Druid C3P 0 연결 풀 사용 및 DBUtils 사용 및 사무

01 Druid 연결 풀

1.         
@Test
//          :
public void demo1(){
    Connection conn = null;
    PreparedStatement pstmt = null;
    ResultSet rs = null;
    DruidDataSource dataSource = new DruidDataSource();
    dataSource.setDriverClassName("com.mysql.jdbc.Driver");
    dataSource.setUrl("jdbc:mysql:///day04");
    dataSource.setUsername("root");
    dataSource.setPassword("123");
    try{
        //     :
        conn = dataSource.getConnection();
        //   SQL：
        String sql = "select * from account";
        pstmt = conn.prepareStatement(sql);
        //   sql:
        rs = pstmt.executeQuery();
        while(rs.next()){
            System.out.println(rs.getInt("id")+"   "+rs.getString("name")+"   "+rs.getDouble("money"));
        }
    }catch(Exception e){
        e.printStackTrace();
    }finally{
        JDBCUtils.release(rs, pstmt, conn);
    }
    
}
2.       .properties     Properties      
@Test 
public void demo2(){
    Connection conn = null;
    PreparedStatement pstmt = null;
    ResultSet rs = null;
    
    try{
        Properties properties = new Properties();
        properties.load(new FileInputStream("src/druid.properties"));
        DataSource dataSource = DruidDataSourceFactory.createDataSource(properties);
        //     :
        conn = dataSource.getConnection();
        //   SQL：
        String sql = "select * from account";
        pstmt = conn.prepareStatement(sql);
        //   sql:
        rs = pstmt.executeQuery();
        while(rs.next()){
            System.out.println(rs.getInt("id")+"   "+rs.getString("name")+"   "+rs.getDouble("money"));
        }
    }catch(Exception e){
        e.printStackTrace();
    }finally{
        JDBCUtils.release(rs, pstmt, conn);
    }
}

02 C3P 0 연결 풀

1.          
@Test
//          :
public void demo1(){
    Connection conn = null;
    PreparedStatement pstmt = null;
    ResultSet rs = null;
    
    try{
        //    :
        ComboPooledDataSource dataSource = new ComboPooledDataSource();
        //       :
        dataSource.setDriverClass("com.mysql.jdbc.Driver");
        dataSource.setJdbcUrl("jdbc:mysql:///day04");
        dataSource.setUser("root");
        dataSource.setPassword("123");
        //     :
        conn = dataSource.getConnection();
        //   SQL：
        String sql = "select * from account";
        pstmt = conn.prepareStatement(sql);
        //   sql:
        rs = pstmt.executeQuery();
        while(rs.next()){
            System.out.println(rs.getInt("id")+"   "+rs.getString("name")+"   "+rs.getDouble("money"));
        }
    }catch(Exception e){
        e.printStackTrace();
    }finally{
        JDBCUtils.release(rs, pstmt, conn);
    }
    
}

2.        
@Test
//        
public void demo2(){
    Connection conn = null;
    PreparedStatement pstmt = null;
    ResultSet rs = null;
    
    try{
        //    :
        ComboPooledDataSource dataSource = new ComboPooledDataSource();
        //     :
        conn = dataSource.getConnection();
        //   SQL：
        String sql = "select * from account";
        pstmt = conn.prepareStatement(sql);
        //   sql:
        rs = pstmt.executeQuery();
        while(rs.next()){
            System.out.println(rs.getInt("id")+"   "+rs.getString("name")+"   "+rs.getDouble("money"));
        }
    }catch(Exception e){
        e.printStackTrace();
    }finally{
        JDBCUtils.release(rs, pstmt, conn);
    }
    
}

03 DBUtils 사용

    API：
    QueryRunner     ：     
    ResultSetHandler    ：         
    DbUtils         ：   

    @Test
     DBUils
    public void demo1() throws SQLException{
        QueryRunner queryRunner = new QueryRunner(JDBCUtils2.getDataSource());
        String sql = "insert into account values (null,?,?)";
        queryRunner.update(sql, "   ",10000);
    
    }

1.  
@Test
//     
public void demo1() throws SQLException{
    QueryRunner queryRunner = new QueryRunner(JDBCUtils2.getDataSource());
    String sql ="insert into account values (null,?,?)";
    queryRunner.update(sql, "aaa",10000);
}
2.  
@Test
//     
public void demo2() throws SQLException{
    QueryRunner queryRunner = new QueryRunner(JDBCUtils2.getDataSource());
    String sql ="update account set name=?,money=? where id =?";
    queryRunner.update(sql, "bbb",20000,4);
}
3.  
@Test
//     
public void demo3() throws SQLException{
    QueryRunner queryRunner = new QueryRunner(JDBCUtils2.getDataSource());
    String sql ="delete from account where id =?";
    queryRunner.update(sql, 4);
}
4.  
ArrayHandler：
@Test
// ArrayHandler:                
public void demo1() throws SQLException{
    QueryRunner queryRunner = new QueryRunner(JDBCUtils2.getDataSource());
    String sql  = "select * from account where id = ?";
    Object[] objs = queryRunner.query(sql, new ArrayHandler(), 1);
    System.out.println(Arrays.toString(objs));
}
ArrayListHandler：
         ，           ，                
@Test
// ArrayListHandler:            ，           ，                
public void demo2() throws SQLException{
    QueryRunner queryRunner = new QueryRunner(JDBCUtils2.getDataSource());
    String sql = "select * from account";
    List

04 JDBC 의 사무 관리

 Connection              API：
setAutoCommit(boolean flag);
commit();
rollback();
    ：
@Test
//       
public void demo1(){
    Connection conn = null;
    PreparedStatement pstmt = null;
    try{
        //     :
        conn = JDBCUtils.getConnection();

        ###！！//     :（***  ***）
        conn.setAutoCommit(false);

        //   SQL:
        String sql = "update account set money = money + ? where name = ?";
        //    SQL:
        pstmt = conn.prepareStatement(sql);
        //     ：
        //      1000 
        pstmt.setDouble(1, -1000);
        pstmt.setString(2, "  ");
        pstmt.executeUpdate(); //   
        
        int d = 1 / 0;
        
        //      1000
        pstmt.setDouble(1, 1000);
        pstmt.setString(2, "  ");
        pstmt.executeUpdate(); //   
        
        ###！！//     :（***  ***）
        conn.commit();
    }catch(Exception e){
        ###！！//     :（***  ***）
        try {
            conn.rollback();
        } catch (SQLException e1) {
            e1.printStackTrace();
        }
        e.printStackTrace();
    }finally{
        //     :
        JDBCUtils.release(pstmt, conn);
    }
}