再送一波干货，测试2000线程并发下同时查询1000万条数据库表及索引优化

package insert;
 
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
 
public class ThreadToMysql extends Thread {
    public String teacherName;
    public String password;
    public ThreadToMysql(String teacherName, String password) {//构造函数传入要查询登录的老师姓名和密码
         
        this.teacherName=teacherName;
        this.password=password;
    }
     
    public void run() {
         String url = "jdbc:mysql://127.0.0.1/teacher"; 
         String name = "com.mysql.jdbc.Driver"; 
         String user = "root"; 
         String password = "123456"; 
        Connection conn = null; 
        try {
            Class.forName(name);
            conn = DriverManager.getConnection(url, user, password);//获取连接 
            conn.setAutoCommit(false);//关闭自动提交，不然conn.commit()运行到这句会报错
        } catch (ClassNotFoundException e1) {
            e1.printStackTrace();
        } catch (SQLException e) {
            e.printStackTrace();
        }
        if (conn!=null) {
            Long startTime=System.currentTimeMillis();//开始时间
            String sql="select id from t_teacher where t_name='"+teacherName+"' and t_password='"+password+"'";//SQL语句
            String id=null;
            try {
                Statement stmt=conn.createStatement();
                ResultSet rs=stmt.executeQuery(sql);//获取结果集
                if (rs.next()) {
                    id=rs.getString("id");
                }
                conn.commit();
                stmt.close();
                conn.close();
            } catch (SQLException e) {
                e.printStackTrace();
            }
                Long end=System.currentTimeMillis();
                System.out.println(currentThread().getName()+"  查询结果:"+id+"   开始时间:"+startTime+"  结束时间:"+end+"  用时:"+(end-startTime)+"ms");
             
             
        } else {
            System.out.println(currentThread().getName()+"数据库连接失败:");
        }
    }
     
}

package insert;
 
public class TestThreadToMysql {
 
    public static void main(String[] args) {
        for (int i = 1; i <=2000; i++) {
            String teacherName=String.valueOf(i);
            new ThreadToMysql(teacherName, "123456").start();
     
 
}

package insert;
 
public class TestThreadToMysql {
 
    public static void main(String[] args) {
        for (int i = 1; i <=200; i++) {
            String teacherName=String.valueOf(i);
            new ThreadToMysql(teacherName, "123456").start();
        }
    }
 
}

package insert;
 
public class TestThreadToMysql {
 
    public static void main(String[] args) {
        for (int i = 1; i <=2000; i++) {
            String teacherName=String.valueOf(i);
            new ThreadToMysql(teacherName, "123456").start();
        }
    }
 
}

package insert;
 
public class TestThreadToMysql {
 
    public static void main(String[] args) {
        for (int i = 1; i <=10000; i++) {
            String teacherName=String.valueOf(i);
            new ThreadToMysql(teacherName, "123456").start();
        }
    }
 
}