我们经常会自定义servlet然后重写doget和dopost方法
public void doPost(HttpServletRequest request, HttpServletResponse response)throws ServletException, IOException {response.setContentType("text/html;charset=utf-8");ServletInputStream in = request.getInputStream();String s = IOUtils.toString(in, "utf-8");System.out.println(s);}
参数中有HttpServletRequest和HttpServletResponse他们都是接口,那么实现类是什么?
public class HttpServletResponseWrapper extends ServletResponseWrapperimplements HttpServletResponse {
实现类是ServletResponseWrapper,这个类中有一个ServletResponse成员,但是他是接口,实现类是ResponseFacade。
public class ServletResponseWrapper implements ServletResponse {private ServletResponse response;
在自定义的servlet中我们经常会设置字符编码。
response.setContentType("text/html;charset=utf-8");
他调用了ServletResponseWrapper的方法,,这个方法又调用了成员的方法。
@Overridepublic void setContentType(String type) {this.response.setContentType(type);}@Overridepublic void setContentType(String type) {if (isCommitted()) {return;}if (SecurityUtil.isPackageProtectionEnabled()){AccessController.doPrivileged(new SetContentTypePrivilegedAction(type));} else {response.setContentType(type);}}
终于知道了自定义servlet中response的实现类。。。
也会有想更换的念头。旅行,正好提供了这样一个机会,