java 连接数据库mysql

以你之姓@ 2022-06-08 02:20 88阅读 0赞

连接数据库  
@class: DbConnect

public class DbConnect \{  
public static Connection getconn()  
\{  
Connection conn = null;

String user   = "root";//用户名
        String passwd = "12345678";//密码
       String url = "jdbc:mysql:localhost:3306/数据库名字";
    
    
        //已加载完驱动
        try
        {
            Class.forName("com.mysql.jdbc.Driver");
            conn = DriverManager.getConnection(url,user,passwd);
        }catch (SQLException e)
        {
            e.printStackTrace();
        }
        catch (ClassNotFoundException e)
        {
            e.printStackTrace();
        }
        return conn;
    }

## \} ##

关闭数据库  
@DbClose

public class DbClose \{

/**
     * 关闭 添加功能 资源
     * @param pstmt,rs,conn
     */
    public static void addClose(PreparedStatement pstmt, Connection conn)
    {
            /*
             * 多个 try-catch 出发点：安全
             */
        try
        {
            if (pstmt != null)
            {
                pstmt.close();
            }
        } catch (SQLException e1)
        {
            e1.printStackTrace();
        }
        try
        {
            if (conn != null)
            {
                conn.close();
            }
        } catch (SQLException e)
        {
            e.printStackTrace();
        }
    }
    
    /**
     * 关闭资源
     * @param pstmt,rs,conn
     */
    public static void queryClose(PreparedStatement pstmt, ResultSet rs, Connection conn)
    {
        try
        {
            if (pstmt != null)
            {
                pstmt.close();
            }
        } catch (SQLException e1)
        {
            e1.printStackTrace();
        }
        try
        {
            if (rs != null )
            {
                rs.close();
            }
        } catch (SQLException e1)
        {
            e1.printStackTrace();
        }
        try
        {
            if (conn != null)
            {
                conn.close();
            }
        } catch (SQLException e)
        {
            e.printStackTrace();
        }
    }

## \} ##