【JavaWeb】 ServletConfig

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在Web.xml上的代码，作用配置Servlet

<servlet>    <description>This is the description of my J2EE component</description>    <display-name>This is the display name of my J2EE component</display-name>    <servlet-name>ServletDemo4</servlet-name>    <servlet-class>cn.itcast.domain.ServletDemo4</servlet-class>    <init-param>    <param-name>data1</param-name>    <param-value>1111</param-value>    </init-param>    <init-param>    <param-name>data2</param-name>    <param-value>2222</param-value>    </init-param>    <init-param>    <param-name>data3</param-name>    <param-value>3333</param-value>    </init-param>    <init-param>    <param-name>data4</param-name>    <param-value>4444</param-value>    </init-param>  </servlet>

ServletDemo4的代码如下

package cn.itcast.domain;import java.io.IOException;import java.io.PrintWriter;import java.util.Enumeration;import javax.servlet.ServletException;import javax.servlet.http.HttpServlet;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse;public class ServletDemo4 extends HttpServlet {<span style="white-space:pre"></span>/**<span style="white-space:pre"></span> * Constructor of the object.<span style="white-space:pre"></span> */<span style="white-space:pre"></span>public ServletDemo4() {<span style="white-space:pre"></span>super();<span style="white-space:pre"></span>}<span style="white-space:pre"></span>public void doGet(HttpServletRequest request, HttpServletResponse response)<span style="white-space:pre"></span>throws ServletException, IOException {<span style="white-space:pre"></span>response.setContentType("text/html");<span style="white-space:pre"></span>PrintWriter out = response.getWriter();<span style="white-space:pre"></span>String value =this.getServletConfig().getInitParameter("data");<span style="white-space:pre"></span>out.println(value);<span style="white-space:pre"></span>Enumeration e = this.getServletConfig().getInitParameterNames();<span style="white-space:pre"></span>while(e.hasMoreElements()){<span style="white-space:pre"></span>String name = (String) e.nextElement();<span style="white-space:pre"></span>String value1= this.getServletConfig().getInitParameter(name);<span style="white-space:pre"></span>out.println(name+"="+value1);<span style="white-space:pre"></span>}<span style="white-space:pre"></span>out.flush();<span style="white-space:pre"></span>out.close();<span style="white-space:pre"></span>}

打印结果为:data1=1111 data2=2222 data3=3333 data4=4444

问:this.getServletConfig().getInitParameter();是什么东西，怎么构成

就是MyEclipse在创建Servlet写了函数，有把ServletConfig封装进去.

如下图的封装

类似上图的封装

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