servlet3.0註解@WebInitParam和@WebServlet

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轉自：http://blog.csdn.net/qq924862077/article/details/52883973?locationNum=2&fps=1

在以前的servlet中我們初始化一些參數都是配置在web.xml中的，自從servlet3.0之後給我們提供了註解@WebServlet和@WebInitParam，@WebServlet是用來配置servlet的屬性的，@WebInitParam是用來配置一些初始化屬性的。

@WebServlet和@WebInitParam使用如下：

package roseindia.net;  import java.io.IOException;  import java.io.PrintWriter;  import javax.servlet.ServletConfig;  import javax.servlet.ServletException;  import javax.servlet.annotation.WebServlet;  import javax.servlet.annotation.WebInitParam;  import javax.servlet.http.HttpServlet;  import javax.servlet.http.HttpServletRequest;  import javax.servlet.http.HttpServletResponse;    @WebServlet(      name = "WebInitParamExample", urlPatterns = {"/hello"}      ,initParams = {      @WebInitParam(name= "Site :", value="http://roseindia.net"),      @WebInitParam(name= "Rose", value= "India"),      }  )  public class WebInitParamExample extends HttpServlet{      public void doGet(HttpServletRequest request, HttpServletResponse response)      throws ServletException, IOException      {          response.setContentType("text/html");          PrintWriter out = response.getWriter();          out.println("<h2>Init Param Servlet Example</h2>");          ServletConfig config= getServletConfig();          String pValue= config.getInitParameter("Site :");          out.println("Param Value : "+pValue);          String pValue1= config.getInitParameter("Rose");          out.println("<br>Param Value : "+pValue1);          out.close();      }  }  

如果在web.xml中配置則如下：

<?xml version="1.0" encoding="UTF-8"?>  <web-app id="WebApp_ID" version="2.4" xmlns="http://java.sun.com/xml/ns/j2ee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://java.sun.com/xml/ns/j2ee http://java.sun.com/xml/ns/j2ee/web-app_2_4.xsd">      <display-name>servletAnnotationExample</display-name>      <servlet>          <servlet-name>WebInitParamExample</servlet-name>          <servlet-class>roseindia.net.WebInitParamExample</servlet-class>          <init-param>              <param-name>Site :</param-name>              <param-value>http://roseindia.net</param-value>          </init-param>      </servlet>      <servlet-mapping>          <servlet-name>WebInitParamExample</servlet-name>          <url-pattern>/hello</url-pattern>      </servlet-mapping>  </web-app> 

 

servlet3.0註解@WebInitParam和@WebServlet