servlet学习笔记之七(连接mysql)

set names gbk 解决mysql乱码

数据库中选ＵＴＦ８防止乱码

注意考贝jdbc的驱动到webappliction的lib目录下

 

import java.sql.*;

public class DB {
    public static Connection getConn() {
        Connection conn = null;
        try {
            Class.forName("com.mysql.jdbc.Driver");
            conn = DriverManager.getConnection("jdbc:mysql://localhost/bbs?user=root&password=root");
        } catch (ClassNotFoundException e) {
            e.printStackTrace();
        } catch (SQLException e) {
            e.printStackTrace();
        }
        
        return conn;
    }
    
    public static Statement getStatement(Connection conn) {
        Statement stmt = null; 
        try {
            if(conn != null) {
                stmt = conn.createStatement();
            }
        } catch (SQLException e) {
            e.printStackTrace();
        }
        return stmt;
    }
    
    public static ResultSet getResultSet(Statement stmt, String sql) {
        ResultSet rs = null;
        try {
            if(stmt != null) {
                rs = stmt.executeQuery(sql);
            }
        } catch (SQLException e) {
            e.printStackTrace();
        }
        return rs;
    }
    
    public static void closeConn(Connection conn) {
        try {
            if(conn != null) {
                conn.close();
                conn = null;
            }
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }
    
    public static void closeStmt(Statement stmt) {
        try {
            if(stmt != null) {
                stmt.close();
                stmt = null;
            }
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }
    
    public static void closeRs(ResultSet rs) {
        try {
            if(rs != null) {
                rs.close();
                rs = null;
            }
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }
}