Analysis servlet

时间:2021-10-11 21:33:24
@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";
}
}
@WebServlet("/cdiservlet")              ||使用CDI,servlet声明它对Message实例的依赖性,并让它由CDI运行时自动注入
public class NewServlet extends HttpServlet {
@Inject private Message message; @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
}
}