如下：其中添加/删除/修改只是sql字符串不同

//3.要执行的字符串
String sql="INSERT INTO t_student(NAME,age,email) VALUES('xxx','22','kangqing.37@gmail.com')";

//String sql="DELETE FROM t_student where id=2";

//String sql="UPDATE t_student set name='twzd',age='100',email='000' where id=7";

package com.hx.jdbc.connection;

import java.io.InputStream;

import java.sql.Connection;

import java.sql.DriverManager;

import java.sql.Statement;

import java.util.Properties;

import org.junit.Test;

import junit.framework.TestCase;

public class JDBCText extends TestCase {

    /**

     * 向数据库中添加一条数据

     *

     * statement:用于执行sql语句的对象

     * 用connection的createStatement()方法获取

     * 用executeUpdate(sql)执行sql语句

     * 注意：只能执行 insert,update,delect,不能执行select

     * @throws Exception

     */

    @Test

    public void testStatement() throws Exception{

        //1.调用getConnection2数据库连接方法

        Connection conn=null;

        Statement statement=null;

        try {

            conn=getConnection2();

            //3.要执行的字符串

            String sql="INSERT INTO t_student(NAME,age,email) VALUES('xxx','22','kangqing.37@gmail.com')";

            System.out.println(sql);

            //4.执行sql

            statement=conn.createStatement();

            statement.executeUpdate(sql);

        } catch (Exception e) {

            // TODO Auto-generated catch block

            e.printStackTrace();

        }finally{

            try {

                if(statement!=null)

                    statement.close();

            } catch (Exception e) {

                // TODO Auto-generated catch block

                e.printStackTrace();

            }finally{

                //2.关闭数据库

                if(conn!=null)

                    conn.close();

            }

        }

    }

    /**

     * 连接数据库的方法

     * @return

     * @throws Exception

     */

    @Test

    public Connection getConnection2() throws Exception{

        //1.创建数据库的4个字符串

        //2.创建Properties对象

        Properties pro=new Properties();

        //3.获取jdbc.pro对应的输入流

        InputStream in=

                this.getClass().getClassLoader().getResourceAsStream("jdbc.properties");

        //4.加载输入流

        pro.load(in);

        //5.具体决定4个字符串的值

        String driver=pro.getProperty("driver");

        String jdbcUrl=pro.getProperty("jdbcUrl");

        String user=pro.getProperty("user");

        String password=pro.getProperty("password");

        //6.加载数据库驱动程序

        Class.forName(driver);

        //7.通过DriverManager的getConnection()方法获取数据库连接

        Connection conn=DriverManager.getConnection(jdbcUrl, user, password);

        return conn;

    }

}

driver=com.mysql.jdbc.Driver

jdbcUrl=jdbc:mysql://localhost:3306/students

user=root

password=5678