ServletConfig对象.

• 是什么

  ServletConfig是javax.servlet.包下的一个接口，ServletConfig它是Servlet的一个配置对象；

  ServletConfig是由tomcat容器创建，通过init方法传入给Servlet；

• ServletConfig对象如何获取?

  在GenericServlet里面定义了：

public ServletConfig getServletConfig() {return this.config;
}

• 常用方法

getInitParameter(String parameterName); //根据参数名称获取指定的参数值
getInitParameterNames(); //获取所有的参数名称

  在web.xml文件中配置一下：

<servlet><servlet-name>ServletConfigServlet</servlet-name><servlet-class>com.by.servlet.ServletConfigServlet</servlet-class><init-param><param-name>username</param-name><param-value>Tom</param-value></init-param><init-param><param-name>password</param-name><param-value>123</param-value></init-param></servlet><servlet-mapping><servlet-name>ServletConfigServlet</servlet-name><url-pattern>/servletConfigServlet</url-pattern></servlet-mapping>

 在ServletConfigServlet这个类中调用一下：

/** Copyright (c) 2020, 2023,  All rights reserved.**/
package com.by.servlet;import javax.servlet.ServletConfig;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;/*** <p>Project: JavaWeb-Servlet - ServletConfigServlet</p>* <p>Powered by scl On 2023-12-26 15:52:05</p>* <p>描述：<p>** @author 孙臣龙 [[e-mail]]* @version 1.0* @since 17*/
public class ServletConfigServlet extends HttpServlet {@Overrideprotected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {doPost(req, resp);}@Overrideprotected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {ServletConfig servletConfig = getServletConfig();String username = servletConfig.getInitParameter("username");String password = servletConfig.getInitParameter("password");System.out.println(username+password);}
}

结果展示：