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Jersey - Inject configuration properties into constructor
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import org.glassfish.hk2.api.Injectee; | |
import org.glassfish.hk2.api.InjectionResolver; | |
import org.glassfish.hk2.api.ServiceHandle; | |
import org.glassfish.hk2.api.TypeLiteral; | |
import org.glassfish.hk2.utilities.binding.AbstractBinder; | |
import org.glassfish.jersey.filter.LoggingFilter; | |
import org.glassfish.jersey.server.ResourceConfig; | |
import org.glassfish.jersey.test.JerseyTest; | |
import org.junit.Test; | |
import javax.inject.Inject; | |
import javax.inject.Singleton; | |
import javax.ws.rs.GET; | |
import javax.ws.rs.Path; | |
import javax.ws.rs.core.Response; | |
import java.lang.annotation.*; | |
import java.lang.reflect.AnnotatedElement; | |
import java.lang.reflect.Constructor; | |
import java.util.HashMap; | |
import java.util.Map; | |
import java.util.logging.Logger; | |
import static org.junit.Assert.*; | |
/** | |
* Run like any other JUnit Test. Only on required dependency | |
* | |
* <dependency> | |
* <groupId>org.glassfish.jersey.test-framework.providers</groupId> | |
* <artifactId>jersey-test-framework-provider-grizzly2</artifactId> | |
* <version>${jersey2.version}</version> | |
* </dependency> | |
* | |
* @author Paul Samsotha | |
*/ | |
public class ConfigExample extends JerseyTest { | |
@Target({ElementType.FIELD, ElementType.PARAMETER}) | |
@Retention(RetentionPolicy.RUNTIME) | |
public static @interface Config { | |
String value(); | |
} | |
public static class ConfigInjectionResolver implements InjectionResolver<Config> { | |
private static final Map<String, String> properties = new HashMap<>(); | |
public ConfigInjectionResolver() { | |
properties.put("greeting.message", "Hello World"); | |
} | |
@Override | |
public Object resolve(Injectee injectee, ServiceHandle<?> handle) { | |
if (String.class == injectee.getRequiredType()) { | |
AnnotatedElement elem = injectee.getParent(); | |
if (elem instanceof Constructor) { | |
Constructor ctor = (Constructor) elem; | |
Config config = (Config) ctor.getParameterAnnotations()[injectee.getPosition()][0]; | |
return properties.get(config.value()); | |
} else { | |
Config config = elem.getAnnotation(Config.class); | |
return properties.get(config.value()); | |
} | |
} | |
return null; | |
} | |
@Override | |
public boolean isConstructorParameterIndicator() { return true; } | |
@Override | |
public boolean isMethodParameterIndicator() { return false; } | |
} | |
private static interface GreetingService { | |
String getGreeting(); | |
} | |
private static class ConfiguredGreetingService implements GreetingService { | |
private String message; | |
public ConfiguredGreetingService(@Config("greeting.message") String message) { | |
this.message = message; | |
} | |
@Override | |
public String getGreeting() { | |
return this.message; | |
} | |
} | |
@Path("greeting") | |
public static class GreetingResource { | |
@Inject | |
private GreetingService greetingService; | |
@GET | |
public String getConfigProp() { | |
return greetingService.getGreeting(); | |
} | |
} | |
@Override | |
public ResourceConfig configure() { | |
ResourceConfig config = new ResourceConfig(GreetingResource.class); | |
config.register(new LoggingFilter(Logger.getAnonymousLogger(), true)); | |
config.register(new AbstractBinder(){ | |
@Override | |
protected void configure() { | |
bind(ConfiguredGreetingService.class).to(GreetingService.class).in(Singleton.class); | |
bind(ConfigInjectionResolver.class) | |
.to(new TypeLiteral<InjectionResolver<Config>>(){}) | |
.in(Singleton.class); | |
} | |
}); | |
return config; | |
} | |
@Test | |
public void should_get_configured_greeting() { | |
final Response response = target("greeting") | |
.request().get(); | |
assertEquals("Hello World", response.readEntity(String.class)); | |
} | |
} |
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