JavaWeb修改请求参数信息

客户端发送请求：http://localhost:8080/test/xxx.action?name="palading"&age=24

        HttpServlet类中调用：

        Map<String, String[]>map=request.getParameterMap();
        for(String key:map.keySet()){
        if(key.equals("name")){
        map.put("name",new String[]{"小明"});
        }
        }

        HttpServlet引发异常
        java.lang.IllegalStateException:No modifications are allowed to a locked ParameterMap

        默认情况下只能查看请求参数信息，不能修改参数信息。
        所以继承要HttpServletRequestWrapper重写getParameter方法：

public class MyHttpServletWrapp extends HttpServletRequestWrapper {
    HttpServletRequest request;

    public MyHttpServletWrapp(HttpServletRequest request) {
        super(request);
        this.request = request;
    }

    @Override
    public String getParameter(String name) {
        if ("name".equals(name))
            return "Test";
        return super.getParameter(name);
    }

}


新建过滤器类 implements Filter
public void doFilter(ServletRequest request,ServletResponse response,FilterChain chain)throws IOException,ServletException{
        MyHttpServletWrapp myHttpServletWrapp=new MyHttpServletWrapp((HttpServletRequest)request);

        重新包装发送请求
        chain.doFilter(myHttpServletWrapp,response);
        }

        在HttpServlet中获取请求参数信息 发现请求参数信息已经被改变
protected void doGet(HttpServletRequest request,HttpServletResponse response)throws ServletException,IOException{

        String name=request.getParameter("name");
        System.out.println(name);

        }