Java_web开发_SSH spring中取得Bean实例的方法 .

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

 

[java] view plaincopyprint?

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");  
    }           
}  
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

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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);  
    }  
}

• 
  

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:

 

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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;  
    }  
}

• 
  

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
 

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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);  
  }  
}

• 
  

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?

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;  
    }  
}

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.

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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()));  
    }  
}

• 
  

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");

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