问题描述
有关的跟进。我正在尝试使用JSR-330标准注释注册应用程序配置数据，并使用与泽西搭配的HK2框架。
Kind of a follow up to my previous question. I'm trying to inject application configuration data using JSR-330 standard annotations and the HK2 framework bundled with jersey.
理想情况下，我想为命名为 InjectionResolver c $ c>注释，它将在我将从数据中填充的 Map 或属性对象中查找所需的值在别处阅读在我第一次尝试中，我创建了一个应用程序实例，如
Ideally I'd like to create a custom InjectionResolver for the Named annotation, which will lookup the desired values in a Map or Properties object that I will populate from data read elsewhere. In my first attempt I've created an Application instance like
public class MyApplication extends ResourceConfig {
...
packages(MY_PACKAGES);
property(MY_CONFIG_PROPERTY, someValue);
register(new AbstractBinder() {
@Override
protected void configure() {
bind(ConfigurationInjectionResolver.class)
.to(new TypeLiteral<InjectionResolver<Named>>(){})
.in(Singleton.class)
}
});
}
然后我的 InjectionResolver 看起来像
public class ConfigurationInjectionResolver implements InjectionResolver<Named> {
@Context Application application;
@Override
public Object resolve(Injectee injectee, ServiceHandle<?> serviceHandle) {
// lookup data in application.getProperties();
}
}
我的问题是应用程序.getProperties（）为空。任何想法怎么了？另外，我可以绑定一个Injector的实例，而不是绑定该类吗？这样我可以构造一个传递我的 Map 数据作为参数的实例。
My problem is that application.getProperties() is empty. Any idea what's wrong? Also, could I bind an instance of my Injector instead of binding the class? That way I could construct the instance passing my Map data as a parameter.
推荐答案
不，这实际上对我来说完全正常。
No. This actually works perfectly fine for me.
public class ConfigurationInjectionResolver implements InjectionResolver<Named> {
@Context
Application application;
@Override
public Object resolve(Injectee injectee, ServiceHandle<?> root) {
Named annotation = injectee.getParent().getAnnotation(Named.class);
Map<String, Object> props = application.getProperties();
String name = annotation.value();
System.out.println(props.get(name));
return props.get(name);
}
@Override
public boolean isConstructorParameterIndicator() { return false; }
@Override
public boolean isMethodParameterIndicator() { return false; }
}
@ApplicationPath("/rest")
public class JerseyApplication extends ResourceConfig {
public JerseyApplication() {
packages("jersey.startup.test");
property("hello.config", "Hello World Property");
register(new AbstractBinder() {
@Override
protected void configure() {
bind(ConfigurationInjectionResolver.class)
.to(new TypeLiteral<InjectionResolver<Named>>() {
}).in(Singleton.class);
}
});
}
}
资源
@Path("/config")
public class ConfigResource {
@Named("hello.config")
String hello;
@GET
public Response getHello() {
return Response.ok(hello).build();
}
}
个人而言，在这种情况下，我将创建自己的注释，以免覆盖 @Named 注释。
Personally though, in this situation, I would create my own annotation, as to not override any existing functionality of the @Named annotation.
HK2有一个配置扩展，您可以在其中从 .properties 属性对象c $ c>文件，并使这些属性自动注入 @Configured 注释。我找不到任何文档，但在。
HK2 has a configuration extension, where you can load a Properties object from say a .properties file and and have those properties automatically injected with the @Configured annotation. I couldn't find any documentation on this, but there is an example usage of it in the HK2 source code examples.
这是一个示例实现
必需的依赖关系。检查泽西版本，看看它取决于什么HK2版本。在我的情况下，泽西2.13使用HK2 2.3.0-b10，所以应该是 $ {hk2.version}
Required dependencies. Check the Jersey version and see what HK2 version it depends on. In my case Jersey 2.13 uses HK2 2.3.0-b10, so that should be the ${hk2.version}
<dependency>
<groupId>org.glassfish.hk2</groupId>
<artifactId>hk2-configuration-hub</artifactId>
<version>${hk2.version}</version>
</dependency>
<dependency>
<groupId>org.glassfish.hk2</groupId>
<artifactId>hk2-configuration-integration</artifactId>
<version>${hk2.version}</version>
</dependency>
<dependency>
<groupId>org.glassfish.hk2</groupId>
<artifactId>hk2-property-file</artifactId>
<version>${hk2.version}</version>
</dependency>
App config
App config
@ApplicationPath("/rest")
public class JerseyApplication extends ResourceConfig {
@Inject
public JerseyApplication(ServiceLocator locator) {
packages("jersey.startup.test");
ServiceLocatorUtilities.addClasses(locator, ConfigResource.class);
try {
loadConfigurationProperties(locator);
} catch (IOException ex) {
Logger.getLogger(JerseyApplication.class.getName())
.log(Level.SEVERE, null, ex);
}
}
private void loadConfigurationProperties(ServiceLocator locator)
throws IOException {
ConfigurationUtilities.enableConfigurationSystem(locator);
PropertyFileUtilities.enablePropertyFileService(locator);
PropertyFileService propertyFileService
= locator.getService(PropertyFileService.class);
Properties props = new Properties();
URL url = getClass().getResource("/configuration.properties");
props.load(url.openStream());
PropertyFileHandle propertyFileHandle
= propertyFileService.createPropertyHandleOfAnyType();
propertyFileHandle.readProperties(props);
}
}
configuration.properties
configuration.properties
AppConfiguration.App.hello=Hello Squirrel Property!
资源
@Path("/config")
@ConfiguredBy("AppConfiguration")
public class ConfigResource {
@Configured
String hello;
@GET
public Response getHello() {
return Response.ok(hello).build();
}
}
Diclaimer：由于此功能没有很好的记录，我不知道我在这里有很好的实现。这只是试错。例如这个
Diclaimer: Since this feature isn't well documented, I am not sure if I have a good implementation here. It is just by trial and error. For instance this
ServiceLocatorUtilities.addClasses(locator, ConfigResource.class);
我觉得不必要。看起来很多，因为我已经是打包扫描。所以要明确添加 ConfigResource 到定位器上下文对我来说似乎不对。
I feel shouldn't be necessary. It seems redundant, as I am already package scanning. So to explicitly add the ConfigResource to the locator context doesn't seem right to me.
这篇关于使用自定义的hk2 InjectionResolver来注入应用程序配置的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持！