java的jdbc连接数据库，读取表中数据

连接数据库操作步骤如下

1. 架包 jar
2. 建表
3. 源码解析

1:架包 jar
根据自己本版本选择正确jar包，本例采用maven 管理局，在pom.xml 中添加如下代码，自动下载架包

	<dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>5.1.25</version>
        </dependency>

2:建表

DROP TABLE IF EXISTS `tb_user`;
CREATE TABLE `tb_user` (
  `id` int(11) NOT NULL AUTO_INCREMENT,
  `username` varchar(20) DEFAULT NULL,
  `password` varchar(20) DEFAULT NULL,
  `head_root` varchar(80) DEFAULT NULL,
  `realname` varchar(10) DEFAULT NULL,
  `netname` varchar(20) DEFAULT NULL,
  `email` varchar(20) DEFAULT NULL,
  `age` int(10) DEFAULT NULL,
  `sex` varchar(2) DEFAULT NULL,
  `birth_year` int(10) DEFAULT NULL,
  `birth_month` int(10) DEFAULT NULL,
  `birth_day` int(10) DEFAULT NULL,
  `addressid` int(11) DEFAULT NULL COMMENT '地址详细信息',
  `tall` double(11,0) DEFAULT NULL,
  `user_grade` varchar(10) DEFAULT NULL,
  `income` double(20,0) DEFAULT NULL,
  `marry` varchar(5) DEFAULT NULL,
  `marrySex` varchar(2) DEFAULT NULL,
  `gexingmsg` varchar(80) DEFAULT NULL,
  `vip` int(10) DEFAULT NULL,
  `money` int(11) DEFAULT NULL,
  `renzheng` varchar(10) DEFAULT NULL,
  `fenlei` varchar(10) DEFAULT NULL,
  `biaoqian` int(11) DEFAULT NULL,
  `user_black` int(11) DEFAULT NULL,
  `user_youhui` int(11) DEFAULT NULL,
  `user_work` varchar(10) DEFAULT NULL,
  `user_home` int(11) DEFAULT NULL,
  `user_car` int(11) DEFAULT NULL,
  PRIMARY KEY (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=31 DEFAULT CHARSET=utf8;

3:源码

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;

/**
 * @author Evan
 *
 */
public class JDBCTest {
    public static void main(String[] args) throws Exception {
        Connection connection = null;
        PreparedStatement prepareStatement = null;
        ResultSet rs = null;

        try {
            // 加载驱动
            Class.forName("com.mysql.jdbc.Driver");
            // 获取连接
            String url = "jdbc:mysql://127.0.0.1:3306/test";
            String user = "root";
            String password = "asplover";
            connection = DriverManager.getConnection(url, user, password);
            // 获取statement，preparedStatement
            String sql = "select * from tb_user where id=?";
            prepareStatement = connection.prepareStatement(sql);
            // 设置参数
            prepareStatement.setLong(1, 1);
            // 执行查询
            rs = prepareStatement.executeQuery();
            // 处理结果集
            while (rs.next()) {
                System.out.println("用户名："+rs.getString("userName"));
                System.out.println("密码为："+rs.getString("password"));

            }
        } finally {
            // 关闭连接，释放资源
            if (rs != null) {
                rs.close();
            }
            if (prepareStatement != null) {
                prepareStatement.close();
            }
            if (connection != null) {
                connection.close();
            }
        }
    }
}