如何從一個類中獲取會話對象？

Question

有一類：

HttpServletRequest request = ((ServletRequestAttributes)RequestContextHolder.getRequestAttributes()).getRequest(); 

那麼，有沒有辦法讓session（HttpSession中）對象：

@Configuration 
@ComponentScan("com.ambre.pta") 
@EnableTransactionManagement 
@PropertySources({ 
    @PropertySource("classpath:fr/global.properties"), 
    @PropertySource("classpath:fr/main.properties"), 
    @PropertySource("classpath:fr/admin.properties"), 
    @PropertySource("classpath:fr/referentiel.properties"), 
    @PropertySource("classpath:fr/departement.properties"), 
    @PropertySource("classpath:fr/exercice.properties"), 
    @PropertySource("classpath:fr/defi.properties") 
}) 
public class ApplicationContextConfig { 

    @Bean 
    public static PropertySourcesPlaceholderConfigurer properties() { 
     return new PropertySourcesPlaceholderConfigurer(); 
    } 

    @Bean(name = "viewResolver") 
    public InternalResourceViewResolver getViewResolver() { 
     InternalResourceViewResolver viewResolver = new InternalResourceViewResolver(); 
     viewResolver.setPrefix("/WEB-INF/views/"); 
     viewResolver.setSuffix(".jsp"); 
     return viewResolver; 
    } 

    @Bean(name = "dataSource") 
    public DataSource getDataSource() { 

     BasicDataSource bds = new BasicDataSource(); 

     bds.setDriverClassName("oracle.jdbc.driver.OracleDriver"); 
     bds.setUrl("jdbc:oracle:thin:@localhost:1521:xe"); 

     bds.setUsername("pta"); 
     bds.setPassword("pta"); 

     return bds; 

    } 

    @Autowired 
    @Bean(name = "sessionFactory") 
    public SessionFactory getSessionFactory(DataSource dataSource) { 

     LocalSessionFactoryBuilder sessionBuilder = new LocalSessionFactoryBuilder(dataSource); 

     sessionBuilder.scanPackages("com.ambre.pta.model"); 

     return sessionBuilder.buildSessionFactory(); 

    } 

    @Autowired 
    @Bean(name = "transactionManager") 
    public HibernateTransactionManager getTransactionManager(SessionFactory sessionFactory) { 

     HibernateTransactionManager transactionManager = new HibernateTransactionManager(sessionFactory); 

     return transactionManager; 

    } 

    @Autowired 
    @Bean(name = "utilisateurDao") 
    public UtilisateurDAO getUtilisateurDao(SessionFactory sessionFactory) { 
     return new UtilisateurDAOImpl(sessionFactory); 
    } 

} 

我們可以通過這種方式得到這個類中request對象？

Answer 1

使用控制器類

您可以定義HttpSession作爲參數傳遞給你的控制器方法：

@RequestMapping("/my-path") 
public String doStuff(HttpSession session) { 
    // do stuff... 
} 

這也是訪問HttpRequest，而不是通過RequestContextHolder要推薦的方式，因爲它更容易模擬出測試的會話。

見the Spring MVC docs for more detail.

不使用控制器類

另一種選擇是使用@SessionScope豆，並相應地發生變異它：

@Component 
@SessionScope 
public class MySessionScopedBean { 
    String attribute; 
} 

public class MyOtherClass { 
    @Autowired 
    private MySessionScopedBean myBean; 

    public void doStuff() { 
     // myBean accesses a bean instance isolated in the user session 
     myBean.attribute = "test"; 
    } 

} 

Answer 2

如果你想訪問一個控制器方法外HttpSession中，有兩個可能的答案：

1. 不要這樣做，它是邪惡的。

2. 如果你真的想這樣做（我已經做了，在過去，所以我是誰怪你），那麼最簡單的方法是寫一個類來保存會話，並攔截設置並取消它。但是，爲了方便起見，我將用HttpServletRequest的對象時，您可以從中提取會話：「如何從類中獲取一般會話對象」

   public class RequestHolder { 
   
       private static final ThreadLocal<HttpServletRequest> REQUEST = 
             new ThreadLocal<>(); 
   
       public static HttpServletRequest getCurrentRequest() { 
        return REQUEST.get(); 
       } 
   
       public static HttpSession getCurrentSession() { 
        HttpServletRequest request = REQUEST.get(); 
        return request == null ? null : request.getSession(); 
       } 
   
       public static void setCurrentRequest(HttpServletRequest request) { 
        REQUEST.set(request); 
       } 
   
       public static void unsetCurrentRequest() { 
        REQUEST.remove(); 
       } 
   
   } 
   
   public class RequestHolderInterceptor implements HandlerInterceptor { 
       @Override 
       public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object o) { 
        RequestHolder.setCurrentRequest(request); 
        return true; 
       } 
   
       @Override 
       public void postHandle(HttpServletRequest request, HttpServletResponse response, Object o, ModelAndView mav) { 
       } 
   
       @Override 
       public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object o, Exception e){ 
        RequestHolder.unsetCurrentRequest(); 
       } 
   }