WEB（JSP）下的JDBC操作

package com.zss.www;

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

import com.mysql.jdbc.Connection;
import com.mysql.jdbc.PreparedStatement;

public class DBconn {


private Connection conn=null;
private PreparedStatement stmt=null;
private ResultSet rs=null;

public DBconn(){


try {
String driver="com.mysql.jdbc.Driver";
String url="jdbc:mysql://localhost:3306/school";
String user="root";
String password="711109";
Class.forName(driver);
conn = (Connection) DriverManager.getConnection(url,user,password);
System.out.println("-------连接成功------");
} catch(ClassNotFoundException classnotfoundexception) {
classnotfoundexception.printStackTrace();
System.err.println("db: " + classnotfoundexception.getMessage());
} catch(SQLException sqlexception) {
System.err.println("db.getconn(): " + sqlexception.getMessage());
}







}


public void DBConn(String driver,String url,String user,String password){

try {
//driver="com.mysql.jdbc.Driver";
//url="jdbc:mysql://localhost:3306/school";
//user="root";
//password="711109";
Class.forName(driver);
conn = (Connection) DriverManager.getConnection(url,user,password);
System.out.println("-------连接成功------");
} catch(ClassNotFoundException classnotfoundexception) {
classnotfoundexception.printStackTrace();
System.err.println("db: " + classnotfoundexception.getMessage());
} catch(SQLException sqlexception) {
System.err.println("db.getconn(): " + sqlexception.getMessage());
}

}

public void doInsert(String sql) {
try {
stmt = (PreparedStatement)conn.prepareStatement(sql);
int i = stmt.executeUpdate(sql);
} catch(SQLException sqlexception) {
System.err.println("db.executeInset:" + sqlexception.getMessage());
}finally{

}
}

public void doDelete(String sql) {
try {
stmt = (PreparedStatement)conn.prepareStatement(sql);
int i = stmt.executeUpdate(sql);
} catch(SQLException sqlexception) {
System.err.println("db.executeDelete:" + sqlexception.getMessage());
}
}

public void doUpdate(String sql) {
try {
stmt = (PreparedStatement)conn.prepareStatement(sql);
int i = stmt.executeUpdate(sql);
} catch(SQLException sqlexception) {
System.err.println("db.executeUpdate:" + sqlexception.getMessage());
}
}

public ResultSet doSelect(String sql) {
try {
stmt = (PreparedStatement)conn.prepareStatement(sql);
rs = stmt.executeQuery(sql);
System.out.println("取得结果集");
} catch(SQLException sqlexception) {
System.err.println("db.executeQuery: " + sqlexception.getMessage());
}
return rs;
}

public void close(ResultSet rs) throws SQLException, Exception {

if (rs != null) {
rs.close();
rs = null;
}

if (stmt != null) {
stmt.close();
stmt = null;
}

if (conn != null) {
conn.close();
conn = null;
}
}

public void close() throws SQLException, Exception {
if (stmt != null) {
stmt.close();
stmt = null;
}

if (conn != null) {
conn.close();
conn = null;
}
}

public static void main(String []args) throws Exception {
DBconn db=new DBconn();
ResultSet rs=db.doSelect("select * from dbuser where userNAME='chenjirong'");
try {
while(rs.next()) {
System.out.println(rs.getString(1));
System.out.println(rs.getString(2));
System.out.println(rs.getString(3));
}
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}

rs.close();
db.close();
}
}