jdbc书写模板（复制粘贴）

深藏阁楼爱情的钟 2024-04-01 15:49 58阅读 0赞

#### jdbc模板（复制粘贴） ####

*  1、普通版
 *   *  1.1、普通查询
     *  1.2、普通插入
 *  2、安全插入
 *  3、将常用对象封装到DBUtil中
 *  4、使用线程池
 *  5、Spring整合jdbc
 *   *  1、第一版本
     *  2、第二版本
     *  3、第三版本-事务控制

## 1、普通版 ##

### 1.1、普通查询 ###

public class MyTest {
       
        	
        public static void main(String[] args) {
       
        
            Connection conn = null;
            PreparedStatement ps = null;
            ResultSet rs = null;
            try{
       
        
                //1.加载驱动
                Class.forName("com.mysql.jdbc.Driver");
    
               //2.获取连接
    conn=
             DriverManager.getConnection("jdbc:mysql://localhost:3306/test","root","123456"); 
                //3.获取数据库操作对象
                String sql = "select * from user_table";
                ps = conn.prepareStatement(sql);
                //4.执行sql
                rs = ps.executeQuery();
                //5.处理结果集
                while(rs.next()){
       
        
                    String a = rs.getString(1);
                    String b = rs.getString(2);
                    String c = rs.getString(3);
                    System.out.println(a+","+b+","+c);
                }
            }catch(Exception e){
       
        
                e.printStackTrace();
            }finally {
       
        
                //6.关闭资源
    --------------------------------------------------------------------
    try {
       
        
        if (conn != null) {
       
        
            conn.close();
        }
    } catch (Exception e) {
       
        
        e.printStackTrace();
    }
    
    try {
       
        
        if (ps != null) {
       
        
            ps.close();
        }
    } catch (Exception e) {
       
        
        e.printStackTrace();
    }
    try {
       
        
        if (rs != null) {
       
        
            rs.close();
        }
    } catch (Exception e) {
       
        
        e.printStackTrace();
    }
    --------------------------------------------
              
     }
    }

### 1.2、普通插入 ###

import java.sql.Connection;
    import java.sql.DriverManager;
    import java.sql.PreparedStatement;
    
    public class Exer2 {
       
        
        public static void main(String[] args) {
       
        
            Connection conn = null;
            PreparedStatement ps = null;
            try{
       
        
                //1.加载驱动
                Class.forName("com.mysql.jdbc.Driver");
                //2.获取连接
                conn = DriverManager.getConnection("jdbc:mysql://localhost:3306/mydb1","root","root");
                //3.获取数据库操作对象
                String sql = "insert into ccc values(9,'a',9)";
                ps = conn.prepareStatement(sql);
                //4.执行sql
                int count = ps.executeUpdate();
            }catch (Exception e){
       
        
                e.printStackTrace();
            }finally {
       
        
                try {
       
        
                    if(conn != null){
       
        
                        conn.close();
                    }
                }catch (Exception e){
       
        
                    e.printStackTrace();
                }
                try {
       
        
                    if(ps != null){
       
        
                        ps.close();
                    }
                }catch (Exception e){
       
        
                    e.printStackTrace();
                }
            }
        }
    }

## 2、安全插入 ##

import java.sql.Connection;
    import java.sql.DriverManager;
    import java.sql.PreparedStatement;
    
    public class Exer3 {
       
        
        public static void main(String[] args) {
       
        
            Connection conn = null;
            PreparedStatement ps = null;
            try{
       
        
                //1.加载驱动
                Class.forName("com.mysql.jdbc.Driver");
                //2.获取连接
                conn = DriverManager.getConnection("jdbc:mysql://localhost:3306/mydb1","root","root");
                //3.获取数据库操作对象
                String sql = "insert into ccc values(?,?,?)";
                ps = conn.prepareStatement(sql);
                ps.setString(1,"8");
                ps.setString(2,"v");
                ps.setString(3,"8");
                //4.执行sql
                int count = ps.executeUpdate();
            }catch (Exception e){
       
        
                e.printStackTrace();
            }finally {
       
        
                try {
       
        
                    if(conn != null){
       
        
                        conn.close();
                    }
                }catch (Exception e){
       
        
                    e.printStackTrace();
                }
                try {
       
        
                    if(ps != null){
       
        
                        ps.close();
                    }
                }catch (Exception e){
       
        
                    e.printStackTrace();
                }
            }
        }
    }

## 3、将常用对象封装到DBUtil中 ##

> DBUtil类

public class DBUtil {
       
        
        private DBUtil(){
       
        }
        static {
       
        
            try {
       
        
                Class.forName("con.mysql.jdbc.Driver");
            } catch (ClassNotFoundException e) {
       
        
                e.printStackTrace();
            }
        }
        public static Connection getConnection() throws SQLException {
       
        
    
            return DriverManager.getConnection("jdbc:mysql://localhost:3306/test","root","123456");
    
        }
    
        public static void close(Connection connection, Statement ps,ResultSet rs){
       
        
            try{
       
        
                if(ps!=null){
       
        
                    ps.close();
                }
            }catch(Exception e){
       
        
                e.printStackTrace();
            }
            try{
       
        
                if(connection!=null){
       
        
                    connection.close();
                }
            }catch (Exception e){
       
        
                e.printStackTrace();
            }
            try{
       
        
                if(rs!=null){
       
        
                    rs.close();
                }
            }catch (Exception e){
       
        
                e.printStackTrace();
            }
        }
    }

> 实现类

public class Thried {
       
        
        public static void main(String[] args) {
       
        
            Connection conn = null;
            ResultSet rs = null;
            PreparedStatement ps = null;
            try {
       
        
                //1.加载驱动
                //2.获取连接
                conn