我如何在 spring 2.2.4.RELEASE 中从类中检索 jpa-repository 实例

Question

i need to retrieve specific instance of jpa-repository from an entity class to call findAll, findOne ecc...

Entity entity = getRepository(EntityClass).findOne(uriParamValue);

In the previous spring version (1.5.X) i was doing it this way:

public JpaRepository<Entity, Serializable> getRepository(Class<?> javaClass) {
    return (JpaRepository<Entity, Serializable>) repositories.getRepositoryFor(javaClass);
}

but in spring 2.2.X the Repository class interfaces has been changed from:

public Object getRepositoryFor(Class<?> domainClass) {

to:

public Optional<Object> getRepositoryFor(Class<?> domainClass) {

and i can't cast "Optional getRepositoryFor(X)" to JpaRepository instance to able to call JpaRepository methods.

Where am I doing wrong?

thanks

Answer 1

I'm not familiar with the getRepositoryFor method, but Optional is a standard Java class intruduced in Java SE 8. You can check if the value is present and get the actual value from the Optional if it is present. Here is a sample using orElseThrow , but there are also other variants. Checkout the Javadoc.

public JpaRepository<Entity, Serializable> getRepository(Class<?> javaClass) {
    return (JpaRepository<Entity, Serializable>) repositories.getRepositoryFor(javaClass)
           .orElseThrow(() -> new MyException());
}