目录
- <?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>cpc</servlet-name>
- <servlet-class>com.example.servletdemo1.HelloServlet</servlet-class>
- <init-param>
- <param-name>tjrac</param-name>
- <param-value>2021tj</param-value>
- </init-param>
- <init-param>
- <param-name>hdu</param-name>
- <param-value>2022tj</param-value>
- </init-param>
- </servlet>
- <servlet-mapping>
- <servlet-name>cpc</servlet-name>
- <url-pattern>/cpc/*</url-pattern>
- </servlet-mapping>
- </web-app>
- package com.example.servletdemo1;
-
- import java.io.*;
- import java.util.Enumeration;
- import javax.servlet.ServletConfig;
- import javax.servlet.ServletContext;
- import javax.servlet.http.HttpServlet;
- import javax.servlet.ServletException;
- import javax.servlet.http.HttpServletRequest;
- import javax.servlet.http.HttpServletResponse;
-
-
- public class HelloServlet extends HttpServlet {
- private ServletConfig config;
-
- public void init(ServletConfig config) throws ServletException {
- this.config = config;
- }
-
- protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
- //根据key获取value
- String hduvalue = config.getInitParameter("hdu");
- System.out.println(hduvalue);
- //获取所有的key
- Enumeration<String> keys= config.getInitParameterNames();
- while(keys.hasMoreElements()){
- //获取每一个key
- String key= keys.nextElement();
- //根据key获取value
- String value = config.getInitParameter(key);
- System.out.println(key+","+value);
- }
- //获取Servlet的名称
- String servletName = config.getServletName();
- System.out.println(servletName);
- //获取ServletContext对象
- ServletContext servletContext = config.getServletContext();
- System.out.println(servletContext);
- }
-
- protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
- doGet(request, response);
- }
- }
- <?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>cpc</servlet-name>
- <servlet-class>com.example.servletdemo1.HelloServlet</servlet-class>
- <init-param>
- <param-name>tjrac</param-name>
- <param-value>2021tj</param-value>
- </init-param>
- <init-param>
- <param-name>hdu</param-name>
- <param-value>2022tj</param-value>
- </init-param>
- </servlet>
- <servlet-mapping>
- <servlet-name>cpc</servlet-name>
- <url-pattern>/cpc/*</url-pattern>
- </servlet-mapping>
- <context-param>
- <param-name>globalhdu</param-name>
- <param-value>global2022tj</param-value>
- </context-param>
- <context-param>
- <param-name>globaltjrac</param-name>
- <param-value>global2021tj</param-value>
- </context-param>
- </web-app>
- package com.example.servletdemo1;
-
- import java.io.*;
- import javax.servlet.ServletContext;
- import javax.servlet.http.HttpServlet;
- import javax.servlet.ServletException;
- import javax.servlet.http.HttpServletRequest;
- import javax.servlet.http.HttpServletResponse;
-
-
- public class HelloServlet extends HttpServlet {
-
- protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
- //1.获取ServletContext对象
- ServletContext context = getServletContext();
- //2.常用方法演示
- //获取全局配置参数
- String value = context.getInitParameter("globalhdu");
- System.out.println(value);
- //获取应用的虚拟目录
- String contextPath = context.getContextPath();
- System.out.println(contextPath);
- //根据虚拟目录获取绝对路径
- String realPath = context.getRealPath("/");
- System.out.println(realPath);
- String realPath1 = context.getRealPath("WEB-INF");
- System.out.println(realPath1);
- }
-
- protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
- doGet(request, response);
- }
- }
- <?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>cpc</servlet-name>
- <servlet-class>com.example.servletdemo1.HelloServlet</servlet-class>
- <init-param>
- <param-name>tjrac</param-name>
- <param-value>2021tj</param-value>
- </init-param>
- <init-param>
- <param-name>hdu</param-name>
- <param-value>2022tj</param-value>
- </init-param>
- </servlet>
- <servlet-mapping>
- <servlet-name>cpc</servlet-name>
- <url-pattern>/cpc/*</url-pattern>
- </servlet-mapping>
- <servlet>
- <servlet-name>cpcc</servlet-name>
- <servlet-class>com.example.servletdemo1.config</servlet-class>
- </servlet>
- <servlet-mapping>
- <servlet-name>cpcc</servlet-name>
- <url-pattern>/cpcc</url-pattern>
- </servlet-mapping>
- <context-param>
- <param-name>globalhdu</param-name>
- <param-value>global2022tj</param-value>
- </context-param>
- <context-param>
- <param-name>globaltjrac</param-name>
- <param-value>global2021tj</param-value>
- </context-param>
- </web-app>
- public class HelloServlet extends HttpServlet {
-
- protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
- ServletContext context = getServletContext();
- context.setAttribute("love","daan");
- }
-
- protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
- doGet(request, response);
- }
- }
- public class config extends HttpServlet {
-
- protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
- ServletContext context = getServletContext();
- Object love = context.getAttribute("love");
- System.out.println(love);
- }
-
- protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
- doGet(request, response);
- }
- }