JDBC编程之优化

1、创建 dbconfig.properties

driver=com.mysql.jdbc.Driver
dburl=jdbc\:mysql\://localhost\:3306/mytest
user=root
password=

2、创建 ConnectionFactory.java

 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;
     }
 }

3、抽象类 IdEntity.java

 package com.test.entity;

 public abstract class IdEntity {

     protected int id;
     public int getId(){
         return id;
     }
     public void setId(int id){
         this.id = id;
     }
 }

4、User.java 继承抽象类IdEntity.java

 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
                 + "]";
     }

 }

5、Address.java 继承抽象类IdEntity.java

 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 + "]";
     }

 }

6、UserDao.java 定义接口

 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;

 }

7、实现UserDao接口，UserDaoImpl.java

 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();
     }

 }

8、测试类 UserDaoTest.java

 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();
         }

     }
 }