过滤器的应用之自动登录--filter(三)

实现用户自动登陆的过滤器

原理：在用户登陆成功后，以cookis形式发送用户名、密码给客户端

编写一个过滤器，filter方法中检查cookie中是否带有用户名、密码信息，如果存在则调用业务层登陆方法，登陆成功后则向session中存入user对象（即用户登陆标记），以实现程序完成自动登陆

package com.jjyy.web;

import java.io.IOException;
import java.sql.SQLException;

import javax.servlet.ServletException;
import javax.servlet.http.Cookie;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.apache.commons.dbutils.QueryRunner;
import org.apache.commons.dbutils.handlers.BeanHandler;

import com.jjyy.domain.User;
import com.jjyy.util.DaoUtils;
import com.jjyy.util.MD5Utils;

public class LoginServlet extends HttpServlet {

	public void doGet(HttpServletRequest request, HttpServletResponse response)
			throws ServletException, IOException {
		//1.获取用户名密码
		String name = request.getParameter("name");
		String password  = MD5Utils.md5(request.getParameter("password"));
		//2.校验用户名密码
		String sql = "select * from user where name = ? and password = ? ";
		User user = null;
		try {
			QueryRunner runner = new QueryRunner(DaoUtils.getSource());
			user = runner.query(sql, new BeanHandler<User>(User.class),name,password);
		} catch (SQLException e) {
			e.printStackTrace();
		}
		if(user == null){
			response.getWriter().write("用户名密码不正确");
			return;
		}else{
				//3.登录用户
				request.getSession().setAttribute("user", user);
			
				// 如果用户勾选过30天内自动登陆,发送自动登陆cookie
				if("true".equals(request.getParameter("autologin"))){
					Cookie autologinC = new Cookie("autologin",user.getName()+":"+user.getPassword());
					autologinC.setPath(request.getContextPath());
					autologinC.setMaxAge(3600*24*30);
					response.addCookie(autologinC);
				}
				
				
				//4.重定向到主页
				response.sendRedirect(request.getContextPath()+"/index.jsp");
		}
	}

	public void doPost(HttpServletRequest request, HttpServletResponse response)
			throws ServletException, IOException {
		doGet(request, response);
	}

}

package com.jjyy.web;

import java.io.IOException;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

public class LogoutServlet extends HttpServlet {

	public void doGet(HttpServletRequest request, HttpServletResponse response)
			throws ServletException, IOException {
		if(request.getSession(false)!=null){
			request.getSession().invalidate();
		}
		response.sendRedirect(request.getContextPath()+"/index.jsp");
	}

	public void doPost(HttpServletRequest request, HttpServletResponse response)
			throws ServletException, IOException {
		doGet(request, response);
	}

}

package com.jjyy.domain;

import java.io.Serializable;

public class User implements Serializable {
	private int id;
	private String name;
	private String password;
	private String role;
	public int getId() {
		return id;
	}
	public void setId(int id) {
		this.id = id;
	}
	public String getName() {
		return name;
	}
	public void setName(String name) {
		this.name = name;
	}
	public String getPassword() {
		return password;
	}
	public void setPassword(String password) {
		this.password = password;
	}
	public String getRole() {
		return role;
	}
	public void setRole(String role) {
		this.role = role;
	}
}

package com.jjyy.filter;

import java.io.IOException;
import java.sql.SQLException;

import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.http.Cookie;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.xml.registry.infomodel.User;

import org.apache.commons.dbutils.QueryRunner;
import org.apache.commons.dbutils.handlers.BeanHandler;

import com.jjyy.util.DaoUtils;
/**
 * autoLoginFilter
 * @author JiangYu
 *
 */
public class AutoLoginFilter implements Filter {

	public void destroy() {

	}

	public void doFilter(ServletRequest request, ServletResponse response,
			FilterChain chain) throws IOException, ServletException {
		HttpServletRequest req = (HttpServletRequest) request;
		HttpServletResponse resp = (HttpServletResponse) response;
		//1.只有未登录的用户才能自动登陆
		if(req.getSession(false)==null || req.getSession().getAttribute("user")==null){
			//2.只有带了自动登陆cookie的用户才能自动登陆
			Cookie [] cs = req.getCookies();
			Cookie findC = null;
			if(cs!=null){
				for(Cookie c : cs){
					if("autologin".equals(c.getName())){
						findC = c;
						break;
					}
				}
			}
			
			if(findC!=null){
				//3.自动登录Cookie中保存的用户名密码都需要是正确的才能自动登陆
				String name = findC.getValue().split(":")[0];
				String password= findC.getValue().split(":")[1];
				String sql = "select * from user where name = ? and password = ? ";
				User user = null;
				try {
					QueryRunner runner = new QueryRunner(DaoUtils.getSource());
					user = runner.query(sql, new BeanHandler<User>(User.class),name,password);
				} catch (SQLException e) {
					e.printStackTrace();
				}
				
				if(user!=null){
					req.getSession().setAttribute("user", user);
				}
			}
		}
		//无论是否自动登陆,都放行资源
		chain.doFilter(request, response);
	}

	public void init(FilterConfig arg0) throws ServletException {

	}

}

package com.jjyy.filter;

import java.io.IOException;
import java.io.UnsupportedEncodingException;
import java.util.Map;

import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletRequestWrapper;

public class EncodeFilter implements Filter {
	private FilterConfig config = null;
	private String encode = null;
	public void destroy() {

	}

	public void doFilter(ServletRequest request, ServletResponse response,
			FilterChain chain) throws IOException, ServletException {
		//响应的乱码处理
		response.setContentType("text/html;charset=utf-8");
		//装饰
		chain.doFilter(new MyHttpServletRequest((HttpServletRequest)request), response);
	}

	public void init(FilterConfig filterConfig) throws ServletException {
		this.config = filterConfig;
		this.encode = config.getInitParameter("encode")==null?"utf-8":config.getInitParameter("encode");
	}
	//请求乱码的处理
	class MyHttpServletRequest extends HttpServletRequestWrapper{
		private HttpServletRequest request = null;
		boolean isNotEncode = true;
		public MyHttpServletRequest(HttpServletRequest request) {
			super(request);
			this.request = request;
		}
		
		@Override
		public Map getParameterMap() {
			try {
				if(request.getMethod().equalsIgnoreCase("POST")){
					request.setCharacterEncoding(encode);
					return request.getParameterMap();
				}else if(request.getMethod().equalsIgnoreCase("GET")){
					//request.getParameterMap()第一次会解决，然后缓存起来
					//request.getParameterMap()第二次直接从缓存中的map
					Map<String,String[]> map = request.getParameterMap();
					if(isNotEncode){
						for(Map.Entry<String, String[]> entry:map.entrySet()){
							String [] vs = entry.getValue();
							for(int i=0;i<vs.length;i++){
								vs[i]= new String(vs[i].getBytes("iso8859-1"),encode);
							}
						}
						isNotEncode = false;
					}
					return map;
				}else{
					return request.getParameterMap();
				}
			} catch (UnsupportedEncodingException e) {
				e.printStackTrace();
			}
			return super.getParameterMap();
		}
		
		@Override
		public String getParameter(String name) {
			
			return getParameterValues(name)==null?null:getParameterValues(name)[0];
		}
		@Override
		public String[] getParameterValues(String name) {
			return (String[])getParameterMap().get(name);
		}
	}
}

package com.jjyy.util;

import java.math.BigInteger;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;

public class MD5Utils {
	public static String md5(String plainText) {
		byte[] secretBytes = null;
		try {
			secretBytes = MessageDigest.getInstance("md5").digest(plainText.getBytes());
		} catch (NoSuchAlgorithmException e) {
			throw new RuntimeException("没有md5这个算法！");
		}
		String md5code = new BigInteger(1, secretBytes).toString(16);
		for (int i = 0; i < 32 - md5code.length(); i++) {
			md5code = "0" + md5code;
		}
		return md5code;
	}
}

package com.jjyy.util;


import java.sql.Connection;
import java.sql.SQLException;

import javax.sql.DataSource;

import com.mchange.v2.c3p0.ComboPooledDataSource;

public class DaoUtils {
	private static DataSource source = new ComboPooledDataSource();
	private DaoUtils() {
	}
	
	public static DataSource getSource(){
		return source;
	}
	
	public static Connection getConn(){
		try {
			return source.getConnection();
		} catch (SQLException e) {
			e.printStackTrace();
			throw new RuntimeException(e);
		}
	}
}