java模拟登陆正方教务管理系统

学了java后想设计一个在线提交活动中心使用申请的web网站，但问题是学生身份的验证。开始时是设想每年爬取一次全校学生信息，但速度太慢了，而且学号的规律也不清楚。然后想到借用教务管理系统自带的验证功能，这样不用更新数据库，但是每到抢课或查成绩的时候教务管理系统总会比较卡，但其他大部分时间都没问题，所以就采用模拟登陆教务管理系统的方式来验证登录用户的身份。

登录教务管理系统需要输入学号、密码、验证码以及用户身份，因为是验证学生身份的，所以身份这一项固定死为学生。经过实验发现验证码是由另外的js生成验证的，而且默认0为正确，所以验证码可以不用输入。在firefox上用adblock屏蔽了验证码的js，然后直接输学号和密码就能登录了。

通过调试功能查看发送的数据。第一个数据的值在网页中是固定的，但不知道是否会换，所以用java的正则获取这个值，第二个是学号，第三个是密码，第四个是验证码，第五个是登录身份，后两个不知道是什么。

登录页面是default2.aspx，登录成功后的页面是xs_main.aspx，只要检测返回地址是否匹配就能验证登录是否成功了。

实际测试可以验证成功。

相关代码：

package www.wamgk.com;

import java.io.BufferedReader;
import java.io.DataOutputStream;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.net.HttpURLConnection;
import java.net.URL;
import java.net.URLConnection;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;

import java.sql.Connection;  
import java.sql.ResultSet;  
import java.sql.SQLException;  
import java.sql.Statement;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

import net.sf.json.JSONArray;
import net.sf.json.JSONObject; 

/**
 * Servlet implementation class ckecklogin
 */
@WebServlet("/acms/ckecklogin")
public class ckecklogin extends HttpServlet {
	private static final long serialVersionUID = 1L;
	private String VIEWSTATE;
	String targeturl="http://jwgl.hunnu.edu.cn";
	   
	/**
	 * @see HttpServlet#HttpServlet()
	 */
	public ckecklogin() {
		super();
		// TODO Auto-generated constructor stub
		PrintWriter out = null;
		BufferedReader in = null;
		try {
			URL realUrl = new URL(targeturl);
			// 打开和URL之间的连接
			URLConnection conn = realUrl.openConnection();
			// 设置通用的请求属性
			conn.setRequestProperty("accept", "*/*");
			conn.setRequestProperty("connection", "Keep-Alive");
			conn.setRequestProperty("user-agent","Mozilla/5.0 (Windows NT 10.0; WOW64; rv:43.0) Gecko/20100101 Firefox/43.0");
			// 发送POST请求必须设置如下两行
			conn.setDoOutput(true);
			conn.setDoInput(true);
			// 获取URLConnection对象对应的输出流
			out = new PrintWriter(conn.getOutputStream());
			// 发送请求参数
			//out.print(param);
			
			// flush输出流的缓冲
			out.flush();
			// 定义BufferedReader输入流来读取URL的响应
			in = new BufferedReader(new InputStreamReader(conn.getInputStream()));
			Pattern pattern = Pattern.compile("name=\"__VIEWSTATE\" value=\"([a-zA-Z0-9]*)\"");
			//Matcher matcher;
			String line;
			for(;(line = in.readLine()) != null;) {
				//System.out.printf("%3d-->",i);
				//System.out.println(line);
				Matcher matcher = pattern.matcher(line);
				//System.out.println(matcher.matches());//匹配结果
				if(matcher.find()){//输出匹配成功的字符串
					//System.out.println(" - "+matcher.group(0));
					//System.out.println("VIEWSTATE - "+matcher.group(1));
					VIEWSTATE=matcher.group(1);
					break;
				}
			}
			System.out.println("VIEWSTATE :" + VIEWSTATE);
		} catch (Exception e) {
			e.printStackTrace();
		}finally{
			try{
				if(out!=null){
					out.close();
				}
				if(in!=null){
					in.close();
				}
			}
			catch(IOException ex){
				ex.printStackTrace();
			}
		}
	}
	
	protected int checkXhAnsPwd(String xh,String pwd){
		String location;
		
		try {
			URL realUrl1 = new URL(targeturl);
			
			HttpURLConnection connurl = (HttpURLConnection)realUrl1.openConnection();	
			connurl.setRequestMethod("GET");	
			// 必须设置false，否则会自动redirect到Location的地址	
			connurl.setInstanceFollowRedirects(false);	
	
			connurl.addRequestProperty("Accept-Charset", "UTF-8;");	
			connurl.addRequestProperty("User-Agent","Mozilla/5.0 (Windows NT 10.0; WOW64; rv:43.0) Gecko/20100101 Firefox/43.0");	
			//connurl.addRequestProperty("Referer", "http://zuidaima.com/");	
			connurl.connect();	
			location = targeturl+connurl.getHeaderField("Location");	
			System.out.println(location);
			
			//建立连接
			URL url=new URL(location);
			HttpURLConnection httpConn=(HttpURLConnection)url.openConnection();
			//设置参数
			httpConn.setDoOutput(true);	 //需要输出
			httpConn.setDoInput(true);	 //需要输入
			httpConn.setUseCaches(false);	//不允许缓存
			httpConn.setRequestMethod("POST");	 //设置POST方式连接
			//设置请求属性
			httpConn.setRequestProperty("Content-Type", "application/x-www-form-urlencoded");
			httpConn.setRequestProperty("Connection", "Keep-Alive");// 维持长连接
			httpConn.setRequestProperty("Charset", "UTF-8");
			//连接,也可以不用明文connect，使用下面的httpConn.getOutputStream()会自动connect
			httpConn.connect();
				
			//建立输入流，向指向的URL传入参数
			DataOutputStream dos=new DataOutputStream(httpConn.getOutputStream());
			dos.writeBytes("__VIEWSTATE="+VIEWSTATE+"&TextBox1="+xh+"&TextBox2="+pwd+"&RadioButtonList1=%D1%A7%C9%FA&Button1=a");
			dos.flush();
			dos.close();
			//获得响应状态
			//int resultCode=httpConn.getResponseCode();
			//System.out.println(resultCode);
			if(HttpURLConnection.HTTP_OK==httpConn.getResponseCode()){
				BufferedReader responseReader=new BufferedReader(new InputStreamReader(httpConn.getInputStream()));
				responseReader.close();
				//登录成功返回包含xs_main.aspx字符串
				location=httpConn.getURL().toString();
				System.out.println(location);
				if(location.indexOf("xs_main.aspx")!=-1){
					//未找到则登录失败
					return 0;
				}
			} 
			return 1;
			
		} catch (Exception e) {
			e.printStackTrace();
		}
		return -1;
	}
	
	protected int checkuserinfo(String name,String pwd){
		Connection conn = null;  
		Statement stmt = null;  
		ResultSet rs = null;
		//System.out.println("check");
		try {  
			
			if(checkXhAnsPwd(name,pwd)==0){
				//学生
				return 0;
			}
			else{
				//管理员
				conn = C3P0cnn.getConnection();
				stmt = conn.createStatement(); 
				//查询管理员表
				ResultSet rs2 = stmt.executeQuery("select pwd,authority from t_admin where name='"+name+"'");
				//System.out.println("is admin");
				while (rs2.next()) {
					if(pwd.equals(rs2.getString("pwd"))==true){
						//System.out.println("is admin authority="+rs2.getString("authority"));
						return Integer.parseInt(rs2.getString("authority"));
					}
				}
				//System.out.println("not admin");
			}
		} catch (SQLException e) {  
			e.printStackTrace();  
		} finally {  
			try {  
				if (rs != null)  
					rs.close();  
				if (stmt != null)  
					stmt.close();  
				if (conn != null)  
					conn.close();
			} catch (Exception e) {  
				e.printStackTrace();  
			}  
		}
		return -1;  
	}

	/**
	 * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
	 */
	protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		// TODO Auto-generated method stub
		response.setCharacterEncoding("UTF-8");
		String name=request.getParameter("name");
		String pwd=request.getParameter("pwd");
		System.out.println("name="+name+"-pwd="+"*");
		
		HttpSession session = request.getSession();
		session.setAttribute("name",name);//在服务器端存储"键-值对"
		
		PrintWriter out =  response.getWriter();
		JSONObject json = new JSONObject();
		int tmp=checkuserinfo(name,pwd);
		switch(tmp){
		case -1:
			json.put("code","0");
			json.put("msg","用户名或密码错误");
			//session.setAttribute("msg","用户名或密码错误");
			break;
		default:
			json.put("code","1");
			json.put("msg","登陆成功");
			session.setAttribute("authority",tmp);
		}
		
		out.write(json.toString());
	}

	/**
	 * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
	 */
	protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		// TODO Auto-generated method stub
		doGet(request, response);
	}

}