package com.melin.bbs; 

  import java.sql.Connection;  import java.sql.DriverManager;  import java.sql.ResultSet;  import java.sql.SQLException;  import java.sql.Statement; 

public class DB {

//建立连接

    public static Connection getConn(){ 

        Connection conn=null;          try {              Class.forName("com.mysql.jdbc.Driver");          } catch (ClassNotFoundException e) {             e.printStackTrace(); 

        } 

        try {         conn=DriverManager.getConnection("jdbc:mysql://localhost:3306/bbs","root","root");          } catch (SQLException e) {              e.printStackTrace();          }          return conn;      }      

//SQL语句发送到数据库

     public static Statement getStmt(Connection conn){ 

        Statement stmt=null;          try {              stmt=conn.createStatement();          } catch (SQLException e) {             e.printStackTrace();          }          return stmt;      }

//返回结果集

    public static ResultSet getRs(Statement stmt,String sql){          ResultSet rs=null;          try {              rs=stmt.executeQuery(sql);          } catch (SQLException e) {               e.printStackTrace();          }          return rs;      }      

//关闭连接

    public static void close(Connection conn){ 

        if(conn!=null){              try {                  conn.close();              } catch (SQLException e) {                  // TODO Auto-generated catch block                  e.printStackTrace();              }              conn=null;          }      } 

    public static void close(ResultSet rs){          if(rs!=null){              try {                  rs.close();              } catch (SQLException e) {                  e.printStackTrace();              }              rs=null;          }      }            public static void close(Statement stmt){          if(stmt!=null){              try {                  stmt.close();              } catch (SQLException e) {                  // TODO Auto-generated catch block                  e.printStackTrace();              }              stmt=null;          }      }    }