只需3步。

1、导入mysql的jar包。

略

2、封装配置文件db.properties

driverClass = com.mysql.jdbc.Driver

url = jdbc:mysql:///databaseName?useUnicode=true&characterEncoding=utf8

user = root

password = 123

把数据库驱动和一些数据库参数封装到配置文件，做到随时更换数据库。

3、封装连接代码

/**

* Created by youxuan on 2017/1/15 0015.

* JDBC工具类

*/

public class JDBCUtil {

private static final String driverClass;

private static final String url;

private static final String user;

private static final String password;

static {

try {

InputStream in = JDBCUtil.class.getClassLoader().getResourceAsStream("db.properties");

Properties pr = new Properties();

pr.load(in);

driverClass = pr.getProperty("driverClass");

url = pr.getProperty("url");

user = pr.getProperty("user");

password = pr.getProperty("password");

Class.forName(driverClass);

} catch (Exception e) {

throw new ExceptionInInitializerError(e);

}

}

public static Connection getConnection() throws SQLException {

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

return conn;

}

/**

*清理数据库资源

* @param rs

* @param stat

* @param conn

*/

public static void release(ResultSet rs, Statement stat,Connection conn){

try {

if (rs != null) {

rs.close();

}

rs = null;

if(stat != null){

stat.close();

}

stat = null;

if(conn!=null){

conn.close();

}

conn = null;

}catch (Exception e){

e.printStackTrace();

}

}

}

4、连接测试

public void text1(){

Connection conn = null;

Statement stmt = null;

ResultSet rs = null;

try{

conn = JDBCUtil.getConnection();

stmt = conn.createStatement();

rs = stmt.executeQuery(" select * from user ");

while(rs.next()){

.......

}

}catch(Exception e){

throw new RuntimeException(e);

}finally{

JDBCUtil.release(rs, stmt, conn); //关闭数据库资源

}

}