servletlogin.java

Java网络应用编程入门代码（朱喜福） 我觉得很好用

package myshop.servlet;

import java.io.IOException;

import javax.servlet.ServletException;
import javax.servlet.http.*;

/**
 * 处理用户登录的认证和根据认证结果重新定向用户
 */
public class ServletLogin extends HttpServlet {

  // 仅处理 HTTP Get 请求
  public void doGet(HttpServletRequest request, HttpServletResponse response) throws
    ServletException, IOException {
    process(request, response);
  }

  // 仅处理 HTTP Post 请求
  public void doPost(HttpServletRequest request, HttpServletResponse response) throws
    ServletException, IOException {
    process(request, response);
  }

  // 统一处理 Get 和 Post 方式请求
  private void process(HttpServletRequest request, HttpServletResponse response) throws
    ServletException, IOException {
    String username = request.getParameter("username"); //获得提交用户名参数的值
    String password = request.getParameter("password"); //获得提交密码参数的值
    if(username !=null && password!=null && //用户名密码都不能为空
       "admin".equals(username) && //用户名是“admin”
       "111111".equals(password)) { //密码是“111111”
      response.sendRedirect("/maintain/main.jsp"); //重订向用户到功能页面
      return; //结束判定流程
    } else {
      response.sendRedirect("/maintain/index.jsp"); //重订向用户到登陆页面
      return; //结束判定流程
    }
  }
}