Java 在Jersey/hk2应用程序中配置EntityManager

我正试图在Jersey/Hk2应用程序中注入EntityManagerFactory（作为单例）和EntityManager（在请求范围内）

我用这个问题（）作为指导

我花了一天时间试着让它运行，但我遇到了很多异常。我不知道错误在哪里

WARNING: Unknown HK2 failure detected:
MultiException stack 1 of 3
org.glassfish.hk2.api.UnsatisfiedDependencyException: There was no object 
available for injection at SystemInjecteeImpl(requiredType=EntityManagerFactory,parent=EntityManagerProvider...)
...
While attempting to resolve the dependencies of mypackages.EntityManagerProvider errors were found
...
java.lang.IllegalStateException: Unable to perform operation: resolve on mypackages.EntityManagerProvider
...
There was no object available for injection at SystemInjecteeImpl(requiredType=EntityManagerFactory,parent=EntityManagerProvider...
...
java.lang.IllegalArgumentException: While attempting to resolve the dependencies of mypackages.EntityManagerProvider errors were found
...
java.lang.IllegalStateException: Unable to perform operation: resolve on mypackages.EntityManagerProvider

还有很多我删掉的例外

这是我的密码：

我的EntityManagerFactoryProvider（Singleton）：

MyApplicationBinder是：

 public class MyApplicationBinder extends AbstractBinder {

@Override
protected void configure() {
bindFactory(EntityManagerFactoryProvider.class)
   .to(EntityManagerFactory.class)
   .in(Singleton.class);
bindFactory(EntityManagerProvider.class)
   .to(EntityManager.class)
   .in(RequestScoped.class);
}
}

我的资源是：

@Path("myresource")
public class MyResource {

@Inject
EntityManager em;

/**
 * Method handling HTTP GET requests. The returned object will be sent
 * to the client as "text/plain" media type.
 *
 * @return String that will be returned as a text/plain response.
 */
@GET
@Produces(MediaType.TEXT_PLAIN)
public String getIt() {
    return "Got it!";
}

}

和Web.xml

<?xml version="1.0" encoding="UTF-8"?>
 <!-- This web.xml file is not required when using Servlet 3.0 container,
 see implementation details 
 http://jersey.java.net/nonav/documentation/latest/jax-rs.html -->
<web-app version="2.5" xmlns="http://java.sun.com/xml/ns/javaee" 
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 
xsi:schemaLocation="http://java.sun.com/xml/ns/javaee 
http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd">
<servlet>
    <servlet-name>MyApplication</servlet-name>
    <servlet-class>org.glassfish.jersey.servlet.ServletContainer</servlet-
    class>
    <init-param>
        <param-name>javax.ws.rs.Application</param-name>
        <param-value>mypackage.MyApplication</param-value>
    </init-param>
    <load-on-startup>1</load-on-startup>
</servlet>
<servlet-mapping>
    <servlet-name>MyApplication</servlet-name>
    <url-pattern>/webapi/*</url-pattern>
</servlet-mapping>
</web-app>

我的申请
org.glassfish.jersey.servlet.ServletContainer
javax.ws.rs.Application
mypackage.MyApplication
1.
我的申请
/webapi/*

---

非常感谢

我认为您没有显示完整的堆栈跟踪。在测试时，我确实看到了您在帖子中显示的跟踪的一部分，但它只是跟踪的一部分。主要原因是

java.lang.NoSuchMethodException:在EntityManagerFactoryProvider中找不到合适的构造函数

查看您的

EntityManagerFactoryProvider

构造函数

public EntityManagerFactoryProvider(@Named(PERSISTENT_UNIT) String persistentUnit) {
    emf = Persistence.createEntityManagerFactory(persistentUnit);
}

persistentUnit

应该来自哪里。你需要把它挂在活页夹里。而且，

@Named

没有定义注入点。它只是注射点的支持注释。当您

@Inject

时创建的注入点，就像您在

EntityManagerProvider

构造函数上所做的一样

public EntityManagerFactoryProvider(@Named(PERSISTENT_UNIT) String persistentUnit) {
    emf = Persistence.createEntityManagerFactory(persistentUnit);
}

因此，解决两件事：

绑定持久化单元名称

bind(persistenceUnitName).to(String.class).named(PERSISTENT_UNIT);

通过添加

@Inject

注释来创建注入点

@Inject
public EntityManagerFactoryProvider(@Named(PERSISTENT_UNIT) String persistentUnit) {
    emf = Persistence.createEntityManagerFactory(persistentUnit);
}

bind(persistenceUnitName).to(String.class).named(PERSISTENT_UNIT);

@Inject
public EntityManagerFactoryProvider(@Named(PERSISTENT_UNIT) String persistentUnit) {
    emf = Persistence.createEntityManagerFactory(persistentUnit);
}