Java_web开发_SSH spring中取得Bean实例的方法 .（很强大，不能不转）

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

 

[java] view plaincopyprint?

1. import com.mas.wawacommunity.wap.service.UserManager;  
2.    
3. public class BaseDispatchAction extends DispatchAction {  
4.     /** 
5.     * web应用上下文环境变量 
6.     */  
7.     protected WebApplicationContext ctx;  
8.    
9.     protected UserManager userMgr;  
10.    
11.     /** 
12.     * 获得注册Bean      
13.     * @param beanName String 注册Bean的名称 
14.     * @return 
15.     */  
16.     protected final Object getBean(String beanName) {  
17.         return ctx.getBean(beanName);  
18.     }  
19.    
20.     protected ActionForward unspecified(ActionMapping mapping, ActionForm form,  
21.               javax.servlet.http.HttpServletRequest request,  
22.               javax.servlet.http.HttpServletResponse response) {       
23.         return mapping.findForward("index");  
24.     }  
25.    
26.     public void setServlet(ActionServlet servlet) {  
27.         this.servlet = servlet;  
28.         this.ctx = WebApplicationContextUtils.getWebApplicationContext(servlet.getServletContext());  
29.         this.userMgr = (UserManager) getBean("userManager");  
30.     }           
31. }  

import com.mas.wawacommunity.wap.service.UserManager; public class BaseDispatchAction extends DispatchAction { /** * web应用上下文环境变量 */ protected WebApplicationContext ctx; protected UserManager userMgr; /** * 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"); } public void setServlet(ActionServlet servlet) { this.servlet = servlet; this.ctx = WebApplicationContextUtils.getWebApplicationContext(servlet.getServletContext()); this.userMgr = (UserManager) getBean("userManager"); } }  

二：方法二实现BeanFactoryAware
一定要在spring.xml中加上:
<bean id="serviceLocator" class="项目中ServiceLocator的类路径比如：com.am.oa.commons.service.SpringContextUtil " singleton="true" />
当对serviceLocator实例时就自动设置BeanFactory,以便后来可直接用beanFactory

[java] view plaincopyprint?

1. public class ServiceLocator implements BeanFactoryAware {  
2.     private static BeanFactory beanFactory = null;  
3.    
4.     private static ServiceLocator servlocator = null;  
5.    
6.     public void setBeanFactory(BeanFactory factory) throws BeansException {  
7.         this.beanFactory = factory;  
8.     }  
9.    
10.     public BeanFactory getBeanFactory() {  
11.         return beanFactory;  
12.     }  
13.    
14.      
15.     public static ServiceLocator getInstance() {  
16.         if (servlocator == null)  
17.               servlocator = (ServiceLocator) beanFactory.getBean("serviceLocator");  
18.         return servlocator;  
19.     }  
20.    
21.     /** 
22.     * 根据提供的bean名称得到相应的服务类      
23.     * @param servName bean名称      
24.     */  
25.     public static Object getService(String servName) {  
26.         return beanFactory.getBean(servName);  
27.     }  
28.    
29.     /** 
30.     * 根据提供的bean名称得到对应于指定类型的服务类 
31.     * @param servName bean名称 
32.     * @param clazz 返回的bean类型,若类型不匹配,将抛出异常 
33.     */  
34.     public static Object getService(String servName, Class clazz) {  
35.         return beanFactory.getBean(servName, clazz);  
36.     }  
37. }  

public class ServiceLocator implements BeanFactoryAware { private static BeanFactory beanFactory = null; private static ServiceLocator servlocator = null; public void setBeanFactory(BeanFactory factory) throws BeansException { this.beanFactory = factory; } public BeanFactory getBeanFactory() { return beanFactory; } public static ServiceLocator getInstance() { if (servlocator == null) servlocator = (ServiceLocator) beanFactory.getBean("serviceLocator"); return servlocator; } /** * 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); }}  

action调用:

 

[java] view plaincopyprint?

1. public class UserAction extends BaseAction implements Action,ModelDriven{  
2.       
3.     private Users user = new Users();  
4.     protected ServiceLocator service = ServiceLocator.getInstance();  
5.     UserService userService = (UserService)service.getService("userService");  
6.    
7.     public String execute() throws Exception {           
8.         return SUCCESS;  
9.     }  
10.    
11.   public Object getModel() {  
12.         return user;  
13.     }       
14.       
15.     public String getAllUser(){  
16.         HttpServletRequest request = ServletActionContext.getRequest();           
17.         List ls=userService.LoadAllObject( Users.class );  
18.         request.setAttribute("user",ls);       
19.         this.setUrl("/yonghu.jsp");  
20.         return SUCCESS;  
21.     }  
22. }  

public class UserAction extends BaseAction implements Action,ModelDriven{ private Users user = new Users(); protected ServiceLocator service = ServiceLocator.getInstance(); UserService userService = (UserService)service.getService("userService"); public String execute() throws Exception { return SUCCESS; } public Object getModel() { return user; } public String getAllUser(){ HttpServletRequest request = ServletActionContext.getRequest(); List ls=userService.LoadAllObject( Users.class ); request.setAttribute("user",ls); this.setUrl("/yonghu.jsp"); return SUCCESS; }}  

三：方法三实现ApplicationContextAware
一定要在spring.xml中加上:
<bean id="SpringContextUtil " class="项目中applicationContext的类路径比如：com.am.oa.commons.service.SpringContextUtil " singleton="true" />
当对SpringContextUtil 实例时就自动设置applicationContext,以便后来可直接用applicationContext
 

[java] view plaincopyprint?

1. public class SpringContextUtil implements ApplicationContextAware {  
2.   private static ApplicationContext applicationContext;     //Spring应用上下文环境  
3.    
4.   /** 
5.   * 实现ApplicationContextAware接口的回调方法，设置上下文环境    
6.   * @param applicationContext 
7.   * @throws BeansException 
8.   */  
9.   public void setApplicationContext(ApplicationContext applicationContext) throws BeansException {  
10.     SpringContextUtil.applicationContext = applicationContext;  
11.   }  
12.    
13.   /** 
14.   * @return ApplicationContext 
15.   */  
16.   public static ApplicationContext getApplicationContext() {  
17.     return applicationContext;  
18.   }  
19.    
20.   /** 
21.   * 获取对象    
22.   * @param name 
23.   * @return Object 一个以所给名字注册的bean的实例 
24.   * @throws BeansException 
25.   */  
26.   public static Object getBean(String name) throws BeansException {  
27.     return applicationContext.getBean(name);  
28.   }  
29.    
30.   /** 
31.   * 获取类型为requiredType的对象 
32.   * 如果bean不能被类型转换，相应的异常将会被抛出（BeanNotOfRequiredTypeException） 
33.   * @param name       bean注册名 
34.   * @param requiredType 返回对象类型 
35.   * @return Object 返回requiredType类型对象 
36.   * @throws BeansException 
37.   */  
38.   public static Object getBean(String name, Class requiredType) throws BeansException {  
39.     return applicationContext.getBean(name, requiredType);  
40.   }  
41.    
42.   /** 
43.   * 如果BeanFactory包含一个与所给名称匹配的bean定义，则返回true  
44.   * @param name 
45.   * @return boolean 
46.   */  
47.   public static boolean containsBean(String name) {  
48.     return applicationContext.containsBean(name);  
49.   }  
50.    
51.   /** 
52.   * 判断以给定名字注册的bean定义是一个singleton还是一个prototype。 
53.   * 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）    
54.   * @param name 
55.   * @return boolean 
56.   * @throws NoSuchBeanDefinitionException 
57.   */  
58.   public static boolean isSingleton(String name) throws NoSuchBeanDefinitionException {  
59.     return applicationContext.isSingleton(name);  
60.   }  
61.    
62.   /** 
63.   * @param name 
64.   * @return Class 注册对象的类型 
65.   * @throws NoSuchBeanDefinitionException 
66.   */  
67.   public static Class getType(String name) throws NoSuchBeanDefinitionException {  
68.     return applicationContext.getType(name);  
69.   }  
70.    
71.   /** 
72.   * 如果给定的bean名字在bean定义中有别名，则返回这些别名    
73.   * @param name 
74.   * @return 
75.   * @throws NoSuchBeanDefinitionException 
76.   */  
77.   public static String[] getAliases(String name) throws NoSuchBeanDefinitionException {  
78.     return applicationContext.getAliases(name);  
79.   }  
80. }  

public class SpringContextUtil implements ApplicationContextAware { private static ApplicationContext applicationContext; //Spring应用上下文环境 /** * 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); }}  

 

action调用： 

[java] view plaincopyprint?

1. package com.anymusic.oa.webwork;  
2.    
3. import java.util.List;  
4. import java.util.Map;  
5.    
6. import javax.servlet.http.HttpServletRequest;  
7.    
8. import com.anymusic.oa.commons.service.ServiceLocator;  
9. import com.anymusic.oa.hibernate.pojo.Role;  
10. import com.anymusic.oa.hibernate.pojo.Users;  
11. import com.anymusic.oa.spring.IUserService;  
12. import com.opensymphony.webwork.ServletActionContext;  
13. import com.opensymphony.xwork.Action;  
14. import com.opensymphony.xwork.ActionContext;  
15. import com.opensymphony.xwork.ModelDriven;  
16.    
17. public class UserAction extends BaseAction implements Action,ModelDriven{  
18.       
19.     private Users user = new Users();   
20.  //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.      
21.     UserService userService = (UserService) SpringContextUtil.getBean("userService");  
22.       
23.     public String execute() throws Exception {           
24.         return SUCCESS;  
25.     }  
26.    
27.   public Object getModel() {  
28.         return user;  
29.     }       
30.       
31.     public String getAllUser(){  
32.         HttpServletRequest request = ServletActionContext.getRequest();           
33.         List ls=userService.LoadAllObject( Users.class );  
34.         request.setAttribute("user",ls);       
35.         this.setUrl("/yonghu.jsp");  
36.         return SUCCESS;  
37.     }  
38. }  

package com.anymusic.oa.webwork; import java.util.List;import java.util.Map; import javax.servlet.http.HttpServletRequest; 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; public class UserAction extends BaseAction implements Action,ModelDriven{ 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"); public String execute() throws Exception { return SUCCESS; } public Object getModel() { return user; } public String getAllUser(){ HttpServletRequest request = ServletActionContext.getRequest(); List ls=userService.LoadAllObject( Users.class ); request.setAttribute("user",ls); this.setUrl("/yonghu.jsp"); return SUCCESS; }}  

 

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.

[java] view plaincopyprint?

1. public class SpringContext  {  
2.   private static ApplicationContext applicationContext;     //Spring应用上下文环境  
3.    
4.   
5.   */  
6.   public void setApplicationContext(ApplicationContext applicationContext) throws BeansException {  
7.     SpringContextUtil.applicationContext = applicationContext;  
8.   }  
9.    
10.   /** 
11.   * @return ApplicationContext 
12.   */  
13.   public static ApplicationContext getApplicationContext() {  
14.     return applicationContext;  
15.   }  
16.    
17.   
18.   */  
19.   public static Object getBean(String name) throws BeansException {  
20.     return applicationContext.getBean(name);  
21.   }  
22.   
23. }  
24.   
25. public class SpringContextLoaderListener extends ContextLoaderListener{  //  
26.  public void contextInitialized(ServletContextEvent event) {    
27.   super.contextInitialized(event);  
28.   SpringContext.setApplicationContext(  
29.     WebApplicationContextUtils.getWebApplicationContext(event.getServletContext())  
30.     );  
31.  }  
32. }  
33.   
34. public class SpringContextLoaderServlet extends ContextLoaderServlet {  
35.  private ContextLoader contextLoader;  
36.     public void init() throws ServletException {  
37.         this.contextLoader = createContextLoader();  
38.         SpringContext.setApplicationContext(this.contextLoader.initWebApplicationContext(getServletContext()));  
39.     }  
40. }  

public class SpringContext { private static ApplicationContext applicationContext; //Spring应用上下文环境 */ 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); }}public class SpringContextLoaderListener extends ContextLoaderListener{ // public void contextInitialized(ServletContextEvent event) { super.contextInitialized(event); SpringContext.setApplicationContext( WebApplicationContextUtils.getWebApplicationContext(event.getServletContext()) ); }}public class SpringContextLoaderServlet extends ContextLoaderServlet { private ContextLoader contextLoader; public void init() throws ServletException { this.contextLoader = createContextLoader(); SpringContext.setApplicationContext(this.contextLoader.initWebApplicationContext(getServletContext())); }}  

 

自己使用：

 

1.如果applicationContext文件是在src的根目录下：

  ApplicationContext apt= new FileSystemXmlApplicationContext("src/applicationContext.xml");

apt.getBean("ID");

可以取得

 

2.如果文件是在WebRoot/WEB-INF下可以用

ApplicationContext applicationContext= new FileSystemXmlApplicationContext("../applicationContext.xml");

取得

 

3.如果是在servlet中取可用

  ServletContext application = this.getServletContext();
  
  //获取spring上下文信息 为servlet使用
  WebApplicationContext wac = WebApplicationContextUtils.getWebApplicationContext(application);
  IDicService dicService = (IDicService)wac.getBean("dicService");