javawebsoa

做web开发,登录验证是免不了的,今天学习了servlet的登录验证,当然是很简单的,没有使用session,request等作用域对象,所以还是可以直接通过地址访问网页的。

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();
		}
	}
}


servletDemo工程代码下载地址:

 


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>


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