@Inject无状态EJB包含来自先前请求的数据 [英] @Inject stateless EJB contains data from previous request

问题描述

我有一个JAX-RS webservice，其中包含一个生成测试数据的资源。在测试期间，我发现注入的EJB没有重新初始化，并且仍然包含最后一个请求的数据。

我有一个包含EJB的业务逻辑的jar文件 server.jar 为了显示我的问题，我创建了一个无状态的bean：

  @Stateless 
 public class TestService 
 {
 @EJB 
 SubsequentTestService state2Service; 
 
 private String value; 
 
 public void testIt（）
 {
 System.out.println（###### VALUE：+ value）; 
 value =TestValue; 
 
 state2Service.testIt（）; 
} 
} 
  

我正在使用后续调用 SubsequentTestService 显示另一个无状态EJB调用的奇怪行为：

  @Stateless 
 public class SubsequentTestService 
 {
 private String value; 
 
 public void testIt（）
 {
 System.out.println（###### VALUE2：+ value）; 
 value =TestValue2; 
} 
} 
  

更改注释表单 @ EJB 到 @Inject 不会更改任何内容。

我的 web.war 我有简单的JAX-RS bean。被称为显示奇怪行为的定义如下：

  @Path（/ test）
 public class TestResource 
 {
 @Inject 
 TestService testService; 
 
 @GET 
 @Path（/ state）
 public void testState（）
 {
 testService.testIt（）; 
} 
} 
  

JAX-RS应用程序配置如下所示： / p>

  @ApplicationPath（/ api）
 public class JaxRsConfiguration extends Application 
 {
} 
  

war文件包含beans.xml，但没有其他配置文件。一切都被打包成一个ear文件，并部署在wildfly 10.0.0.Final中。如果我通过 http：// localhost：8080 / api / test / state 我得到预期的输出：

INFO [stdout]（默认任务-7）####### VALUE：null < br>
INFO [stdout]（默认任务-7）####### VALUE2：null

但是在第二个请求中，我收到以下意外的输出：

INFO [stdout]（默认任务-8）####### VALUE ：TestValue

INFO [stdout]（默认任务-8）####### VALUE2：TestValue2

这里有什么问题？在野鸭中可能会配置错误吗？但是我只是改变了日志和数据源的定义。

解决方案

你的意思是 @Stateless 向后。

这并不是这样的：

嘿，容器，这是一个任意的类，请使它成为一个无状态的bean。

意思就是这样：

嘿容器，这里是一个无状态的类，你可以安全地使用它作为无状态的bean。 >

你有一个有状态的类。您应该将其标记为 @Stateful bean。否则，摆脱所有状态（非托管实例变量），以便您可以安全地将其用作 @Stateless bean。

另见：

• 为什么是无状态会话bean？



li> 使用@EJB时，每个托管bean是否都有自己的@EJB实例？

I have a JAX-RS webservice with a resource for generating testdata. During tests I found out, that the injected EJB is not reinitialized and still contains data from the last request.

I have a jar file server.jar containing my business logic with EJBs. To show my problem I have created a stateless bean:

@Stateless
public class TestService
{
    @EJB
    SubsequentTestService state2Service;

    private String value;

    public void testIt()
    {
        System.out.println("####### VALUE: " + value);
        value = "TestValue";

        state2Service.testIt();
    }
}

I am using the subsequent call to SubsequentTestService to show the odd behaviour also exists for call of another stateless EJB:

@Stateless
public class SubsequentTestService
{
    private String value;

    public void testIt()
    {
        System.out.println("####### VALUE2: " + value);
        value = "TestValue2";
    }
}

Changing the annotation form @EJB to @Inject does not change anything.

In my web.war I have simple JAX-RS beans. The one which is called to show the strange behaviour is defined as follows:

@Path("/test")
public class TestResource
{
    @Inject
    TestService testService;

    @GET
    @Path("/state")
    public void testState()
    {
        testService.testIt();
    }
}

The JAX-RS application configuration looks as follows:

@ApplicationPath("/api")
public class JaxRsConfiguration extends Application
{
}

The war file contains the beans.xml, but no other configuration file. Everything is packaged into an ear file and is deployed in wildfly 10.0.0.Final. If I call the webservice as GET request via http://localhost:8080/api/test/state I get the expected output:

INFO [stdout] (default task-7) ####### VALUE: null
INFO [stdout] (default task-7) ####### VALUE2: null

But on the second request I get following unexpected output:

INFO [stdout] (default task-8) ####### VALUE: TestValue
INFO [stdout] (default task-8) ####### VALUE2: TestValue2

What is my problem here? Might be anything misconfigured in the wildfly? But I have only changed the logging and the datasource definition.

解决方案

You have the meaning of @Stateless backwards.

This does not mean like so:

Hey container, here's an arbitrary class, please make it a stateless bean.

This actually means like so:

Hey container, here's a stateless class, you can safely use it as a stateless bean.

You have a stateful class. You should mark it as a @Stateful bean. Otherwise, get rid of all the state (unmanaged instance variables) so you can safely use it as a @Stateless bean.

See also:

• Why Stateless session beans?
• JSF request scoped bean keeps recreating new Stateful session beans on every request?
• When using @EJB, does each managed bean get its own @EJB instance?

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