Java纯手打web服务器（三）

概要：考虑到上一篇中的request和response对象的安全性，不允许servlt程序员在service方法中把servletRequest和servletResponse对象进行强转request和response对象,而访问到request和response对象中私有的方法，这里引入外观类：RequestFacade和ResponseFacade，只实现ServletResponse和ServletRequest中声明的方法

具体代码如下：

public class RequestFacade implements ServletRequest {

  private ServletRequest request = null;

  public RequestFacade(Request request) {
    this.request = request;
  }
。。。。。。
}

public class ResponseFacade implements ServletResponse {

  private ServletResponse response;
  public ResponseFacade(Response response) {
    this.response = response;
  }
。。。。。
}

将request和response对象作为私有变量在构造器是进行传入，用此方法进行保护。

分析器相应的代码修改如下：

Servlet servlet = null;
    RequestFacade requestFacade = new RequestFacade(request);
    ResponseFacade responseFacade = new ResponseFacade(response);
    try {
      servlet = (Servlet) myClass.newInstance();
      servlet.service((ServletRequest) requestFacade, (ServletResponse) responseFacade);
    }
    catch (Exception e) {
      System.out.println(e.toString());
    }