analysis servlet

@WebServlet("/cdiservlet")     
public class NewServlet extends HttpServlet {
    private Message message;

    @Override             ||重写doGet方法
    public void init() {
        message = new MessageB();    ||对message初始化
    }

    @Override
    public void doGet(HttpServletRequest request, HttpServletResponse response)
                  throws IOException {              ||抛出可能出现IO异常
        response.getWriter().write(message.get());   ||捕获可能发生的异常
    }
}

public interface Message {         ||servlet实现Message接口的一个对象实例
    public String get();
}.


public class MessageB implements Message { ||servlet创建以下对象的实例
 public MessageB() { 
} @Override public String get() {
 return "message B"; } }

response.getWriter().write(message.get());  ||捕获可能发生的异常