrayList<Member> getAll(){
Member member;
String sql1="select * from (select row_number() over (order by pmcode) as rowNum,*" +
" from [CMD].[dbo].[mycopy1]) as t where rowNum between "+start+" and "+end;
try {
System.out.println("正在获取数据...");
allmembers=new ArrayList();
rss=stas.executeQuery(sql1);
while(rss.next()){
member=new Member();
member.setAddress1(rss.getString("address1"));
member.setBnpoints(rss.getString("bnpoints"));
member.setDbno(rss.getString("dbno"));
member.setExpiry(rss.getString("expiry"));
member.setHispoints(rss.getString("hispoints"));
member.setKypoints(rss.getString("kypoints"));
member.setLevels(rss.getString("levels"));
member.setNames(rss.getString("names"));
member.setPmcode(rss.getString("pmcode"));
member.setRemark(rss.getString("remark"));
member.setSex(rss.getString("sex"));
member.setTelephone(rss.getString("telephone"));
member.setWxno(rss.getString("wxno"));
member.setPmdate(rss.getString("pmdate"));
allmembers.add(member);
// System.out.println(member.getNames());
}
System.out.println("成功获取sqlserver数据库数据！");
return allmembers;

} catch (SQLException e) {
// TODO Auto-generated catch block
System.out.println("获取sqlserver数据库数据发送异常！");
e.printStackTrace();
}
try {
rss.close();
stas.close();
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
return null;
}

public void inputAll(ArrayList<Member> allmembers){
System.out.println("开始向mysql中写入");
String sql2="insert into test.mycopy2 values (?,?,?,?,?,?,?,?,?,?,?,?,?,?)";
try {
ps=con.prepareStatement(sql2);
System.out.println("-------------------------等待写入数据条数: "+allmembers.size());
for(int i=0;i<allmembers.size();i++){
ps.setString(1, allmembers.get(i).getPmcode());
ps.setString(2, allmembers.get(i).getNames());
//System.out.println(allmembers.get(i).getNames());
ps.setString(3, allmembers.get(i).getSex());
ps.setString(4, allmembers.get(i).getTelephone());
ps.setString(5, allmembers.get(i).getAddress1());
ps.setString(6, allmembers.get(i).getPmdate());
ps.setString(7, allmembers.get(i).getExpiry());
ps.setString(8, allmembers.get(i).getLevels());
ps.setString(9, allmembers.get(i).getDbno());
ps.setString(10, allmembers.get(i).getHispoints());
ps.setString(11, allmembers.get(i).getBnpoints());
ps.setString(12, allmembers.get(i).getKypoints());
ps.setString(13, allmembers.get(i).getWxno());
ps.setString(14, allmembers.get(i).getRemark());
//插入命令列表
//ps.addBatch();
ps.executeUpdate();
}
//ps.executeBatch();
con.commit();

ps.close();
con.close();
this.flag=false;
System.out.println(Thread.currentThread().getName()+"--->OK");
} catch (SQLException e) {
// TODO Auto-generated catch block
System.out.println("向mysql中更新数据时发生异常！");
e.printStackTrace();
}
}
@Override
public void run() {
// TODO Auto-generated method stub
while(true&&flag){
this.inputAll(getAll());
}
}

Answer 2

1、把你数据库的表，对应写成一个java bean，假如该类名为Message。
2、写好一个MessageDao的类，里面包含有你对数据库的操作等方法，如:
public static boolean update(Message m){}
3、写一个处理线程，如:HandleThread.java
4、写一个处理的类，调用HandleThread线程。
HandleThread.java
public class HandleThread implements Runnable{
private Handle handle;
public HandleThread(Handle h){
this.handle=h;
}
public void run(){
Message msg=handle.getNext();

while(msg!=null){

myHandle(msg);
msg=handle.getNext();
}
}

private boolean myHandle(Message msg){
//在这里写你要对数据库进行的操作。调用MessageDao里面的方法
}
}

Hanlde.java
public class Handle{
private ArrayList<Message> list=new ArrayList<Message>();

public int next=0;
public void initList(){

//在这里，调用list.add(Message);的方法，把你需要进行批处理的Message放进去
}

private synchronized Message getNext(){

if(next>=list.size()) return null;
next++;
return list.get(next-1);
}//同步，防止多次处理

public void handle(){

next=0;
initList();
int threadQuantity=3;//定义处理的线程个数
for(int i=0;i<threadQuantity;i++){
new Thread(new HandleThread(this)).start();
}
}//开始处理

public static void main(String args[]){

new Handle().handle();
}
}

//有什么不懂的就追问吧。。

Answer 3

分出小批来，不同的线程，更新不同的小批