Servlet 初始化参数（web.xml和@WebServlet）

1、通过web.xml方式

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns="http://xmlns.jcp.org/xml/ns/javaee"xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_4_0.xsd"version="4.0"><servlet><servlet-name>Hello07</servlet-name><servlet-class>com.csdn.servlet.InitParamServlet</servlet-class><init-param><param-name>uname</param-name><param-value>我是服务器</param-value></init-param></servlet><servlet-mapping><servlet-name>Hello07</servlet-name><url-pattern>/h07</url-pattern></servlet-mapping></web-app>

package com.csdn.servlet;
import jakarta.servlet.*;
import java.io.IOException;
public class InitParamServlet extends GenericServlet {private String uname;@Overridepublic void init() throws ServletException {//ServletConfig - 代表当前Servlet的配置信息ServletConfig config = getServletConfig();//获取初始化参数uname = config.getInitParameter("uname");}@Overridepublic void service(ServletRequest servletRequest, ServletResponse servletResponse) throws ServletException, IOException {System.out.println(uname);}
}

 2、通过@WebServlet注解方式

package com.csdn.servlet;
import jakarta.servlet.*;
import jakarta.servlet.annotation.WebInitParam;
import jakarta.servlet.annotation.WebServlet;
import java.io.IOException;
@WebServlet(urlPatterns = "/h07", initParams = {@WebInitParam(name = "uname", value = "我是服务器")
})
public class InitParamServlet extends GenericServlet {private String uname;@Overridepublic void init() throws ServletException {//ServletConfig - 代表当前Servlet的配置信息ServletConfig config = getServletConfig();//获取初始化参数uname = config.getInitParameter("uname");}@Overridepublic void service(ServletRequest servletRequest, ServletResponse servletResponse) throws ServletException, IOException {System.out.println(uname);}
}