JDBC编程之优化

driver=com.mysql.jdbc.Driver

dburl=jdbc\:mysql\://localhost\:3306/mytest

user=root

password=

 package com.test.util;

 import java.io.InputStream;

 import java.sql.Connection;

 import java.sql.DriverManager;

 import java.util.Properties;

 public class ConnectionFactory {

     private static String driver;

     private static String dburl;

     private static String user;

     private static String password;

     private static final ConnectionFactory factory = new ConnectionFactory();

     private Connection conn;

     static{

         Properties prop = new Properties();

         try{

             InputStream in = ConnectionFactory.class.getClassLoader()

                     .getResourceAsStream("dbconfig.properties");

             prop.load(in);

         }catch(Exception e){

             System.out.println("配置文件读取错误");

         }

         driver = prop.getProperty("driver");

         dburl = prop.getProperty("dburl");

         user = prop.getProperty("user");

         password = prop.getProperty("password");

     }

     private ConnectionFactory(){

     }

     public static ConnectionFactory getInstance(){

         return factory;

     }

     public Connection makeConnection(){

         try{

             Class.forName(driver);

             conn = DriverManager.getConnection(dburl,user,password);

         }catch(Exception e){

             e.printStackTrace();

         }

         return conn;

     }

 }

 package com.test.entity;

 public abstract class IdEntity {

     protected int id;

     public int getId(){

         return id;

     }

     public void setId(int id){

         this.id = id;

     }

 }

 package com.test.entity;

 public class User extends IdEntity {

     private String name;

     private String password;

     public String getName() {

         return name;

     }

     public void setName(String name) {

         this.name = name;

     }

     public String getPassword() {

         return password;

     }

     public void setPassword(String password) {

         this.password = password;

     }

     @Override

     public String toString() {

         return "User [name=" + name + ", password=" + password + ", id=" + id

                 + "]";

     }

 }

 package com.test.entity;

 public class Address extends IdEntity{

     private String address;

     private int userid;

     public String getAddress() {

         return address;

     }

     public void setAddress(String address) {

         this.address = address;

     }

     public int getUserid() {

         return userid;

     }

     public void setUserid(int userid) {

         this.userid = userid;

     }

     @Override

     public String toString() {

         return "Address [address=" + address + ", userid=" + userid + ", id="

                 + id + "]";

     }

 }

 package com.test.dao;

 import java.sql.Connection;

 import java.sql.SQLException;

 import com.test.entity.User;

 public interface UserDao {

     public void save(Connection conn,User user)throws SQLException;

     public void update(Connection conn,int id,User user) throws SQLException;

     public void delete(Connection conn,User user)throws SQLException;

 }

 package com.test.dao.impl;

 import java.sql.Connection;

 import java.sql.PreparedStatement;

 import java.sql.SQLException;

 import com.test.dao.UserDao;

 import com.test.entity.User;

 public class UserDaoImpl implements UserDao{

     @Override

     public void save(Connection conn, User user) throws SQLException {

         PreparedStatement ps = conn.prepareCall("insert into person(name,password) values(?,?)");

         ps.setString(, user.getName());

         ps.setString(, user.getPassword());

         ps.execute();

     }

     @Override

     public void update(Connection conn, int id, User user) throws SQLException {

         String updateSql ="update person set name= ?,password=? where id =?";

         PreparedStatement ps = conn.prepareStatement(updateSql);

         ps.setString(, user.getName());

         ps.setString(, user.getPassword());

         ps.setInt(, id);

         ps.execute();

     }

     @Override

     public void delete(Connection conn, User user) throws SQLException {

         PreparedStatement ps = conn.prepareStatement("delete from uesr where id = ?");

         ps.setInt(, user.getId());

         ps.execute();

     }

 }

 package com.test.testclass;

 import java.sql.Connection;

 import java.sql.SQLException;

 import com.test.dao.UserDao;

 import com.test.dao.impl.UserDaoImpl;

 import com.test.entity.User;

 import com.test.util.ConnectionFactory;

 public class UserDaoTest {

     public static void main(String[] args) {

         Connection conn = null;

         try {

             conn = ConnectionFactory.getInstance().makeConnection();

             conn.setAutoCommit(false);

             UserDao userDao = new UserDaoImpl();

             User tom = new User();

             tom.setName("tom");

             tom.setPassword("");

             userDao.save(conn, tom);

             conn.commit();

         } catch (SQLException e) {

             try{

                 conn.rollback();

             }catch(Exception e2){

                 e2.printStackTrace();

             }

             e.printStackTrace();

         }

     }

 }