自动登录
使用过滤器(Filter)实现用户自动登录
应用场景:现在大部分网站都支持一段时间类用户自动登陆功能,移动端APP应用几乎都需要自动登陆,试想一下如果你每天打开微信或者QQ等APP时每次都需要手动输入用户名密码然后在登录,内心早已是一万匹草泥马.所以说自动登录功能对于提高用户体验时非常重要的.
那么下面我们就来自己实现一个简单的用户自定登录案列吧!
自动登陆案列分析
开发语言:java
开发工具:Eclipse Oxygen版(2018 3月发布) 服务器: tomcat 7.0 , jdk1.8 数据库:mysql 5.5
相关工具包:
c3p0-0.9.1.2.jar(c3p0连接池jar包)commons-dbutils-1.4.jar(简化数据处理jar包,可以自己封装)jstl.jar(jstl jar包)mysql-connector-java-5.1.39-bin.jar(mysql驱动)standard.jar(jstl jar包)
1.准备数据
create database autologin;
use autologin;
create table user(
id int primary key auto_increment,
username varchar(20),
password varchar(20),
birthday date,
email varchar(60)
);
insert into user values(null,'Tom','123456','1990-10-18','[email protected]');
insert into user values(null,'Jack','123456','1921-07-01','[email protected]');
insert into user values(null,'Bob','123456','1990-02-22','[email protected]');前端页面 login.jsp
<%@page import="com.utils.CookieUtil"%> <%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%> <%@taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c" %> <!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=UTF-8"> <title>登录页面</title> </head> <body> <%--如果用户已登录,直接掉转到首页 --%> <c:if test="${not empty user }"> <jsp:forward page="/index.jsp"></jsp:forward> </c:if> <%--如果用户未登录就显示下面的页面 --%> <form action="${pagecontext.request.contextpath }/login" method="post"> 用户名<input type="text" name="username"><br> 密码<input type="password" name="pwd"><br> 自动登录<input type="checkbox" name="auto" value="on"><br> <input type="submit" value="登录"> </form> </body> </html>
index.jsp
<%@page import="com.bean.User"%>
<%@ page language="java" contentType="text/html; charset=UTF-8"
pageEncoding="UTF-8"%>
<%@taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c" %>
<!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=UTF-8">
<title>首页</title>
</head>
<body>
<%--判断是否已登录，如果已登录则显示欢迎XXX登录 注销 购物车
如果未登录，则显示 注册 登录
怎么判断是否已登录?只要登录成功，就会将user对象存放到session中，所以判断session中是否有user就可以知道是否已登录
--%>
<c:if test="${not empty user }">
<h1>欢迎你回来${user.username }!</h1>
<a href="${pageContext.request.contextPath }/logout">注销</a>
<a href="${pageContext.request.contextPath }/car.jsp">购物车</a>
</c:if>
<c:if test="${empty user }">
<a href="${pageContext.request.contextPath }/register.jsp">注册</a>
<a href="${pageContext.request.contextPath }/login.jsp">登录</a>
</c:if>
</body>
</html>car.jsp
<%@ page language="java" contentType="text/html; charset=UTF-8"
pageEncoding="UTF-8"%>
<%@taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>Insert title here</title>
</head>
<body>
<c:if test="${empty user}">
<jsp:forward page="/login.jsp"></jsp:forward>
</c:if>
<c:if test="${not empty user}">
<h1>${user.username }欢迎来到我的购物车</h1>
</c:if>
</body>
</html>register.jsp
<%@ page language="java" contentType="text/html; charset=UTF-8"
pageEncoding="UTF-8"%>
<!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=UTF-8">
<title>注册页面</title>
</head>
<body>
<h1>欢迎加入我们!</h1>
</body>
</html>服务端代码
LoginServlet.java
package com.servlet; import java.io.IOException; import java.io.printwriter; import javax.servlet.ServletContext; 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 javax.servlet.http.HttpSession; import com.bean.User; import com.service.UserService; import com.utils.CookieUtil; /** * 处理用户登录的Servlet */ public class LoginServlet extends HttpServlet { private static final long serialversionuid = 1L; protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { response.setcontenttype("text/html;charset=utf-8"); String username = request.getparameter("username"); String password = request.getParameter("pwd"); String auto = request.getParameter("auto"); HttpSession session = request.getSession(); //调用业务层方法登录 UserService service=new UserService(); User user=service.doLogin(username,password); System.out.println(user); if (user!=null) { //当用户选择自动登陆后,我们怎样才能实现用户自动登陆成功呢?首先将用户登录成功的用户名和密码存入cookie并发送到客户端 Cookie cookie = CookieUtil.createCookie("info",username+"#"+password,7*24*60*60,request.getContextPath()); //判断用户是否选择了自动登陆 if (!"on".equalsignorecase(auto)) { //如果用户没有选择自动登陆,则需要把cookie清空 cookie.setMaxAge(0); } //把cookie发送到客服端 response.addCookie(cookie); //登录成功,把user存入session中 session.setattribute("user",user); response.sendredirect(request.getContextPath()+"/index.jsp"); }else { response.sendRedirect(request.getContextPath()+"/login.jsp"); } } protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { doGet(request, response); } }
UserService.java
package com.service;
import java.sql.SQLException;
import java.util.List;
import com.bean.User;
import com.dao.UserDao;
public class UserService {
public User doLogin(String username, String password) {
UserDao dao = new UserDao();
User user=null;
try {
user = dao.doLogin(username, password);
} catch (SQLException e) {
e.printstacktrace();
}
return user;
}
}UserDao.java
package com.dao; import java.sql.SQLException; import org.apache.commons.dbutils.QueryRunner; import org.apache.commons.dbutils.handlers.BeanHandler; import com.bean.User; import com.utils.C3P0Utils; public class UserDao { public User doLogin(String username, String password) throws SQLException { QueryRunner runner = new QueryRunner(C3P0Utils.getdatasource()); String sql = "select * from user where username=? and password=?"; User user = runner.query(sql, new BeanHandler<>(User.class), username, password); return user; } }
AutoLoginFilter.java
package com.filter; import java.io.IOException; 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.HttpServletResponse; import javax.servlet.http.HttpSession; import com.bean.User; import com.service.UserService; import com.utils.CookieUtil; /** * 如果进入这个过滤器之前已经登录成功,直接放行,怎么判断有没有登录成功,就看Session中是否有user对象 */ public class AutoLoginFilter implements Filter { public void destroy() { } public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException { // 1.判断是否已登录 // 1.1将request对象强转成HttpServletRequest类型 HttpServletRequest rqs = (HttpServletRequest) request; // 1.2获取session对象 HttpSession session = rqs.getSession(); // 1.3获取session中存放的user User user = (User) session.getattribute("user"); // 1.4判断user是否为null if (user == null) { // 未登录 // 判断是否需要自动登录----->就看cookie中是否有"info" String info = CookieUtil.getCookieValue(rqs, "info"); if (info != null) { // 需要自动登录,如果不需要自动登录同样也放行 // 取出用户名和密码 String username = info.split("#")[0]; String password = info.split("#")[1]; // 调用业务层方法登录 UserService service = new UserService(); user = service.doLogin(username, password); // 很重要的一步，将user存放到session中 session.setAttribute("user", user); } } chain.doFilter(request, response); } public void init(FilterConfig fConfig) throws ServletException { } }
LogoutServlet.java
package com.servlet;
import java.io.IOException;
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 javax.servlet.http.HttpSession;
import com.utils.CookieUtil;
/**
* 处理注销功能servlet
*/
public class LogoutServlet extends HttpServlet {
private static final long serialVersionUID = 1L;
protected void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
//注销其实就是将用户从session中移出
HttpSession session = request.getSession();
//立即销毁Session,并且清楚客服端的cookie
session.invalidate();
Cookie cookie = CookieUtil.createCookie("info","hello", 0, request.getContextPath());
response.addCookie(cookie);
//跳转到登录页面
response.sendRedirect(request.getContextPath()+"/login.jsp");
}
protected void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
doGet(request, response);
}
}CookieUtil
package com.utils;
import javax.servlet.http.Cookie;
import javax.servlet.http.HttpServletRequest;
public class CookieUtil {
/**
* 创建并配置Cookie
* @param name cookie的name
* @param value cookie的value
* @param time 有效期，秒
* @param path 有效范围
* @return
*/
public static Cookie createCookie(String name,String value,int time,String path){
Cookie cookie = new Cookie(name, value);
//Cookie的一些其他设置，可以设置最大有效期，可以设置有效范围(在哪里能够获取到该Cookie信息)
//设置有效期
cookie.setMaxAge(time);
//设置有效范围
cookie.setPath(path);//只能在CookieDemo02这个Servlet中获取该Cookie的信息
return cookie;
}
/**
* 获取Cookie里面的值
*/
public static String getCookieValue(HttpServletRequest request,String cookieName){
Cookie[] cookies = request.getCookies();
String value = null;
if (cookies != null) {
for (Cookie cookie : cookies) {
if (cookieName.equals(cookie.getName())) {
//确实是咱们要获取的那个名为username的cookie对象
value = cookie.getValue();
}
}
}
return value;
}
}C3P0Utils.java
package com.utils; import java.sql.Connection; import java.sql.Preparedstatement; import java.sql.ResultSet; import java.sql.SQLException; import javax.sql.DataSource; import com.mchange.v2.c3p0.CombopooledDataSource; public class C3P0Utils { /** * c3p0连接池工具类 */ private static ComboPooledDataSource dataSource; static { dataSource=new ComboPooledDataSource(); } public static DataSource getDataSource() { return dataSource; } public static Connection getConnection() { Connection con=null; try { con= dataSource.getConnection(); } catch (SQLException e) { System.out.println(e); throw new runtimeexception("数据库链接异常,请联系技术人员"); } return con; } public static void close(ResultSet resultSet,PreparedStatement ps,Connection con) { if (resultSet!=null) { try { resultSet.close(); } catch (Exception e) { System.out.println(e); } } if (ps!=null) { try { ps.close(); } catch (Exception e) { System.out.println(e); } } if (con!=null) { try { con.close(); } catch (Exception e) { System.out.println(e); } } } }
数据库连接池配置文件
c3p0-config.xml
<?xml version="1.0" encoding="UTF-8"?>
<c3p0-config>
<default-config>
<property name="initialPoolSize">10</property>
<property name="user">root</property>
<property name="password">root</property>
<property name="jdbcUrl">jdbc:mysql://localhost:3306/autologin?characterEncoding=utf8</property>
<property name="driverClass">com.mysql.jdbc.Driver</property>
</default-config>
</c3p0-config>使用过滤器(Filter)实现用户自动登录
应用场景:现在大部分网站都支持一段时间类用户自动登陆功能,移动端APP应用几乎都需要自动登陆,试想一下如果你每天打开微信或者QQ等APP时每次都需要手动输入用户名密码然后在登录,内心早已是一万匹草泥马.所以说自动登录功能对于提高用户体验时非常重要的.
那么下面我们就来自己实现一个简单的用户自定登录案列吧!
自动登陆案列分析
使用过滤器(Filter)实现用户自动登录
应用场景:现在大部分网站都支持一段时间类用户自动登陆功能,移动端APP应用几乎都需要自动登陆,试想一下如果你每天打开微信或者QQ等APP时每次都需要手动输入用户名密码然后在登录,内心早已是一万匹草泥马.所以说自动登录功能对于提高用户体验时非常重要的.
那么下面我们就来自己实现一个简单的用户自定登录案列吧!
自动登陆案列分析
开发平台:win10 64位
开发语言:Java
开发工具:Eclipse Oxygen版(2018 3月发布) 服务器: tomcat 7.0 , jdk1.8 数据库:Mysql 5.5
相关工具包:
c3p0-0.9.1.2.jar(c3p0连接池jar包)commons-dbutils-1.4.jar(简化数据处理jar包,可以自己封装)jstl.jar(jstl jar包)mysql-connector-java-5.1.39-bin.jar(mysql驱动)standard.jar(jstl jar包)
1.准备数据
create database autologin;
use autologin;
create table user(
id int primary key auto_increment,
username varchar(20),
password varchar(20),
birthday date,
email varchar(60)
);
insert into user values(null,'Tom','123456','1990-10-18','[email protected]');
insert into user values(null,'Jack','123456','1921-07-01','[email protected]');
insert into user values(null,'Bob','123456','1990-02-22','[email protected]');前端页面 login.jsp
<%@page import="com.utils.CookieUtil"%>
<%@ page language="java" contentType="text/html; charset=UTF-8"
pageEncoding="UTF-8"%>
<%@taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c" %>
<!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=UTF-8">
<title>登录页面</title>
</head>
<body>
<%--如果用户已登录,直接掉转到首页 --%>
<c:if test="${not empty user }">
<jsp:forward page="/index.jsp"></jsp:forward>
</c:if>
<%--如果用户未登录就显示下面的页面 --%>
<form action="${pageContext.request.contextPath }/login" method="post">
用户名<input type="text" name="username"><br>
密码<input type="password" name="pwd"><br>
自动登录<input type="checkbox" name="auto" value="on"><br>
<input type="submit" value="登录">
</form>
</body>
</html>index.jsp
<%@page import="com.bean.User"%>
<%@ page language="java" contentType="text/html; charset=UTF-8"
pageEncoding="UTF-8"%>
<%@taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c" %>
<!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=UTF-8">
<title>首页</title>
</head>
<body>
<%--判断是否已登录，如果已登录则显示欢迎XXX登录 注销 购物车
如果未登录，则显示 注册 登录
怎么判断是否已登录?只要登录成功，就会将user对象存放到session中，所以判断session中是否有user就可以知道是否已登录
--%>
<c:if test="${not empty user }">
<h1>欢迎你回来${user.username }!</h1>
<a href="${pageContext.request.contextPath }/logout">注销</a>
<a href="${pageContext.request.contextPath }/car.jsp">购物车</a>
</c:if>
<c:if test="${empty user }">
<a href="${pageContext.request.contextPath }/register.jsp">注册</a>
<a href="${pageContext.request.contextPath }/login.jsp">登录</a>
</c:if>
</body>
</html>car.jsp
<%@ page language="java" contentType="text/html; charset=UTF-8"
pageEncoding="UTF-8"%>
<%@taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>Insert title here</title>
</head>
<body>
<c:if test="${empty user}">
<jsp:forward page="/login.jsp"></jsp:forward>
</c:if>
<c:if test="${not empty user}">
<h1>${user.username }欢迎来到我的购物车</h1>
</c:if>
</body>
</html>register.jsp
<%@ page language="java" contentType="text/html; charset=UTF-8"
pageEncoding="UTF-8"%>
<!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=UTF-8">
<title>注册页面</title>
</head>
<body>
<h1>欢迎加入我们!</h1>
</body>
</html>服务端代码
LoginServlet.java
package com.servlet;
import java.io.IOException;
import java.io.PrintWriter;
import javax.servlet.ServletContext;
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 javax.servlet.http.HttpSession;
import com.bean.User;
import com.service.UserService;
import com.utils.CookieUtil;
/**
* 处理用户登录的Servlet
*/
public class LoginServlet extends HttpServlet {
private static final long serialVersionUID = 1L;
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
response.setContentType("text/html;charset=utf-8");
String username = request.getParameter("username");
String password = request.getParameter("pwd");
String auto = request.getParameter("auto");
HttpSession session = request.getSession();
//调用业务层方法登录
UserService service=new UserService();
User user=service.doLogin(username,password);
System.out.println(user);
if (user!=null) {
//当用户选择自动登陆后,我们怎样才能实现用户自动登陆成功呢?首先将用户登录成功的用户名和密码存入cookie并发送到客户端
Cookie cookie = CookieUtil.createCookie("info",username+"#"+password,7*24*60*60,request.getContextPath());
//判断用户是否选择了自动登陆
if (!"on".equalsIgnoreCase(auto)) {
//如果用户没有选择自动登陆,则需要把cookie清空
cookie.setMaxAge(0);
}
//把cookie发送到客服端
response.addCookie(cookie);
//登录成功,把user存入session中
session.setAttribute("user",user);
response.sendRedirect(request.getContextPath()+"/index.jsp");
}else {
response.sendRedirect(request.getContextPath()+"/login.jsp");
}
}
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
doGet(request, response);
}
}UserService.java
package com.service;
import java.sql.SQLException;
import java.util.List;
import com.bean.User;
import com.dao.UserDao;
public class UserService {
public User doLogin(String username, String password) {
UserDao dao = new UserDao();
User user=null;
try {
user = dao.doLogin(username, password);
} catch (SQLException e) {
e.printStackTrace();
}
return user;
}
}UserDao.java
package com.dao;
import java.sql.SQLException;
import org.apache.commons.dbutils.QueryRunner;
import org.apache.commons.dbutils.handlers.BeanHandler;
import com.bean.User;
import com.utils.C3P0Utils;
public class UserDao {
public User doLogin(String username, String password) throws SQLException {
QueryRunner runner = new QueryRunner(C3P0Utils.getDataSource());
String sql = "select * from user where username=? and password=?";
User user = runner.query(sql, new BeanHandler<>(User.class), username, password);
return user;
}
}AutoLoginFilter.java
package com.filter;
import java.io.IOException;
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.HttpServletResponse;
import javax.servlet.http.HttpSession;
import com.bean.User;
import com.service.UserService;
import com.utils.CookieUtil;
/**
* 如果进入这个过滤器之前已经登录成功,直接放行,怎么判断有没有登录成功,就看Session中是否有user对象
*/
public class AutoLoginFilter implements Filter {
public void destroy() {
}
public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain)
throws IOException, ServletException {
// 1.判断是否已登录
// 1.1将request对象强转成HttpServletRequest类型
HttpServletRequest rqs = (HttpServletRequest) request;
// 1.2获取session对象
HttpSession session = rqs.getSession();
// 1.3获取session中存放的user
User user = (User) session.getAttribute("user");
// 1.4判断user是否为null
if (user == null) {
// 未登录
// 判断是否需要自动登录----->就看cookie中是否有"info"
String info = CookieUtil.getCookieValue(rqs, "info");
if (info != null) {
// 需要自动登录,如果不需要自动登录同样也放行
// 取出用户名和密码
String username = info.split("#")[0];
String password = info.split("#")[1];
// 调用业务层方法登录
UserService service = new UserService();
user = service.doLogin(username, password);
// 很重要的一步，将user存放到session中
session.setAttribute("user", user);
}
}
chain.doFilter(request, response);
}
public void init(FilterConfig fConfig) throws ServletException {
}
}LogoutServlet.java
package com.servlet;
import java.io.IOException;
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 javax.servlet.http.HttpSession;
import com.utils.CookieUtil;
/**
* 处理注销功能servlet
*/
public class LogoutServlet extends HttpServlet {
private static final long serialVersionUID = 1L;
protected void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
//注销其实就是将用户从session中移出
HttpSession session = request.getSession();
//立即销毁Session,并且清楚客服端的cookie
session.invalidate();
Cookie cookie = CookieUtil.createCookie("info","hello", 0, request.getContextPath());
response.addCookie(cookie);
//跳转到登录页面
response.sendRedirect(request.getContextPath()+"/login.jsp");
}
protected void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
doGet(request, response);
}
}工具类
CookieUtil
package com.utils;
import javax.servlet.http.Cookie;
import javax.servlet.http.HttpServletRequest;
public class CookieUtil {
/**
* 创建并配置Cookie
* @param name cookie的name
* @param value cookie的value
* @param time 有效期，秒
* @param path 有效范围
* @return
*/
public static Cookie createCookie(String name,String value,int time,String path){
Cookie cookie = new Cookie(name, value);
//Cookie的一些其他设置，可以设置最大有效期，可以设置有效范围(在哪里能够获取到该Cookie信息)
//设置有效期
cookie.setMaxAge(time);
//设置有效范围
cookie.setPath(path);//只能在CookieDemo02这个Servlet中获取该Cookie的信息
return cookie;
}
/**
* 获取Cookie里面的值
*/
public static String getCookieValue(HttpServletRequest request,String cookieName){
Cookie[] cookies = request.getCookies();
String value = null;
if (cookies != null) {
for (Cookie cookie : cookies) {
if (cookieName.equals(cookie.getName())) {
//确实是咱们要获取的那个名为username的cookie对象
value = cookie.getValue();
}
}
}
return value;
}
}C3P0Utils.java
package com.utils;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import javax.sql.DataSource;
import com.mchange.v2.c3p0.ComboPooledDataSource;
public class C3P0Utils {
/**
* c3p0连接池工具类
*/
private static ComboPooledDataSource dataSource;
static {
dataSource=new ComboPooledDataSource();
}
public static DataSource getDataSource() {
return dataSource;
}
public static Connection getConnection() {
Connection con=null;
try {
con= dataSource.getConnection();
} catch (SQLException e) {
System.out.println(e);
throw new RuntimeException("数据库链接异常,请联系技术人员");
}
return con;
}
public static void close(ResultSet resultSet,PreparedStatement ps,Connection con) {
if (resultSet!=null) {
try {
resultSet.close();
} catch (Exception e) {
System.out.println(e);
}
}
if (ps!=null) {
try {
ps.close();
} catch (Exception e) {
System.out.println(e);
}
}
if (con!=null) {
try {
con.close();
} catch (Exception e) {
System.out.println(e);
}
}
}
}数据库连接池配置文件
c3p0-config.xml
<?xml version="1.0" encoding="UTF-8"?>
<c3p0-config>
<default-config>
<property name="initialPoolSize">10</property>
<property name="user">root</property>
<property name="password">root</property>
<property name="jdbcUrl">jdbc:mysql://localhost:3306/autologin?characterEncoding=utf8</property>
<property name="driverClass">com.mysql.jdbc.Driver</property>
</default-config>
</c3p0-config>使用过滤器(Filter)实现用户自动登录
应用场景:现在大部分网站都支持一段时间类用户自动登陆功能,移动端APP应用几乎都需要自动登陆,试想一下如果你每天打开微信或者QQ等APP时每次都需要手动输入用户名密码然后在登录,内心早已是一万匹草泥马.所以说自动登录功能对于提高用户体验时非常重要的.
那么下面我们就来自己实现一个简单的用户自定登录案列吧!
自动登陆案列分析
使用过滤器(Filter)实现用户自动登录
应用场景:现在大部分网站都支持一段时间类用户自动登陆功能,移动端APP应用几乎都需要自动登陆,试想一下如果你每天打开微信或者QQ等APP时每次都需要手动输入用户名密码然后在登录,内心早已是一万匹草泥马.所以说自动登录功能对于提高用户体验时非常重要的.
那么下面我们就来自己实现一个简单的用户自定登录案列吧!
自动登陆案列分析
开发平台:win10 64位
开发语言:Java
开发工具:Eclipse Oxygen版(2018 3月发布) 服务器: tomcat 7.0 , jdk1.8 数据库:Mysql 5.5
相关工具包:
c3p0-0.9.1.2.jar(c3p0连接池jar包)commons-dbutils-1.4.jar(简化数据处理jar包,可以自己封装)jstl.jar(jstl jar包)mysql-connector-java-5.1.39-bin.jar(mysql驱动)standard.jar(jstl jar包)
1.准备数据
create database autologin;
use autologin;
create table user(
id int primary key auto_increment,
username varchar(20),
password varchar(20),
birthday date,
email varchar(60)
);
insert into user values(null,'Tom','123456','1990-10-18','[email protected]');
insert into user values(null,'Jack','123456','1921-07-01','[email protected]');
insert into user values(null,'Bob','123456','1990-02-22','[email protected]');前端页面 login.jsp
<%@page import="com.utils.CookieUtil"%>
<%@ page language="java" contentType="text/html; charset=UTF-8"
pageEncoding="UTF-8"%>
<%@taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c" %>
<!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=UTF-8">
<title>登录页面</title>
</head>
<body>
<%--如果用户已登录,直接掉转到首页 --%>
<c:if test="${not empty user }">
<jsp:forward page="/index.jsp"></jsp:forward>
</c:if>
<%--如果用户未登录就显示下面的页面 --%>
<form action="${pageContext.request.contextPath }/login" method="post">
用户名<input type="text" name="username"><br>
密码<input type="password" name="pwd"><br>
自动登录<input type="checkbox" name="auto" value="on"><br>
<input type="submit" value="登录">
</form>
</body>
</html>index.jsp
<%@page import="com.bean.User"%>
<%@ page language="java" contentType="text/html; charset=UTF-8"
pageEncoding="UTF-8"%>
<%@taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c" %>
<!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=UTF-8">
<title>首页</title>
</head>
<body>
<%--判断是否已登录，如果已登录则显示欢迎XXX登录 注销 购物车
如果未登录，则显示 注册 登录
怎么判断是否已登录?只要登录成功，就会将user对象存放到session中，所以判断session中是否有user就可以知道是否已登录
--%>
<c:if test="${not empty user }">
<h1>欢迎你回来${user.username }!</h1>
<a href="${pageContext.request.contextPath }/logout">注销</a>
<a href="${pageContext.request.contextPath }/car.jsp">购物车</a>
</c:if>
<c:if test="${empty user }">
<a href="${pageContext.request.contextPath }/register.jsp">注册</a>
<a href="${pageContext.request.contextPath }/login.jsp">登录</a>
</c:if>
</body>
</html>car.jsp
<%@ page language="java" contentType="text/html; charset=UTF-8"
pageEncoding="UTF-8"%>
<%@taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>Insert title here</title>
</head>
<body>
<c:if test="${empty user}">
<jsp:forward page="/login.jsp"></jsp:forward>
</c:if>
<c:if test="${not empty user}">
<h1>${user.username }欢迎来到我的购物车</h1>
</c:if>
</body>
</html>register.jsp
<%@ page language="java" contentType="text/html; charset=UTF-8"
pageEncoding="UTF-8"%>
<!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=UTF-8">
<title>注册页面</title>
</head>
<body>
<h1>欢迎加入我们!</h1>
</body>
</html>服务端代码
LoginServlet.java
package com.servlet;
import java.io.IOException;
import java.io.PrintWriter;
import javax.servlet.ServletContext;
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 javax.servlet.http.HttpSession;
import com.bean.User;
import com.service.UserService;
import com.utils.CookieUtil;
/**
* 处理用户登录的Servlet
*/
public class LoginServlet extends HttpServlet {
private static final long serialVersionUID = 1L;
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
response.setContentType("text/html;charset=utf-8");
String username = request.getParameter("username");
String password = request.getParameter("pwd");
String auto = request.getParameter("auto");
HttpSession session = request.getSession();
//调用业务层方法登录
UserService service=new UserService();
User user=service.doLogin(username,password);
System.out.println(user);
if (user!=null) {
//当用户选择自动登陆后,我们怎样才能实现用户自动登陆成功呢?首先将用户登录成功的用户名和密码存入cookie并发送到客户端
Cookie cookie = CookieUtil.createCookie("info",username+"#"+password,7*24*60*60,request.getContextPath());
//判断用户是否选择了自动登陆
if (!"on".equalsIgnoreCase(auto)) {
//如果用户没有选择自动登陆,则需要把cookie清空
cookie.setMaxAge(0);
}
//把cookie发送到客服端
response.addCookie(cookie);
//登录成功,把user存入session中
session.setAttribute("user",user);
response.sendRedirect(request.getContextPath()+"/index.jsp");
}else {
response.sendRedirect(request.getContextPath()+"/login.jsp");
}
}
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
doGet(request, response);
}
}UserService.java
package com.service;
import java.sql.SQLException;
import java.util.List;
import com.bean.User;
import com.dao.UserDao;
public class UserService {
public User doLogin(String username, String password) {
UserDao dao = new UserDao();
User user=null;
try {
user = dao.doLogin(username, password);
} catch (SQLException e) {
e.printStackTrace();
}
return user;
}
}UserDao.java
package com.dao;
import java.sql.SQLException;
import org.apache.commons.dbutils.QueryRunner;
import org.apache.commons.dbutils.handlers.BeanHandler;
import com.bean.User;
import com.utils.C3P0Utils;
public class UserDao {
public User doLogin(String username, String password) throws SQLException {
QueryRunner runner = new QueryRunner(C3P0Utils.getDataSource());
String sql = "select * from user where username=? and password=?";
User user = runner.query(sql, new BeanHandler<>(User.class), username, password);
return user;
}
}AutoLoginFilter.java
package com.filter;
import java.io.IOException;
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.HttpServletResponse;
import javax.servlet.http.HttpSession;
import com.bean.User;
import com.service.UserService;
import com.utils.CookieUtil;
/**
* 如果进入这个过滤器之前已经登录成功,直接放行,怎么判断有没有登录成功,就看Session中是否有user对象
*/
public class AutoLoginFilter implements Filter {
public void destroy() {
}
public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain)
throws IOException, ServletException {
// 1.判断是否已登录
// 1.1将request对象强转成HttpServletRequest类型
HttpServletRequest rqs = (HttpServletRequest) request;
// 1.2获取session对象
HttpSession session = rqs.getSession();
// 1.3获取session中存放的user
User user = (User) session.getAttribute("user");
// 1.4判断user是否为null
if (user == null) {
// 未登录
// 判断是否需要自动登录----->就看cookie中是否有"info"
String info = CookieUtil.getCookieValue(rqs, "info");
if (info != null) {
// 需要自动登录,如果不需要自动登录同样也放行
// 取出用户名和密码
String username = info.split("#")[0];
String password = info.split("#")[1];
// 调用业务层方法登录
UserService service = new UserService();
user = service.doLogin(username, password);
// 很重要的一步，将user存放到session中
session.setAttribute("user", user);
}
}
chain.doFilter(request, response);
}
public void init(FilterConfig fConfig) throws ServletException {
}
}LogoutServlet.java
package com.servlet;
import java.io.IOException;
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 javax.servlet.http.HttpSession;
import com.utils.CookieUtil;
/**
* 处理注销功能servlet
*/
public class LogoutServlet extends HttpServlet {
private static final long serialVersionUID = 1L;
protected void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
//注销其实就是将用户从session中移出
HttpSession session = request.getSession();
//立即销毁Session,并且清楚客服端的cookie
session.invalidate();
Cookie cookie = CookieUtil.createCookie("info","hello", 0, request.getContextPath());
response.addCookie(cookie);
//跳转到登录页面
response.sendRedirect(request.getContextPath()+"/login.jsp");
}
protected void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
doGet(request, response);
}
}工具类
CookieUtil
package com.utils;
import javax.servlet.http.Cookie;
import javax.servlet.http.HttpServletRequest;
public class CookieUtil {
/**
* 创建并配置Cookie
* @param name cookie的name
* @param value cookie的value
* @param time 有效期，秒
* @param path 有效范围
* @return
*/
public static Cookie createCookie(String name,String value,int time,String path){
Cookie cookie = new Cookie(name, value);
//Cookie的一些其他设置，可以设置最大有效期，可以设置有效范围(在哪里能够获取到该Cookie信息)
//设置有效期
cookie.setMaxAge(time);
//设置有效范围
cookie.setPath(path);//只能在CookieDemo02这个Servlet中获取该Cookie的信息
return cookie;
}
/**
* 获取Cookie里面的值
*/
public static String getCookieValue(HttpServletRequest request,String cookieName){
Cookie[] cookies = request.getCookies();
String value = null;
if (cookies != null) {
for (Cookie cookie : cookies) {
if (cookieName.equals(cookie.getName())) {
//确实是咱们要获取的那个名为username的cookie对象
value = cookie.getValue();
}
}
}
return value;
}
}C3P0Utils.java
package com.utils;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import javax.sql.DataSource;
import com.mchange.v2.c3p0.ComboPooledDataSource;
public class C3P0Utils {
/**
* c3p0连接池工具类
*/
private static ComboPooledDataSource dataSource;
static {
dataSource=new ComboPooledDataSource();
}
public static DataSource getDataSource() {
return dataSource;
}
public static Connection getConnection() {
Connection con=null;
try {
con= dataSource.getConnection();
} catch (SQLException e) {
System.out.println(e);
throw new RuntimeException("数据库链接异常,请联系技术人员");
}
return con;
}
public static void close(ResultSet resultSet,PreparedStatement ps,Connection con) {
if (resultSet!=null) {
try {
resultSet.close();
} catch (Exception e) {
System.out.println(e);
}
}
if (ps!=null) {
try {
ps.close();
} catch (Exception e) {
System.out.println(e);
}
}
if (con!=null) {
try {
con.close();
} catch (Exception e) {
System.out.println(e);
}
}
}
}数据库连接池配置文件
c3p0-config.xml
<?xml version="1.0" encoding="UTF-8"?>
<c3p0-config>
<default-config>
<property name="initialPoolSize">10</property>
<property name="user">root</property>
<property name="password">root</property>
<property name="jdbcUrl">jdbc:mysql://localhost:3306/autologin?characterEncoding=utf8</property>
<property name="driverClass">com.mysql.jdbc.Driver</property>
</default-config>
</c3p0-config>使用过滤器(Filter)实现用户自动登录
应用场景:现在大部分网站都支持一段时间类用户自动登陆功能,移动端APP应用几乎都需要自动登陆,试想一下如果你每天打开微信或者QQ等APP时每次都需要手动输入用户名密码然后在登录,内心早已是一万匹草泥马.所以说自动登录功能对于提高用户体验时非常重要的.
那么下面我们就来自己实现一个简单的用户自定登录案列吧!
自动登陆案列分析
开发平台:win10 64位
开发语言:Java
开发工具:Eclipse Oxygen版(2018 3月发布) 服务器: tomcat 7.0 , jdk1.8 数据库:Mysql 5.5
相关工具包:
c3p0-0.9.1.2.jar(c3p0连接池jar包)commons-dbutils-1.4.jar(简化数据处理jar包,可以自己封装)jstl.jar(jstl jar包)mysql-connector-java-5.1.39-bin.jar(mysql驱动)standard.jar(jstl jar包)
1.准备数据
create database autologin;
use autologin;
create table user(
id int primary key auto_increment,
username varchar(20),
password varchar(20),
birthday date,
email varchar(60)
);
insert into user values(null,'Tom','123456','1990-10-18','[email protected]');
insert into user values(null,'Jack','123456','1921-07-01','[email protected]');
insert into user values(null,'Bob','123456','1990-02-22','[email protected]');前端页面 login.jsp
<%@page import="com.utils.CookieUtil"%>
<%@ page language="java" contentType="text/html; charset=UTF-8"
pageEncoding="UTF-8"%>
<%@taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c" %>
<!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=UTF-8">
<title>登录页面</title>
</head>
<body>
<%--如果用户已登录,直接掉转到首页 --%>
<c:if test="${not empty user }">
<jsp:forward page="/index.jsp"></jsp:forward>
</c:if>
<%--如果用户未登录就显示下面的页面 --%>
<form action="${pageContext.request.contextPath }/login" method="post">
用户名<input type="text" name="username"><br>
密码<input type="password" name="pwd"><br>
自动登录<input type="checkbox" name="auto" value="on"><br>
<input type="submit" value="登录">
</form>
</body>
</html>index.jsp
<%@page import="com.bean.User"%>
<%@ page language="java" contentType="text/html; charset=UTF-8"
pageEncoding="UTF-8"%>
<%@taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c" %>
<!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=UTF-8">
<title>首页</title>
</head>
<body>
<%--判断是否已登录，如果已登录则显示欢迎XXX登录 注销 购物车
如果未登录，则显示 注册 登录
怎么判断是否已登录?只要登录成功，就会将user对象存放到session中，所以判断session中是否有user就可以知道是否已登录
--%>
<c:if test="${not empty user }">
<h1>欢迎你回来${user.username }!</h1>
<a href="${pageContext.request.contextPath }/logout">注销</a>
<a href="${pageContext.request.contextPath }/car.jsp">购物车</a>
</c:if>
<c:if test="${empty user }">
<a href="${pageContext.request.contextPath }/register.jsp">注册</a>
<a href="${pageContext.request.contextPath }/login.jsp">登录</a>
</c:if>
</body>
</html>car.jsp
<%@ page language="java" contentType="text/html; charset=UTF-8"
pageEncoding="UTF-8"%>
<%@taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>Insert title here</title>
</head>
<body>
<c:if test="${empty user}">
<jsp:forward page="/login.jsp"></jsp:forward>
</c:if>
<c:if test="${not empty user}">
<h1>${user.username }欢迎来到我的购物车</h1>
</c:if>
</body>
</html>register.jsp
<%@ page language="java" contentType="text/html; charset=UTF-8"
pageEncoding="UTF-8"%>
<!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=UTF-8">
<title>注册页面</title>
</head>
<body>
<h1>欢迎加入我们!</h1>
</body>
</html>服务端代码
LoginServlet.java
package com.servlet;
import java.io.IOException;
import java.io.PrintWriter;
import javax.servlet.ServletContext;
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 javax.servlet.http.HttpSession;
import com.bean.User;
import com.service.UserService;
import com.utils.CookieUtil;
/**
* 处理用户登录的Servlet
*/
public class LoginServlet extends HttpServlet {
private static final long serialVersionUID = 1L;
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
response.setContentType("text/html;charset=utf-8");
String username = request.getParameter("username");
String password = request.getParameter("pwd");
String auto = request.getParameter("auto");
HttpSession session = request.getSession();
//调用业务层方法登录
UserService service=new UserService();
User user=service.doLogin(username,password);
System.out.println(user);
if (user!=null) {
//当用户选择自动登陆后,我们怎样才能实现用户自动登陆成功呢?首先将用户登录成功的用户名和密码存入cookie并发送到客户端
Cookie cookie = CookieUtil.createCookie("info",username+"#"+password,7*24*60*60,request.getContextPath());
//判断用户是否选择了自动登陆
if (!"on".equalsIgnoreCase(auto)) {
//如果用户没有选择自动登陆,则需要把cookie清空
cookie.setMaxAge(0);
}
//把cookie发送到客服端
response.addCookie(cookie);
//登录成功,把user存入session中
session.setAttribute("user",user);
response.sendRedirect(request.getContextPath()+"/index.jsp");
}else {
response.sendRedirect(request.getContextPath()+"/login.jsp");
}
}
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
doGet(request, response);
}
}UserService.java
package com.service;
import java.sql.SQLException;
import java.util.List;
import com.bean.User;
import com.dao.UserDao;
public class UserService {
public User doLogin(String username, String password) {
UserDao dao = new UserDao();
User user=null;
try {
user = dao.doLogin(username, password);
} catch (SQLException e) {
e.printStackTrace();
}
return user;
}
}UserDao.java
package com.dao;
import java.sql.SQLException;
import org.apache.commons.dbutils.QueryRunner;
import org.apache.commons.dbutils.handlers.BeanHandler;
import com.bean.User;
import com.utils.C3P0Utils;
public class UserDao {
public User doLogin(String username, String password) throws SQLException {
QueryRunner runner = new QueryRunner(C3P0Utils.getDataSource());
String sql = "select * from user where username=? and password=?";
User user = runner.query(sql, new BeanHandler<>(User.class), username, password);
return user;
}
}AutoLoginFilter.java
package com.filter;
import java.io.IOException;
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.HttpServletResponse;
import javax.servlet.http.HttpSession;
import com.bean.User;
import com.service.UserService;
import com.utils.CookieUtil;
/**
* 如果进入这个过滤器之前已经登录成功,直接放行,怎么判断有没有登录成功,就看Session中是否有user对象
*/
public class AutoLoginFilter implements Filter {
public void destroy() {
}
public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain)
throws IOException, ServletException {
// 1.判断是否已登录
// 1.1将request对象强转成HttpServletRequest类型
HttpServletRequest rqs = (HttpServletRequest) request;
// 1.2获取session对象
HttpSession session = rqs.getSession();
// 1.3获取session中存放的user
User user = (User) session.getAttribute("user");
// 1.4判断user是否为null
if (user == null) {
// 未登录
// 判断是否需要自动登录----->就看cookie中是否有"info"
String info = CookieUtil.getCookieValue(rqs, "info");
if (info != null) {
// 需要自动登录,如果不需要自动登录同样也放行
// 取出用户名和密码
String username = info.split("#")[0];
String password = info.split("#")[1];
// 调用业务层方法登录
UserService service = new UserService();
user = service.doLogin(username, password);
// 很重要的一步，将user存放到session中
session.setAttribute("user", user);
}
}
chain.doFilter(request, response);
}
public void init(FilterConfig fConfig) throws ServletException {
}
}LogoutServlet.java
package com.servlet;
import java.io.IOException;
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 javax.servlet.http.HttpSession;
import com.utils.CookieUtil;
/**
* 处理注销功能servlet
*/
public class LogoutServlet extends HttpServlet {
private static final long serialVersionUID = 1L;
protected void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
//注销其实就是将用户从session中移出
HttpSession session = request.getSession();
//立即销毁Session,并且清楚客服端的cookie
session.invalidate();
Cookie cookie = CookieUtil.createCookie("info","hello", 0, request.getContextPath());
response.addCookie(cookie);
//跳转到登录页面
response.sendRedirect(request.getContextPath()+"/login.jsp");
}
protected void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
doGet(request, response);
}
}工具类
CookieUtil
package com.utils;
import javax.servlet.http.Cookie;
import javax.servlet.http.HttpServletRequest;
public class CookieUtil {
/**
* 创建并配置Cookie
* @param name cookie的name
* @param value cookie的value
* @param time 有效期，秒
* @param path 有效范围
* @return
*/
public static Cookie createCookie(String name,String value,int time,String path){
Cookie cookie = new Cookie(name, value);
//Cookie的一些其他设置，可以设置最大有效期，可以设置有效范围(在哪里能够获取到该Cookie信息)
//设置有效期
cookie.setMaxAge(time);
//设置有效范围
cookie.setPath(path);//只能在CookieDemo02这个Servlet中获取该Cookie的信息
return cookie;
}
/**
* 获取Cookie里面的值
*/
public static String getCookieValue(HttpServletRequest request,String cookieName){
Cookie[] cookies = request.getCookies();
String value = null;
if (cookies != null) {
for (Cookie cookie : cookies) {
if (cookieName.equals(cookie.getName())) {
//确实是咱们要获取的那个名为username的cookie对象
value = cookie.getValue();
}
}
}
return value;
}
}C3P0Utils.java
package com.utils;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import javax.sql.DataSource;
import com.mchange.v2.c3p0.ComboPooledDataSource;
public class C3P0Utils {
/**
* c3p0连接池工具类
*/
private static ComboPooledDataSource dataSource;
static {
dataSource=new ComboPooledDataSource();
}
public static DataSource getDataSource() {
return dataSource;
}
public static Connection getConnection() {
Connection con=null;
try {
con= dataSource.getConnection();
} catch (SQLException e) {
System.out.println(e);
throw new RuntimeException("数据库链接异常,请联系技术人员");
}
return con;
}
public static void close(ResultSet resultSet,PreparedStatement ps,Connection con) {
if (resultSet!=null) {
try {
resultSet.close();
} catch (Exception e) {
System.out.println(e);
}
}
if (ps!=null) {
try {
ps.close();
} catch (Exception e) {
System.out.println(e);
}
}
if (con!=null) {
try {
con.close();
} catch (Exception e) {
System.out.println(e);
}
}
}
}数据库连接池配置文件
c3p0-config.xml
<?xml version="1.0" encoding="UTF-8"?>
<c3p0-config>
<default-config>
<property name="initialPoolSize">10</property>
<property name="user">root</property>
<property name="password">root</property>
<property name="jdbcUrl">jdbc:mysql://localhost:3306/autologin?characterEncoding=utf8</property>
<property name="driverClass">com.mysql.jdbc.Driver</property>
</default-config>
</c3p0-config>
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