public void testJDBCTransaction() {
Connection conn = null;
try {
// 1.獲取數(shù)據(jù)庫連接
conn = JDBCUtils.getConnection();
// 2.開啟事務(wù)
conn.setAutoCommit(false);
// 3.進(jìn)行數(shù)據(jù)庫操作

// 4.若沒有異常，則提交事務(wù)
conn.commit();
} catch (Exception e) {
e.printStackTrace();
// 5.若有異常，則回滾事務(wù)
try {
conn.rollback();
} catch (SQLException e1) {
e1.printStackTrace();
}} finally {
JDBCUtils.close(null, null, conn); }  }

package com.company.jdbcDemo;

import com.company.jdbcDemo.JDBCUtils;

import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.SQLException;

/*
    AA給CC轉(zhuǎn)賬1000
    AA 2000
    CC 2000

        try{
           開啟事務(wù)
           AA -= 1000
           System.out.println(1/0);
           CC += 1000
           提交(一旦提交數(shù)據(jù)不能再回滾（撤銷）)
        }catch(Exception e){
        事務(wù)回滾（撤銷）
        }

    CREATE TABLE account(
    NAME VARCHAR(20),
    balance INT
    )

 */
public class AccountDemo {

    public static void main(String[] args) throws SQLException {
        //1.獲取數(shù)據(jù)庫連接對象
        Connection connection = JDBCUtils.getConnection();
        PreparedStatement ps = null;
        try {
            //2.開啟事物--禁止自動提交
            connection.setAutoCommit(false);
            //-------------------------------------------------------------------
            //3.做具體的操作---執(zhí)行sql語句
            //預(yù)編譯
            String sql = "update account set balance=? where name=?";
            ps = connection.prepareStatement(sql);

            //給占位符賦值
            ps.setInt(1, 1000);
            ps.setString(2, "aa");
            //執(zhí)行sql
            ps.executeUpdate();

            System.out.println(1 / 0);

            //給占位符賦值
            ps.setInt(1, 3000);
            ps.setString(2, "cc");
            //執(zhí)行sql
            ps.executeUpdate();
            //-------------------------------------------------------------------
            //4.事務(wù)提交
            connection.commit();
        }catch (Exception e){
            e.printStackTrace();
            //5.事務(wù)回滾
            connection.rollback();
        }finally {
            //6.允許自動提交
            connection.setAutoCommit(true);
            //7.關(guān)閉資源----最后關(guān)閉資源
            JDBCUtils.close(ps,connection);

        }
    }
}

//1、創(chuàng)建數(shù)據(jù)源（數(shù)據(jù)庫連接池）對象
DruidDataSource ds =new DruidDataSource();
//2、設(shè)置參數(shù)
//(1)設(shè)置基本參數(shù)
ds.setDriverClassName("com.mysql.jdbc.Driver");
ds.setUrl("jdbc:mysql://localhost:3306/test");
ds.setUsername("root");
ds.setPassword("mysql123");
//3、獲取連接
Connection conn = ds.getConnection();
//如果這里沒有關(guān)閉，就相當(dāng)于沒有還
conn.close();

// 創(chuàng)建配置文件druid.properties
url=jdbc:mysql://localhost:3306/0319db ?rewriteBatchedStatements=true
username=root
password=123456
driverClassName=com.mysql.jdbc.Driver

代碼如下：
Properties pro = new Properties();
pro.load(TestDruid2.class.getClassLoader().getResourceAsStream("druid.properties"));
DataSource ds=
		DruidDataSourceFactory.createDataSource(pro);
Connection conn = ds.getConnection();

// druid.properties內(nèi)容
url=jdbc:mysql://localhost:3306/demo
username=root
password=123321
driverClassName=com.mysql.jdbc.Driver

package com.company.jdbc2;

import com.company.jdbc.JDBCUtils;
import org.apache.commons.dbutils.QueryRunner;
import org.apache.commons.dbutils.handlers.BeanHandler;
import org.apache.commons.dbutils.handlers.BeanListHandler;
import org.junit.Test;

import java.sql.SQLException;
import java.util.List;

/*
    通過使用DBUtils工具類實(shí)現(xiàn)增，刪，改，查的操作
 */
public class DBUtilsDemo {

    @Test
    public void test() throws SQLException {
        //1.創(chuàng)建操作對象
        QueryRunner queryRunner = new QueryRunner();
        //2.增，刪，改是一個方法
        /*
            update(Connection conn, String sql, Object param)
            conn : 連接對象
            sql : sql語句
            param : 給占位符賦值的內(nèi)容
         */
        String sql = "insert into student(sid,sname,sage) values(?,?,?)";
        //返回值 ：有幾條數(shù)據(jù)受到影響
        int i = queryRunner.update(JDBCUtils.getConnection(),
                sql, 10, "kongkong", 18);
        System.out.println("有" + i + "條數(shù)據(jù)受到影響");
    }

    @Test
    public void test2() throws SQLException {
        QueryRunner queryRunner = new QueryRunner();
        /*
        query(Connection conn, String sql, ResultSetHandler<T> rsh, Object... params)
        conn : 連接對象
        sql : sql語句

         */
        String sql = "select sid a,sname,sage from student where sid=?";
        //注意：類中的屬性名一定要和字段名相同。如果不相同則需要在sql語句中使用別名
//        Student student = queryRunner.query(JDBCUtils.getConnection(), sql,
//                new BeanHandler<Student>(Student.class), 10);




        sql = "select sid a,sname,sage from student";
        List<Student> list = queryRunner.query(JDBCUtils.getConnection(), sql,
                new BeanListHandler<Student>(Student.class));

       for (Student s : list) {
           System.out.println(s);
       }
    }

}

jdbc:mysql://localhost:3306/Demo?rewriteBatchedStatements=true

package com.company.jdbc3;

import com.company.jdbc.JDBCUtils;
import org.junit.Test;

import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.SQLException;

/*
    批處理：
 */
public class BatchDemo {

    /*
        使用批處理：
            1.mysql驅(qū)動包的版本必須為5.1.3x  才支持批處理
            2.在url連接中添加如下參數(shù)
                    jdbc:mysql://localhost:3306/Demo?rewriteBatchedStatements=true
            3.使用一些API：
                //添加到批處理中
                ps.addBatch();
                //執(zhí)行批處理
                ps.executeBatch();
                //清空批處理
                ps.clearBatch();
     */
    @Test
    public void test2() throws SQLException {
        //1.獲取數(shù)據(jù)庫連接
        Connection connection = JDBCUtils.getConnection();
        //2.預(yù)編譯
        PreparedStatement ps = connection.prepareStatement(
                "insert into student(sid,sname,sage) values(?,?,?)");
        //3.給占位符賦值
        for (int i = 1; i <= 100000 ; i++) {
            ps.setInt(1,i);
            ps.setString(2,"aaa"+i);
            ps.setInt(3,i);
            //添加到批處理中
            ps.addBatch();

            if (i % 1000 == 0){
                //執(zhí)行sql
                ps.executeBatch();//執(zhí)行批處理
                //清空批處理
                ps.clearBatch();
            }

        }
        //4.關(guān)資源
        JDBCUtils.close(ps,connection);
    }

    @Test
    public void test() throws SQLException {
        //1.獲取數(shù)據(jù)庫連接
        Connection connection = JDBCUtils.getConnection();
        //2.預(yù)編譯
        PreparedStatement ps = connection.prepareStatement(
                "insert into student(sid,sname,sage) values(?,?,?)");
        //3.給占位符賦值
        for (int i = 1; i <= 100000 ; i++) {
            ps.setInt(1,i);
            ps.setString(2,"aaa"+i);
            ps.setInt(3,i);
            //執(zhí)行sql
            ps.executeUpdate();
        }
        //4.關(guān)資源
        JDBCUtils.close(ps,connection);
    }
}