ServletConfig接口詳解

概述

1，servletConfig是servlet的配置對象，作用是獲取servlet的初始化參數

2，子類：genericServlet 、HttpServlet

常用方法

獲取ServletConfig對象：getServletConfig（）

獲取servlet初始化參數值：getInitParameter（String name）

獲取servletContext對象：getServletContext（）

獲取servlet名稱：getServletName（），即的值

配置web.xml

  <servlet>
  	<servlet-name>ServletConfig</servlet-name>
  	<servlet-class>com.demo06_servlet_config.test</servlet-class>
  	<!-- 初始化參數 -->
  	<init-param>
  		<param-name>encoding</param-name>
  		<param-value>utf-8</param-value>
  	</init-param>
	<!-- 可以配置多個初始化參數 -->
	<init-param>
		<param-name>ID</param-name>
		<param-value>001</param-value>
	</init-param>
  </servlet>
  <servlet-mapping>
  	<servlet-name>ServletConfig</servlet-name>
  	<url-pattern>/servlet_config</url-pattern>
  </servlet-mapping>
  

配置servlet文件

package com.demo06_servlet_config;

import java.io.IOException;
import java.util.Enumeration;

import javax.servlet.ServletConfig;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
//@WebServlet("/servlet_config")
public class test extends HttpServlet {
	private static final long serialVersionUID = 1L;
	protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		//獲取servlet對象
		ServletConfig sc = this.getServletConfig();
		//獲取servlet名稱。就是配置文件中的servlet-name
		String name = sc.getServletName();
		//獲取初始化參數
		String value = sc.getInitParameter("ID");
		response.getWriter().println("========獲取servlet名稱測試====");
		response.getWriter().println(name);
		response.getWriter().println("======獲取指定初始化參數的值測試====");
		response.getWriter().println(value);
		response.getWriter().println("========獲取所有初始化名稱測試====");
		//獲取初始化參數名稱，因爲返回值是String泛型，所以泛型接收
		Enumeration<String> er = sc.getInitParameterNames();
		while(er.hasMoreElements()) {
			String name02 = er.nextElement();
			String value02 = sc.getInitParameter(name02);
			response.getWriter().println(name02);
			response.getWriter().println(value02);
		}
	}
	protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		doGet(request, response);
	}
}

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