spring整合web
0 导入jar包
1 tomcat启动加载配置文件
servlet-->init(ServletConfig)--><load-on-startup>2
filter-->init(FilterConfig)-->web.xml 注册过滤器自动调用
listener-->ServletContextListner-->servletContext对象监听
spring提供监听器 ContextLoaderListener -->web.xml <listener><listener-class>...
如果只配置监听器,默认加载xml位置:/WEB-INF/applicationContext.xml
2 确定配置文件位置,通过系统初始化参数
ServletContext初始化参数 web.xml
<context-param>
<param-name>contextConfigLocation
<param-value>classpath:applicationContext.xml
xml配置文件
<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://xmlns.jcp.org/xml/ns/javaee" xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_3_1.xsd" id="WebApp_ID" version="3.1">
<!-- 设置配置文件路径 -->
<context-param>
<param-name>contextConfigLocation</param-name>
<param-value>classpath:applicationContext.xml</param-value>
</context-param>
<!-- 配置spring监听器,加载xml配置文件 -->
<listener>
<listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
</listener>
</web-app>
3从ServletContext作用域 获得spring容器(了解)
package com.itheima.web.servlet;
import java.io.IOException;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.springframework.context.ApplicationContext;
import org.springframework.web.context.WebApplicationContext;
import org.springframework.web.context.support.WebApplicationContextUtils;
import com.itheima.service.AccountService;
/**
* Servlet implementation class HellowServlet
*/
@WebServlet("/HellowServlet")
public class HellowServlet extends HttpServlet {
private static final long serialVersionUID = 1L;
public HellowServlet() {
// TODO Auto-generated constructor stub
}
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
//从applicationContext作用于(ServletContext)获得spring容器
//方式1:手动从作用域获取
ApplicationContext applicationContext=
(ApplicationContext) this.getServletContext().getAttribute(WebApplicationContext.ROOT_WEB_APPLICATION_CONTEXT_ATTRIBUTE);
//方式2通过工具获取
ApplicationContext applicationContext2=
WebApplicationContextUtils.getWebApplicationContext(this.getServletContext());
//操作
AccountService accountService= (AccountService)applicationContext.getBean("accountService",AccountService.class);
accountService.transfer("jack", "rose", 1000);
}
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
// TODO Auto-generated method stub
doGet(request, response);
}
}