几种spring 获取bean的方法
获得spring里注册Bean的四种方法，特别是第三种方法，简单：?
一：方法一（多在struts框架中）继承BaseDispatchAction?
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import com.mas.wawacommunity.wap.service.UserManager;
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public class BaseDispatchAction extends DispatchAction {
? ? /**
? ? * web应用上下文环境变量
? ? */
? ? protected WebApplicationContext ctx;
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? ? protected UserManager userMgr;
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? ? /**
? ? * 获得注册Bean ? ??
? ? * @param beanName String 注册Bean的名称
? ? * @return
? ? */
? ? protected final Object getBean(String beanName) {
? ? ? ? return ctx.getBean(beanName);
? ? }
?
? ? protected ActionForward unspecified(ActionMapping mapping, ActionForm form,
? ? ? ? ? ? ? javax.servlet.http.HttpServletRequest request,
? ? ? ? ? ? ? javax.servlet.http.HttpServletResponse response) { ? ??
? ? ? ? return mapping.findForward("index");
? ? }
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? ? public void setServlet(ActionServlet servlet) {
? ? ? ? this.servlet = servlet;
? ? ? ? this.ctx = WebApplicationContextUtils.getWebApplicationContext(servlet.getServletContext());
? ? ? ? this.userMgr = (UserManager) getBean("userManager");
? ? } ? ? ? ??
}
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二：方法二实现BeanFactoryAware?
一定要在spring.xml中加上:
<bean id="serviceLocator" singleton="true" />
当对serviceLocator实例时就自动设置BeanFactory,以便后来可直接用beanFactory
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public class ServiceLocator implements BeanFactoryAware {
? ? private static BeanFactory beanFactory = null;
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? ? private static ServiceLocator servlocator = null;
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? ? public void setBeanFactory(BeanFactory factory) throws BeansException {
? ? ? ? this.beanFactory = factory;
? ? }
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? ? public BeanFactory getBeanFactory() {
? ? ? ? return beanFactory;
? ? }
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? ? public static ServiceLocator getInstance() {
? ? ? ? if (servlocator == null)
? ? ? ? ? ? ? servlocator = (ServiceLocator) beanFactory.getBean("serviceLocator");
? ? ? ? return servlocator;
? ? }
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? ? /**
? ? * 根据提供的bean名称得到相应的服务类 ? ??
? ? * @param servName bean名称 ? ??
? ? */
? ? public static Object getService(String servName) {
? ? ? ? return beanFactory.getBean(servName);
? ? }
?
? ? /**
? ? * 根据提供的bean名称得到对应于指定类型的服务类
? ? * @param servName bean名称
? ? * @param clazz 返回的bean类型,若类型不匹配,将抛出异常
? ? */
? ? public static Object getService(String servName, Class clazz) {
? ? ? ? return beanFactory.getBean(servName, clazz);
? ? }
}
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action调用:?
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public class UserAction extends BaseAction implements Action,ModelDriven{
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? ? private Users user = new Users();
? ? protected ServiceLocator service = ServiceLocator.getInstance();
? ? UserService userService = (UserService)service.getService("userService");
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? ? public String execute() throws Exception { ? ? ? ??
? ? ? ? return SUCCESS;
? ? }
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? public Object getModel() {
? ? ? ? return user;
? ? } ? ??
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? ? public String getAllUser(){
? ? ? ? HttpServletRequest request = ServletActionContext.getRequest(); ? ? ? ??
? ? ? ? List ls=userService.LoadAllObject( Users.class );
? ? ? ? request.setAttribute("user",ls); ? ??
? ? ? ? this.setUrl("/yonghu.jsp");
? ? ? ? return SUCCESS;
? ? }
}
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三：方法三实现ApplicationContextAware?
一定要在spring.xml中加上:
<bean id="SpringContextUtil " singleton="true" />
当对SpringContextUtil 实例时就自动设置applicationContext,以便后来可直接用applicationContext
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public class SpringContextUtil implements ApplicationContextAware {
? private static ApplicationContext applicationContext; ? ? //Spring应用上下文环境
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? /**
? * 实现ApplicationContextAware接口的回调方法，设置上下文环境 ??
? * @param applicationContext
? * @throws BeansException
? */
? public void setApplicationContext(ApplicationContext applicationContext) throws BeansException {
? ? SpringContextUtil.applicationContext = applicationContext;
? }
?
? /**
? * @return ApplicationContext
? */
? public static ApplicationContext getApplicationContext() {
? ? return applicationContext;
? }
?
? /**
? * 获取对象 ??
? * @param name
? * @return Object 一个以所给名字注册的bean的实例
? * @throws BeansException
? */
? public static Object getBean(String name) throws BeansException {
? ? return applicationContext.getBean(name);
? }
?
? /**
? * 获取类型为requiredType的对象
? * 如果bean不能被类型转换，相应的异常将会被抛出（BeanNotOfRequiredTypeException）
? * @param name ? ? ? bean注册名
? * @param requiredType 返回对象类型
? * @return Object 返回requiredType类型对象
? * @throws BeansException
? */
? public static Object getBean(String name, Class requiredType) throws BeansException {
? ? return applicationContext.getBean(name, requiredType);
? }
?
? /**
? * 如果BeanFactory包含一个与所给名称匹配的bean定义，则返回true?
? * @param name
? * @return boolean
? */
? public static boolean containsBean(String name) {
? ? return applicationContext.containsBean(name);
? }
?
? /**
? * 判断以给定名字注册的bean定义是一个singleton还是一个prototype。
? * 如果与给定名字相应的bean定义没有被找到，将会抛出一个异常（NoSuchBeanDefinitionException） ??
? * @param name
? * @return boolean
? * @throws NoSuchBeanDefinitionException
? */
? public static boolean isSingleton(String name) throws NoSuchBeanDefinitionException {
? ? return applicationContext.isSingleton(name);
? }
?
? /**
? * @param name
? * @return Class 注册对象的类型
? * @throws NoSuchBeanDefinitionException
? */
? public static Class getType(String name) throws NoSuchBeanDefinitionException {
? ? return applicationContext.getType(name);
? }
?
? /**
? * 如果给定的bean名字在bean定义中有别名，则返回这些别名 ??
? * @param name
? * @return
? * @throws NoSuchBeanDefinitionException
? */
? public static String[] getAliases(String name) throws NoSuchBeanDefinitionException {
? ? return applicationContext.getAliases(name);
? }
}
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action调用：?
package com.anymusic.oa.webwork;
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import java.util.List;
import java.util.Map;
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import javax.servlet.http.HttpServletRequest;
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import com.anymusic.oa.commons.service.ServiceLocator;
import com.anymusic.oa.hibernate.pojo.Role;
import com.anymusic.oa.hibernate.pojo.Users;
import com.anymusic.oa.spring.IUserService;
import com.opensymphony.webwork.ServletActionContext;
import com.opensymphony.xwork.Action;
import com.opensymphony.xwork.ActionContext;
import com.opensymphony.xwork.ModelDriven;
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public class UserAction extends BaseAction implements Action,ModelDriven{
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? ? private Users user = new Users();?
?//不用再加载springContext.xml文件,因为在web.xml中配置了,在程序中启动是就有了. ? ?
? ? UserService userService = (UserService) SpringContextUtil.getBean("userService");
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? ? public String execute() throws Exception { ? ? ? ??
? ? ? ? return SUCCESS;
? ? }
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? public Object getModel() {
? ? ? ? return user;
? ? } ? ??
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? ? public String getAllUser(){
? ? ? ? HttpServletRequest request = ServletActionContext.getRequest(); ? ? ? ??
? ? ? ? List ls=userService.LoadAllObject( Users.class );
? ? ? ? request.setAttribute("user",ls); ? ??
? ? ? ? this.setUrl("/yonghu.jsp");
? ? ? ? return SUCCESS;
? ? }
}
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四.通过servlet 或listener设置spring的ApplicationContext,以便后来引用.
注意分别extends ?ContextLoaderListener和ContextLoaderServlet .然后就可用SpringContext来getBean.
覆盖原来在web.xml中配置的listener或servlet.
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public class SpringContext ?{
? private static ApplicationContext applicationContext; ? ? //Spring应用上下文环境
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? */
? public void setApplicationContext(ApplicationContext applicationContext) throws BeansException {
? ? SpringContextUtil.applicationContext = applicationContext;
? }
?
? /**
? * @return ApplicationContext
? */
? public static ApplicationContext getApplicationContext() {
? ? return applicationContext;
? }
?
?
? */
? public static Object getBean(String name) throws BeansException {
? ? return applicationContext.getBean(name);
? }
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}
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public class SpringContextLoaderListener extends ContextLoaderListener{ ?//
?public void contextInitialized(ServletContextEvent event) { ?
? super.contextInitialized(event);
? SpringContext.setApplicationContext(
? ? WebApplicationContextUtils.getWebApplicationContext(event.getServletContext())
? ? );
?}
}
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public class SpringContextLoaderServlet extends ContextLoaderServlet {
?private ContextLoader contextLoader;
? ? public void init() throws ServletException {
? ? ? ? this.contextLoader = createContextLoader();
? ? ? ? SpringContext.setApplicationContext(this.contextLoader.initWebApplicationContext(getServletContext()));
? ? }
}
