介绍//登录
public User 登录(User 用户),throws SQLException {
QueryRunner qr =, new QueryRunner (DataSourceUtils.getDataSource ());
String sql =,“select 得到user where username =, ?,以及password =, ?“
return qr.query (sql, new BeanHandler (User.class) user.getUsername (), user.getPassword ());
}
UserService.java
public User 登录(User 用户){
try {
return ud.login(用户);
},catch (SQLException e), {//,TODO Auto-generated catch 块
e.printStackTrace ();
}
return 零;
} //登录
public void 登录(HttpServletRequest 请求,
HttpServletResponse 响应),throws IOException, IllegalAccessException,, InvocationTargetException, ServletException {
Map package com.yinhe.web.filter;
import java.io.IOException;
import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.ServletException;
与javax . servlet . servletrequest import ;
import javax.servlet.ServletResponse;
import javax.servlet.http.Cookie;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import com.yinhe.bean.User;
import com.yinhe.service.UserService;
public class AutoLoginFilter implements 过滤{br/祝辞@Override
doFilter (ServletRequest public void ;请求,,ServletResponse 反应,
FilterChain 链),throws IOException, ServletException {
HttpServletRequest req =, (HttpServletRequest)请求;
HttpServletResponse resp =, (HttpServletResponse)反应;//是否已登录
if (req.getSession () .getAttribute (“user"),==, null){//如果已登录,则啥都不干//判断饼干中有没有账户密码
饼干[],cookies =, req.getCookies ();
if (cookies !=, null) {
String username =,““
String userpass =,““
时间:for (Cookie Cookie 饼干),{
if (cookie.getName () .equals (“username")){//找到感兴趣的饼干
时间=username cookie.getValue ();
}
if (cookie.getName () .equals (“password")){//找到感兴趣的饼干
时间=userpass cookie.getValue ();
}
}
UserService us =, new UserService ();
User User =, new 用户();
user.setUsername(用户名);
user.setPassword (userpass);
if (us.login(用户),!=,null) {
req.getSession () .setAttribute (“user",,用户);
}
}
}
chain.doFilter(请求,响应);br/祝辞}
@Override
filterConfig public void init (FilterConfig ), throws ServletException {//,TODO Auto-generated method stubbr/祝辞}
@Override
public void 破坏(),{//,TODO Auto-generated method 存根
}
}
怎么在Java项目中利用servlet实现一个自动登录退出功能?相信很多没有经验的人对此束手无策,为此本文总结了问题出现的原因和解决方法,通过这篇文章希望你能解决这个问题。
<强> UserDao。java从数据库中查询用户名与密码
<强> UserServlet。java实现登录功能
<>强工具类:AutoLoginFilter。java用来实现自动登录
<>强前台:登录。jsp此单选框被选中下次访问即为自动登录
