利用servlet访问MSSQL数据库

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除了可以利用javabean访问数据库外，还可以利用servlet访问数据库。觉得servlet更方便一些。贴一个例子，方便以后参考。

本例子时根据用户选择，是删除表中内容还是显示表中内容。

servlet代码：

import java.io.IOException;import java.io.PrintWriter;import java.sql.*;import javax.servlet.ServletException;import javax.servlet.http.HttpServlet;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse;public class DBServlet extends HttpServlet {private static final long serialVersionUID = 1L; private Connection conn; /** * @see HttpServlet#HttpServlet() */ public DBServlet() { super(); // TODO Auto-generated constructor stub }/** * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response) */protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {// 设置response和request的编码方式，防止中文乱码request.setCharacterEncoding("GBK");response.setContentType("text/html;charset=GBK");PrintWriter print=response.getWriter();String command=request.getParameter("submit");if(command.equals("delete")){deleterow();print.println("顺利删除");}else if(command.equals("show")){ResultSet rs=getResult();try {if(rs!=null){while(rs.next()){print.println(rs.getString("username"));}rs.close();conn.close();}else{print.println("ResultSet为空");}} catch (SQLException e) {// TODO Auto-generated catch blocke.printStackTrace();}}}//建立连接protected void addConnection(){ String url1="com.microsoft.jdbc.sqlserver.SQLServerDriver"; String url2="jdbc:microsoft:sqlserver://localhost:1433;DatabaseName=book"; String username="sa"; String passwrd="***"; try { Class.forName(url1); conn=DriverManager.getConnection(url2,username,passwrd); } catch(Exception ex) { }}//删除表中数据protected void deleterow(){addConnection();try{String sql="use book;delete from user1";Statement stm=conn.createStatement();stm.execute(sql);stm.close();conn.close();}catch(Exception ex){}}//查询表中数据protected ResultSet getResult(){addConnection();try{String sql1="use book;select * from user1";Statement stm=conn.createStatement();ResultSet rs=stm.executeQuery(sql1);return rs;}catch(Exception ex){}return null;}/** * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response) */protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {//做与doGet一样的事情this.doGet(request,response);}}

JSP代码，如下，用了servlet之后，显得非常简单。

<%@ page language="java" contentType="text/html; charset=GBK" pageEncoding="GBK"%><!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"><html><head><meta http-equiv="Content-Type" content="text/html; charset=GBK"><title>Insert title here</title></head><body><form method="post" action="DBServlet"><table><tr><td><input name="submit" type="submit" value="delete"/></td><td><input name="submit" type="submit" value="show"/></td></tr></table></form></body></html>