实验五：过滤器与监听器
一、实验目的
1.掌握过滤器的创建与配置方法；
2.掌握监听器的创建与配置方法；
二、实验内容
2.1 创建Web项目
1. 打开MyEclipse，创建一个Web Project，命名为ServletTest。
2.1 SecurityFilter
详细过程见securityFilter.rmvb
1.过滤器SecurityFilter的代码如下：
package filters;
import java.io.IOException;
import java.io.PrintWriter;
import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.http.HttpServletRequest;
public class SecurityFilter implements Filter {
private FilterConfig filterConfig;
public void destroy() {
}
public void doFilter(ServletRequest request, ServletResponse response, FilterChain filterChain) throws IOException, ServletException { HttpServletRequest httpRequest = (HttpServletRequest) request;
// 获得用户输入的密码
String pwdInput = httpRequest.getParameter("password");
// 获得filter配置参数中的rightpass的值
String rightPwd = filterConfig.getInitParameter("rightpass");
if (!rightPwd.equals(pwdInput)) {
PrintWriter out = response.getWriter();
out.println("
Wrong password! Please try again.
");
out.flush();
return;
}
filterChain.doFilter(request, response);
}
public void init(FilterConfig filterConfig) throws ServletException { this.filterConfig = filterConfig;
}
}
2.LoginServlet的主要代码如下：
package servlets;
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;
import javax.servlet.http.HttpSession;
public class LoginServlet extends HttpServlet {
/**
* Constructor of the object.
*/
public LoginServlet() {
super();
}
/**
* Destruction of the servlet.
*/
public void destroy() {
super.destroy(); // Just puts "destroy" string in log
// Put your code here
}
/**
* The doGet method of the servlet.
*
* 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
*/
