Java 请求参数错误异常处理

来源：互联网发布：丁丁打卡软件编辑：程序博客网时间：2024/05/17 01:10

package com.accp.filter;

import java.io.IOException;

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.HttpServlet;
import javax.servlet.http.HttpServletRequest;

public class MyFilter extends HttpServlet implements Filter {

public void doFilter(ServletRequest request, ServletResponse response,
FilterChain chain) throws IOException, ServletException {

  HttpServletRequest arg0 =(HttpServletRequest)request;
  arg0.getSession().setAttribute("eurl", arg0.getRequestURI());
  chain.doFilter(request, response);
    /***
     * 类需要继承HttpServlet 和实现接口 Filter (过滤器)
     * 添加一个doFilter 方法（右击选择 Source---- Override/mplement Methods）
     * 定义HttpServletRequest,变量arg0 接收 request （需要转换类型）
     * arg0.getSession().setAttribute("ErrorUrl", arg0.getRequestURI());
     */
}

public void init(FilterConfig filterConfig) throws ServletException {
// TODO Auto-generated method stub

}
}

------------------Web.Xml的配置
<filter>
<filter-name>names</filter-name>
<filter-class>com.accp.filter.MyFilter</filter-class>
</filter>

<filter-mapping>

<filter-name>names</filter-name>
<url-pattern>/*</url-pattern>
</filter-mapping>

<error-page>
<error-code>500</error-code>
<location>/Error.jsp</location>
</error-page>

<error-page>
<error-code>404</error-code>
<location>/NullPage.jsp</location>
</error-page>

------------------------错误页面
<%String str = (String)request.getSession().getAttribute("eurl");
  String strId= request.getParameter("item.id");
   Integer id = Integer.parseInt(strId);

  if(str.equals("/news/news.do")){

   response.sendRedirect("news.do?item.id="+id+"&opt=doUpdateNews");
  }else
  {
   response.sendRedirect(str+"?opt=doFind");
  }
%>