java - 如何在 singleton jersey 拦截器中使用 RequestScoped 对象？

Question

Jersey 拦截器是在应用程序启动时构建的。因此，它的依赖项(在本例中为 Cipher )被注入(inject)到请求范围之外。

问题是密码是 stateful所以它们应该被注入(inject)到请求范围中。如何做到这一点？

@Provider
@Priority(Priorities.ENTITY_CODER + 1)
public class CryptInterceptor implements ReaderInterceptor, WriterInterceptor {

    @Inject @Named("ENC_CIPHER")
    private Cipher encryptionCipher;
    @Inject @Named("DEC_CIPHER")
    private Cipher decryptionCipher;

    @Override
    public Object aroundReadFrom(ReaderInterceptorContext context) throws IOException, WebApplicationException {
        InputStream inputStream = context.getInputStream();
        CipherInputStream cipherInputStream = new CipherInputStream(inputStream, decryptionCipher);
        context.setInputStream(cipherInputStream);
        return context.proceed();
    }

    @Override
    public void aroundWriteTo(WriterInterceptorContext context) throws IOException, WebApplicationException {
        OutputStream outputStream = context.getOutputStream();
        CipherOutputStream cipherOutputStream = new CipherOutputStream(outputStream, encryptionCipher);
        context.setOutputStream(cipherOutputStream);
        context.proceed();
    }
}

为每个新请求期待新的 Cipher 就像将它们注入(inject)到 RequestScope 中一样 --

public class BootstrapBinder extends AbstractBinder {
  @Override
  protected void configure() {
    bindFactory(EncCipherFactory.class).to(Cipher.class).named("ENC_CIPHER").in(RequestScoped.class);
    bindFactory(DecCipherFactory.class).to(Cipher.class).named("DEC_CIPHER").in(RequestScoped.class);
  }
}

现在显然 hk2( Jersey 的 DI)无法在 Singleton 拦截器内注入(inject) RequestScoped 对象。它导致:

java.lang.IllegalStateException: Not inside a request scope.

Answer 1

您需要代理服务。如果不这样做，Jersey 将尝试注入(inject)实际的对象，并且在创建拦截器时没有请求。至于试图使拦截器本身具有请求范围，我不知道。不确定是否可能。

bindFactory(EncCipherFactory.class)
        .proxy(true)
        .proxyForSameScope(false)
        .to(Cipher.class)
        .named("ENC_CIPHER")
        .in(RequestScoped.class);

对另一个也做同样的事情。但请记住，当您访问它时，它将是一个代理实例，而不是密码实例。

另请参阅:

• Request Scoped Injection into a Singleton