📄 checkuserid.java
字号:
package com.xp1204.ajax;
import java.io.IOException;
import java.io.PrintWriter;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
/**
* @author xp1204 E-mail:xp1204@163.com
* @version 创建时间：Jun 28, 2007 9:59:17 AM
* 类说明
*/
public class CheckUserId extends HttpServlet {
/**
* Constructor of the object.
*/
public CheckUserId() {
super();
}
/**
* Destruction of the servlet. <br>
*/
public void destroy() {
super.destroy(); // Just puts "destroy" string in log
// Put your code here
}
/**
* The doGet method of the servlet. <br>
*
* This method is called when a form has its tag value method equals to get.
*
* @param request the request send by the client to the server
* @param response the response send by the server to the client
* @throws ServletException if an error occurred
* @throws IOException if an error occurred
*/
public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
response.setContentType("text/xml; charset=utf-8");
PrintWriter out = response.getWriter();
//这里就是检查用户名是否已经存在......你们可能要连接数据库之类的。。。。
//我这里就指定admin,xp1204,china为存在的用户
String userId = request.getParameter("userid");
if ("admin".equals(userId) || "xp1204".equals(userId) || "china".equals(userId)){
//这里就要返回错误信息了，用户名存在,应该是个xml格式的串
out.println("<?xml version='1.0' encoding='utf-8'?><message>您要注册的用户名 "+userId+" 已经存在了，请使用其他用户名!</message>");
//这里就完了，上面的信息我们在jsp中去获取他显示出来....
}else{
//这里就要返回正确信息了，用户名可以使用,应该是个xml格式的串
out.println("<?xml version='1.0' encoding='utf-8'?><message>恭喜您，您的用户名还没有被人使用!</message>");
}
out.close();
}
/**
* The doPost method of the servlet. <br>
*
* This method is called when a form has its tag value method equals to post.
*
* @param request the request send by the client to the server
* @param response the response send by the server to the client
* @throws ServletException if an error occurred
* @throws IOException if an error occurred
*/
public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
response.setContentType("text/html");
PrintWriter out = response.getWriter();
out
.println("<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01 Transitional//EN\">");
out.println("<HTML>");
out.println(" <HEAD><TITLE>A Servlet</TITLE></HEAD>");
out.println(" <BODY>");
out.print(" This is ");
out.print(this.getClass());
out.println(", using the POST method");
out.println(" </BODY>");
out.println("</HTML>");
out.flush();
out.close();
}
/**
* Initialization of the servlet. <br>
*
* @throws ServletException if an error occure
*/
public void init() throws ServletException {
// Put your code here
}
}
⌨️ 快捷键说明
复制代码
Ctrl + C
搜索代码
Ctrl + F
全屏模式
F11
切换主题
Ctrl + Shift + D
显示快捷键
?
增大字号
Ctrl + =
减小字号
Ctrl + -