多线程

Posted 2020-09-29 jassy

import java.util.concurrent.CountDownLatch;

public class ThreadTest {
    public static void main(String[] args) {
        ThreadTest ti=new ThreadTest();
        ti.multiThreadImport(1);
        ti.multiThreadImport(10);
        System.out.println("本机CPU数:"+Runtime.getRuntime().availableProcessors());
    }
    public void multiThreadImport(final int ThreadNum){
        final CountDownLatch cdl= new CountDownLatch(ThreadNum);
        long starttime=System.currentTimeMillis();
        for(int k=1;k<=ThreadNum;k++){
            new Thread(new Runnable() {
                @Override
                public void run() {
                    try {
                        System.out.println("多线程"+ThreadNum);
                        cdl.countDown();
                    } catch (Exception e) {
                        e.printStackTrace();
                    }
                }
            }).start();
        }
        try {
            cdl.await();
            long spendtime=System.currentTimeMillis()-starttime;
            System.out.println( ThreadNum+"个线程花费时间:"+spendtime);
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}

 多线程插入数据

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.SQLException;
import java.util.UUID;
import java.util.concurrent.CountDownLatch;

public class ThreadTest {
    static Connection conn;
    public void multiThreadImport( final int ThreadNum){
        final CountDownLatch cdl= new CountDownLatch(ThreadNum);
        long starttime=System.currentTimeMillis();
        for(int k=1;k<=ThreadNum;k++){
            new Thread(new Runnable() {
                @Override
                public void run() {
                   // 获得连接
                try {
                    conn=getConnect();
                } catch (Exception e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                }
                //插入500/线程数条数据
                for(int i=1;i<=10/ThreadNum;i++){
                    String uuid=UUID.randomUUID().toString().replace("-", "");
                    try {
                        //Statement statement = conn.createStatement();
                        PreparedStatement ps = conn.prepareStatement("insert into FILEINFO(id) values (?)");
                        //statement.executeUpdate(sql);
                        //ps.addBatch("insert into demo(name,adress) values(‘"+uuid+"‘,‘"+uuid+"‘)");
                        ps.setString(1, uuid);
                        ps.executeUpdate();
                        if(i%10==0){
                            ps.executeBatch(); //10条执行一次
                            System.out.println("INSERT into FILEINFO(id) values " + uuid);
                        }
                    } catch (SQLException e) {
                        // TODO Auto-generated catch block
                        e.printStackTrace();
                    }
                            
                }
                cdl.countDown();
            }
        }).start();
    }
        try {
            cdl.await();
            long spendtime=System.currentTimeMillis()-starttime;
            System.out.println( ThreadNum+"个线程花费时间:"+spendtime);
        } catch (InterruptedException e) {
            e.printStackTrace();
        }


    }

    public Connection getConnect(){
        Connection con = null;
        String url = "";
        String user = "";
        String password = "";
        
        
         try {
            Class.forName("oracle.jdbc.driver.OracleDriver");
            if(MyFile.getInfo("d:/njdx.ini").length()>0){
                for(int i=0;i<MyFile.getInfo("d:/njdx.ini").split(",").length;i++){
                    url = MyFile.getInfo("d:/njdx.ini").split(",")[0];//数据库连接地址
                    user = MyFile.getInfo("d:/njdx.ini").split(",")[1];//数据库用户名
                    password = MyFile.getInfo("d:/njdx.ini").split(",")[2];//数据库密码                    
                }                
            }    
            con=DriverManager.getConnection(url, user, password);
        } catch (Exception e) {
            e.printStackTrace();
        }
         return con;
    }
    public static void main(String[] args) throws Exception {
        ThreadTest ti=new ThreadTest();
        ti.multiThreadImport(1);
        System.out.println("+++1个线程结束+++");
        ti.multiThreadImport(2);
        System.out.println("+++2个线程结束+++");
        ti.multiThreadImport(8);
        System.out.println("+++8个线程结束+++");
        ti.multiThreadImport(10);
        System.out.println("+++10个线程结束+++");
        System.out.println("笔记本CPU数:"+Runtime.getRuntime().availableProcessors());
   
    }
}