手写JDBC - 数据库、驱动信息存储在配置文件

1. 将数据库、驱动信息存储在配置文件

configure.properties

1 url=jdbc:mysql://localhost:3306/数据库名?serverTimezone=GMT&useSSL=false
2 user=用户名，一般是root
3 password=数据库密码
4 driver=com.mysql.cj.jdbc.Driver

 

2. JDBC工具类

MyDBUtil.java

 1 import java.io.InputStream;
 2 import java.sql.*;
 3 import java.util.Properties;
 4 
 5 /**
 6  * 手写实现JDBC工具类
 7  * @author Nemo
 8  * @version 1.0
 9  * @date 2019/4/10
10  */
11 public class MyDBUtil {
12     private static String url;
13     private static Properties proterties;
14     
15     // 注册驱动
16     static {
17         proterties = new Properties;
18         
19         InputStream configureStream = MyDBUtil.class.getClassLoader.getResourceAsStream("configure.proterties");
20         try {
21             properties.load(configureStream);
22             String driver = properties.getProperty("driver");
23             class.forName(driver);
24             
25             url = properties.getProperty("url");
26         } catch (Exception e) {
27             e.printStackTrace();
28         }
29     }
30     
31     // 获取连接
32     public static Connection getConnection() throw SQLException{
33         return DriverManager.getConnection(url, properties);
34     }
35     
36     // 释放资源
37     public static void release(Statement statement, Connection connection, ResultSet resultSet) {
38         closeQuietly(statement);
39         closeQuietly(connection);
40         closeQuietly(resultSet);
41     }
42     // 重载释放资源
43     public static void release(Statement statement, Connection connection) {
44         closeQuietly(statement);
45         closeQuietly(connection);
46     }
47     
48     private static void closeQuietly(AutoCloseable closeable) {
49         if (closeable != null) {
50             try {
51                 closeable.close();
52             } catch (Exception e) {
53                 e.printStackTrace();
54             }
55         }
56     }
57 }

 

3. 以实现数据库事务为例，演示工具类的使用

TranctionTest.java

 1 import org.junit.Test;
 2 
 3 import java.sql.Connection;
 4 import java.sql.SQLException;
 5 import java.sql.Savepoint;
 6 import java.sql.Statement;
 7 
 8 /**
 9  * 以数据库事务为例进行演示
10  * @author Nemo
11  * @version 1.0
12  * @date 2019/4/13
13  */
14 public class TranctionTest {
15     @Test
16     public void traction() throws SQLException {
17         Connection conn = null;
18         Statement stm = null;
19         Savepoint savepoint = null;
20         try {
21             // 获取数据库连接
22             conn = MyDBUtil.getConnection();
23             
24             // 关闭数据库自动commit功能
25             conn.setAutoCommit(false);
26             
27             // 建立sql语句
28             stm = conn.cteateStatement();
29             
30             // zs给lisi转账100
31             String sql1 = "update user set money=money-100 where name='zs';";
32             String sql2 = "update user set money=money+100 where name='lisi';";
33             
34             // wangwu给lisi转账100
35             String sql3 = "update user set money=money-100 where name='wangwu';";
36             String sql4 = "update user set money=money+100 where name='lisi';";
37             
38             // 提交sql语句
39             stm.executeUpdate(sql1);
40             stm.executeUpdate(sql2);
41             
42             // 设置savepoint
43             savepoint = conn.setSavepoint();
44             
45             int i = 1/0;
46             
47             stm.executeUpdate(sql3);
48             stm.executeUpdate(sql4);
49             
50             conn.commit();
51         } catch (Exception e) {
52             conn.rollback(savepoint);
53             conn.commit();
54         } finally {
55             MyDBUtil.release(statement, connection);
56         }
57     }
58 }

 

posted @ 2019-04-13 16:58  NemoWang  阅读(679)  评论(0)  编辑  收藏  举报