java中servlet实现登录验证
在做web开发的时候总是避免不了登录验证的，那么我们今天就将学习servlet的登录验证，相信很多朋友们都不了解如何才能实现登录验证，现在我们就去看看java中servlet实现登录验证的教程。
login.java:
package com.ncu;
import java.io.PrintWriter;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
public class login extends HttpServlet{
public void doGet(HttpServletRequest req,HttpServletResponse res){
try{
//res.setCharacterEncoding("utf-8");
res.setContentType("text/html;charset=gbk");
PrintWriter pw=res.getWriter();
//返回登录界面
pw.print("<html>");
pw.print("<head>");
pw.print("<title>登录界面</title></head>");
pw.print("<body>");
pw.print("<h1>用户登录界面</h1>");
pw.print("<form action='loginpro' method=post>");
pw.print("用户名：<input type=text name=userName><br>");
pw.print("密码：<input type=password name=Pwd><br>");
pw.print("<input type=submit value=submit>");
pw.print("</body></html>");
}catch(Exception e)
{
e.printStackTrace();
}
}
}
LoginPro.java:
package com.ncu;
import java.io.PrintWriter;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
public class LoginPro extends HttpServlet{
public void doPost(HttpServletRequest req,HttpServletResponse res){
try{
String user=req.getParameter("userName");
String pwd=req.getParameter("Pwd");
if(user==null){
user="";
}
if(pwd==null)
{
pwd="";
}
if(user.equals("nicolas")&&pwd.equals("nicolas")){
//用户和密码合法
//res.sendRedirect("wel");
// res.setCharacterEncoding("gbk");
// PrintWriter pw=res.getWriter();
// pw.print("恭喜你，登录成功！！");
res.sendRedirect("welcome");
}
else{
//不合法进行跳转
res.sendRedirect("login");//跳转到登录界面
}
}catch(Exception e)
{
e.printStackTrace();
}
}
}
Welcome.java:
package com.ncu;
import java.io.PrintWriter;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
public class Welcome extends HttpServlet{
public void doGet(HttpServletRequest req,HttpServletResponse res){
try{
res.setCharacterEncoding("gbk");
PrintWriter pw=res.getWriter();
pw.print("welcome，您好");
}catch(Exception e)
{
e.printStackTrace();
}
}
}
web.xml
<?xml version="1.0" encoding="UTF-8"?>
<web-app version="3.0"
xmlns="http://java.sun.com/xml/ns/javaee"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://java.sun.com/xml/ns/javaee
http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd">
<display-name></display-name>
<welcome-file-list>
<welcome-file>index.jsp</welcome-file>
</welcome-file-list>
<servlet>
<!-- 给你的servlet取名，任意的 -->
<servlet-name>hello</servlet-name>
<!-- 指明servlet的路径（包名+类名 -->
<servlet-class>com.ncu.Hello</servlet-class>
</servlet>
<servlet-mapping>
<!-- 这个servlet名必须和映射的一致 -->
<servlet-name>hello</servlet-name>
<!-- 这是在浏览器中输入的访问该servlet的url -->
<url-pattern>/nicolas</url-pattern>
</servlet-mapping>
<servlet>
<servlet-name>helloservlet</servlet-name>
<servlet-class>com.ncu.HelloServlet</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>helloservlet</servlet-name>
<url-pattern>/helloservlet</url-pattern>
</servlet-mapping>
<servlet>
<servlet-name>helloHttpServlet</servlet-name>
<servlet-class>com.ncu.helloHttpServlet</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>helloHttpServlet</servlet-name>
<url-pattern>/helloHttpServlet</url-pattern>
</servlet-mapping>
<servlet>
<servlet-name>login</servlet-name>
<servlet-class>com.ncu.login</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>login</servlet-name>
<url-pattern>/login</url-pattern>
</servlet-mapping>
<servlet>
<servlet-name>loginpro</servlet-name>
<servlet-class>com.ncu.LoginPro</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>loginpro</servlet-name>
<url-pattern>/loginpro</url-pattern>
</servlet-mapping>
<servlet>
<servlet-name>welcome</servlet-name>
<servlet-class>com.ncu.Welcome</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>welcome</servlet-name>
<url-pattern>/welcome</url-pattern>
</servlet-mapping>
</web-app>
看完本文关于java中servlet实现登录验证的教程后你觉得对你的工作和学习是不是有了很大的帮助呢？以上都是小编精心挑选的内容希望大家喜欢。
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