JSF ManagedBean-注入的属性在STATE_SAVING_METHOD = client上无法正常工作 [英] JSF ManagedBean - injected properties not working correctly on STATE_SAVING_METHOD=client

问题描述

两天后我陷入困境，无法摆脱困境.

I am into a problem from two days and I can not get out from this.

反序列化后，我遇到的问题是使用MangedBean属性(我想).
该属性(purchaseManager)是通过Spring设置的，并使用DAO扩展了MyBatis作为数据映射器以与DB交互.
实际上，在第一次访问该页面时，init()方法中的purchaseManager.getAll()可以正常工作.
当我尝试通过按钮调用refreshList()作为操作时，在DAO中的getSqlSession()上出现了NullPointerException.

The problem I am having is using a MangedBean property after the deserialization (I guess).
The property (purchaseManager) is set up with Spring, and use a DAO which extends MyBatis as data mapper to interact with the DB.
In fact, on the first access to the page, purchaseManager.getAll() inside init() method works fine.
When i try to call refreshList() as an action from a button, I have a NullPointerException on the getSqlSession() inside the DAO.

仅留下相关代码的情况如下:

Letting only the relevant code the situation is as follow:

@ManagedBean(name = "purchaseController")
@ViewScoped
public class PurchaseController implements Serializable{

    @ManagedProperty(value = "#{purchaseManager}")
    private PurchaseManager purchaseManager;

    @PostConstruct
    public void init(){
        purchaseManager.getAll();
    }

    public void refreshList(){
        purchaseManager.getAll();
    }
}

public class PurchaseManagerImpl implements PurchaseManager, Serializable {
    PurchaseDAO purchaseDAO;

    public void getAll() {
        purchaseDAO.getAll()
    }
}

public class PurchaseDAOImpl extends SqlSessionDaoSupport implements PurchaseDAO, Serializable {

    public void getAll() {
        SqlSession session = getSqlSession();  // when the call comes from refreshList(), session is null
        session.selectList("PAYMENT.getAll", null);
    }
}

in web.xml
<context-param>
    <param-name>javax.faces.STATE_SAVING_METHOD</param-name>
    <param-value>server</param-value>
</context-param>

如果我将STATE_SAVING_METHOD更改为服务器，则应用程序可以正常运行，但不是我想要的.如果将ManageBean用作RequestScope也是一样，但这也会对我的要求造成不利影响.

If I change the STATE_SAVING_METHOD to server the application works fine but is not what I want. Same thing if I make the ManageBean as RequestScope but this too will penalize my requirements.

在此先感谢任何人的帮助！ Ermal

Thank you in advance to anyone for any kind of help! Ermal

推荐答案

解决了将<aop:scoped-proxy proxy-target-class="false" />添加到通过Spring声明的服务/管理器定义中的错误.这样就可以注入完全可序列化的代理实例.

Solved the error adding <aop:scoped-proxy proxy-target-class="false" /> to the definition of the service/manager declared through Spring. This makes possible the injection of a fully serializable proxy instance.

<bean id="purchaseManager" class="al.ozone.bl.manager.impl.PurchaseManagerImpl">    
    <property name="purchaseDAO" ref="purchaseDAO" />   
    <aop:scoped-proxy proxy-target-class="false" />
</bean> 

proxy-target-class="false"用于告诉PurchaseManagerImpl已经实现了一个接口.如果设置为true或省略，则必须使用CGLIB2库.

proxy-target-class="false" is for telling that PurchaseManagerImpl implements already an interface. If setted to true or omitted, CGLIB2 library must be used.

通过这种方式，JSF可以使用Spring + MyBatis正确地从数据库中获取数据.

In this way JSF is correctly taking data from DB using Spring+MyBatis.

关于这一点(对我而言)(更理论上)的迷雾是:

The mistery (for me) on this point (more theorical) is :

• 在幕后是否正确处理了MyBatis对象(PurchaseDAOImpl)和dataSource?
• 是否在每个HTTP请求上重新创建或还原了它们?

• Is MyBatis object (PurchaseDAOImpl) and the dataSource, correctly handled behind the scenes?
• Are they recreated or restored on each HTTP request?

请记住，我有STATE_SAVING_METHOD=client和BackingBean作为ViewScope.
我的目标是使服务器更轻巧，因为我希望有大量的用户交互.

Remember that I have STATE_SAVING_METHOD=client and BackingBean as ViewScope.
My Goal is to have the server lighter possible because I expect an hight number of user interactions.

<bean id="dataSource" class="org.apache.commons.dbcp.BasicDataSource"
    destroy-method="close">
    <property name="driverClassName" value="${jdbc.driverClassName}" />
    <property name="url" value="${jdbc.url}" />
    <property name="username" value="${jdbc.username}" />
    <property name="password" value="${jdbc.password}" />
    <property name="poolPreparedStatements" value="true" />
    <property name="defaultAutoCommit" value="false" />
</bean>

非常感谢任何人对此事有所启发！

Thank you very much to anyone for some light on this matter!

咨询链接:

Spring会话范围的bean (控制器)和对服务的引用(按照序列化方式

http ://static.springsource.org/spring/docs/2.5.x/reference/beans.html#beans-factory-scopes-other-injection

http://www.infoq.com/presentations/Whats -Spring-in-Spring-3.0

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