spring应用于web项目中
Posted hy7873
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目标:
在webapp启动的时候取到spring的applicationContext对象,并把applicationContext对象存到servletContext里面,在需要的时候直接从servletcontext里面拿出来用
步骤:
1、加入spring jar包
2、建一个bean:
package com.hy.bean; /** * * @author Administrator * */ public class Person { private String name; public String getName() { return name; } public void setName(String name) { this.name = name; } public void hello() { System.out.println("my name is " + name); } }
3、建立spring配置文件:
<?xml version="1.0" encoding="UTF-8"?> <beans xmlns="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd"> <bean name="person" class="com.hy.bean.Person"> <property name="name" value="wanghai"> </property> </bean> </beans>
4、写一个listener
package com.hy.listener; import javax.servlet.ServletContext; import javax.servlet.ServletContextEvent; import javax.servlet.ServletContextListener; import org.springframework.context.ApplicationContext; import org.springframework.context.support.ClassPathXmlApplicationContext; public class SpringContextListener implements ServletContextListener{ @Override public void contextDestroyed(ServletContextEvent arg0) { } @Override public void contextInitialized(ServletContextEvent contextEvent) { ServletContext context = contextEvent.getServletContext(); String config = context.getInitParameter("contextLocation"); ApplicationContext app = new ClassPathXmlApplicationContext(config); context.setAttribute("ApplicationContext", app); } }
注意:获取servletcontext ,获取初始化参数(spring配置文件的位置),得到一个applicationContext,存入servletcontext中
5、将listener配置到web.xml里面
<?xml version="1.0" encoding="UTF-8"?> <web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://java.sun.com/xml/ns/javaee" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd" version="3.0"> <context-param> <param-name>contextLocation</param-name> <param-value>applicationContext.xml</param-value> </context-param> <listener> <listener-class>com.hy.listener.SpringContextListener</listener-class> </listener> </web-app>
注意:这里讲spring配置文件的位置写到了初始化参数里面。
6、写一个测试:
package com.hy.servlet; import java.io.IOException; import javax.servlet.ServletContext; 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 com.hy.bean.Person; /** * Servlet implementation class TestServlet */ @WebServlet("/TestServlet") public class TestServlet extends HttpServlet { private static final long serialVersionUID = 1L; /** * @see HttpServlet#HttpServlet() */ public TestServlet() { super(); // TODO Auto-generated constructor stub } /** * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response) */ protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { ServletContext context = getServletContext(); ApplicationContext app = (ApplicationContext) context.getAttribute("ApplicationContext"); Person person = app.getBean(Person.class); person.hello(); } /** * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response) */ protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { // TODO Auto-generated method stub } }
注意:这里用了注解配置servlet,注解配置最低支持tomcat7 jdk6 xml3.0
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