一、单线程（单条循环）插入50000条记录：
每执行一次就要访问一次数据库
import java.sql.Connection;import java.sql.DriverManager;import java.sql.ResultSet;import java.sql.SQLException;import java.sql.Statement;public class Test {public static void main(String[] args) {Connection conn;Statement stmt;ResultSet rs = null;String url = "jdbc:sqlserver://localhost:1433;DatabaseName=test;";String sql = "insert into student(name,age) values('wang',12)";try {// 连接数据库conn = DriverManager.getConnection(url, "sa", "123456");// 建立Statement对象stmt = conn.createStatement();/*** Statement createStatement() 创建一个 Statement 对象来将 SQL 语句发送到数据库。*/// 执行数据库查询语句long starttime=System.currentTimeMillis();for(int i=0; i<50000;i++){stmt.executeUpdate(sql);}long spendtime=System.currentTimeMillis()-starttime;System.out.println( "单线程批处理花费时间:"+spendtime);/*** ResultSet executeQuery(String sql) throws SQLException 执行给定的 SQL* 语句，该语句返回单个 ResultSet 对象*/if (rs != null) {rs.close();rs = null;}if (stmt != null) {stmt.close();stmt = null;}if (conn != null) {conn.close();conn = null;}} catch (SQLException e) {e.printStackTrace();System.out.println("数据库连接失败");} } }
二、单线程（批处理）插入50000条记录：
stmt.addBatch()：把要执行的多条sql语句放在一起，通过stmt.executeBatch()只访问一次数据库，就前面的多条sql语句一起插入
import java.sql.Connection;import java.sql.DriverManager;import java.sql.ResultSet;import java.sql.SQLException;import java.sql.Statement;public class Test {public static void main(String[] args) {Connection conn;Statement stmt;ResultSet rs = null;String url = "jdbc:sqlserver://localhost:1433;DatabaseName=test;";String sql = "insert into student(name,age) values('wang',12)";try {// 连接数据库conn = DriverManager.getConnection(url, "sa", "123456");// 建立Statement对象stmt = conn.createStatement();/*** Statement createStatement() 创建一个 Statement 对象来将 SQL 语句发送到数据库。*/// 执行数据库查询语句long starttime=System.currentTimeMillis();for(int i=0; i<50000;i++){stmt.addBatch("insert into student(name,age) values('wang',12)"); }stmt.executeBatch();long spendtime=System.currentTimeMillis()-starttime;System.out.println( "单线程批处理花费时间:"+spendtime);/*** ResultSet executeQuery(String sql) throws SQLException 执行给定的 SQL* 语句，该语句返回单个 ResultSet 对象*/if (rs != null) {rs.close();rs = null;}if (stmt != null) {stmt.close();stmt = null;}if (conn != null) {conn.close();conn = null;}} catch (SQLException e) {e.printStackTrace();System.out.println("数据库连接失败");} } }
执行后会发现：时间缩短很多
三、多线程（单条循环）插入50000条记录：
启动5个线程，每个线程插入10000条记录
import java.sql.Connection;import java.sql.DriverManager;import java.sql.SQLException;import java.sql.Statement;import java.util.UUID;import java.util.concurrent.CountDownLatch;public class InsertTest {private String url="jdbc:sqlserver://localhost:1433;DatabaseName=test;";private String user="sa";private String password="123456";public Connection getConnect(){Connection con = null;try {Class.forName("com.microsoft.sqlserver.jdbc.SQLServerDriver");con=DriverManager.getConnection(url, user, password);} catch (Exception e) {e.printStackTrace();}return con;}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() {@Overridepublic void run() {Connection con=getConnect();try {Statement st=con.createStatement();for(int i=1;i<=10000;i++){//st.addBatch("insert into student(name,age) values('wang',12)");st.executeUpdate("insert into student(name,age) values('wang',12)");}//st.executeBatch();cdl.countDown();} catch (Exception e) {}finally{try {con.close();} catch (SQLException 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 (InterruptedException e) {e.printStackTrace();}}public static void main(String[] args) throws Exception {InsertTest ti=new InsertTest();ti.multiThreadImport(5);}}
四、多线程（批处理）插入50000条记录：
启动5个线程
import java.sql.Connection;import java.sql.DriverManager;import java.sql.SQLException;import java.sql.Statement;import java.util.UUID;import java.util.concurrent.CountDownLatch;public class InsertTest {private String url="jdbc:sqlserver://localhost:1433;DatabaseName=test;";private String user="sa";private String password="Rfid123456";public Connection getConnect(){Connection con = null;try {Class.forName("com.microsoft.sqlserver.jdbc.SQLServerDriver");con=DriverManager.getConnection(url, user, password);} catch (Exception e) {e.printStackTrace();}return con;}public void multiThreadImport( final int ThreadNum){final CountDownLatch cdl= new CountDownLatch(ThreadNum);//定义线程数量long starttime=System.currentTimeMillis();for(int k=1;k<=ThreadNum;k++){new Thread(new Runnable() {@Overridepublic void run() {Connection con=getConnect();try {Statement st=con.createStatement();for(int i=1;i<=50000/ThreadNum;i++){st.addBatch("insert into student(name,age) values('wang',12)");if(i%500 == 0){st.executeBatch();}}cdl.countDown();//执行完一个线程，递减1} catch (Exception e) {}finally{try {con.close();} catch (SQLException e) {e.printStackTrace();}}}}).start();}try {cdl.await();//前面线程没执行完，其他线程等待，不往下执行long spendtime=System.currentTimeMillis()-starttime;System.out.println( ThreadNum+"个线程花费时间:"+spendtime);} catch (InterruptedException e) {e.printStackTrace();}}public static void main(String[] args) throws Exception {InsertTest ti=new InsertTest();ti.multiThreadImport(5);}}
CountDownLatch：这个类能够使一个线程等待其他线程完成各自的工作后再执行。
（1）它通过一个计数器来实现的，计数器的初始值为线程的数量。
CountDownLatch cdl= new CountDownLatch(ThreadNum)
（2）每当一个线程完成了自己的任务后，计数器的值就会减1。当计数器值到达0时，它表示所有的线程已经完成了任务，
cdl.countDown();
（3）然后在闭锁上等待的线程就可以恢复执行任务。
cdl.await();
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