编写 Native 应用程序的技巧

    public class Person {
        private String first;
        private String last;

        public String getFirst() {
            return first;
        }

        public void setFirst(String first) {
            this.first = first;
        }

        public String getLast() {
            return last;
        }

        public void setValue(String last) {
            this.last = last;
        }
    }

    @Path("/person")
    @Produces(MediaType.APPLICATION_JSON)
    @Consumes(MediaType.APPLICATION_JSON)
    public class PersonResource {

        private final Jsonb jsonb;

        public PersonResource() {
            jsonb = JsonbBuilder.create(new JsonbConfig());
        }

        @GET
        public Response list() {
            return Response.ok(jsonb.fromJson("{\"first\":  \"foo\", \"last\":  \"bar\"}", Person.class)).build();
        }
    }

Exception handling request to /person: org.jboss.resteasy.spi.UnhandledException: jakarta.json.bind.JsonbException: Can't create instance of a class: class org.acme.jsonb.Person, No default constructor found

com.fasterxml.jackson.databind.exc.InvalidDefinitionException: No serializer found for class org.acme.jsonb.Person and no properties discovered to create BeanSerializer (to avoid exception, disable SerializationFeature.FAIL_ON_EMPTY_BEANS)

@RegisterForProxy
public interface MyInterface extends MySecondInterface {
}

@RegisterForProxy(targets={MyInterface.class, MySecondInterface.class})
public class MyReflectionConfiguration {
}

Error: No instances are allowed in the image heap for a class that is initialized or reinitialized at image runtime: sun.security.provider.NativePRNG
Trace: object java.security.SecureRandom
method com.amazonaws.services.s3.model.CryptoConfiguration.<init>(CryptoMode)
Call path from entry point to com.amazonaws.services.s3.model.CryptoConfiguration.<init>(CryptoMode):

Error: com.oracle.graal.pointsto.constraints.UnsupportedFeatureException: Detected an instance of Random/SplittableRandom class in the image heap. Instances created during image generation have cached seed values and don't behave as expected.

com.oracle.svm.core.jdk.UnsupportedFeatureError: Proxy class defined by interfaces [interface org.apache.http.conn.HttpClientConnectionManager, interface org.apache.http.pool.ConnPoolControl, interface com.amazonaws.http.conn.Wrapped] not found. Generating proxy classes at runtime is not supported. Proxy classes need to be defined at image build time by specifying the list of interfaces that they implement. To define proxy classes use -H:DynamicProxyConfigurationFiles=<comma-separated-config-files> and -H:DynamicProxyConfigurationResources=<comma-separated-config-resources> options.

@Path("/singletons")
public class Singletons {

    @GET
    @Path("/static")
    public long withStatic() {
        return StaticSingleton.startTime();
    }
}

class StaticSingleton {
    static final long START_TIME = System.currentTimeMillis();

    static long startTime() {
        return START_TIME;
    }
}

$ curl https://:8080/singletons/static
1656509254532%

$ curl https://:8080/singletons/static
1656509254532%

### Restart the native application ###

$ curl https://:8080/singletons/static
1656509254532%

@Path("/singletons")
public class Singletons {

    @GET
    @Path("/enum")
    public long withEnum() {
        return EnumSingleton.INSTANCE.startTime();
    }
}

enum EnumSingleton {
    INSTANCE(System.currentTimeMillis());

    private final long startTime;

    private EnumSingleton(long startTime) {
        this.startTime = startTime;
    }

    long startTime() {
        return startTime;
    }
}

$ curl https://:8080/singletons/enum
1656509254601%

$ curl https://:8080/singletons/enum
1656509254601%

### Restart the native application ###

$ curl https://:8080/singletons/enum
1656509254601%

@Path("/singletons")
public class Singletons {

    @Inject
    CdiSingleton cdiSingleton;

    @GET
    @Path("/cdi")
    public long withCdi() {
        return cdiSingleton.startTime();
    }
}

@Singleton
class CdiSingleton {
    // Note that the field is not static
    final long startTime = System.currentTimeMillis();

    long startTime() {
        return startTime;
    }
}

$ curl https://:8080/singletons/cdi
1656510218554%

$ curl https://:8080/singletons/cdi
1656510218554%

### Restart the native application ###

$ curl https://:8080/singletons/cdi
1656510714689%

public class SaxParserProcessor {

    @BuildStep
    ReflectiveClassBuildItem reflection() {
        // since we only need reflection to the constructor of the class, we can specify `false` for both the methods and the fields arguments.
        return new ReflectiveClassBuildItem(false, false, "com.sun.org.apache.xerces.internal.parsers.SAXParser");
    }

}

public class ResourcesProcessor {

    @BuildStep
    NativeImageResourceBuildItem nativeImageResourceBuildItem() {
        return new NativeImageResourceBuildItem("META-INF/extra.properties");
    }

}

public class S3Processor {

    @BuildStep
    RuntimeInitializedClassBuildItem cryptoConfiguration() {
        return new RuntimeInitializedClassBuildItem(CryptoConfiguration.class.getCanonicalName());
    }

}

public class S3Processor {

    @BuildStep
    NativeImageProxyDefinitionBuildItem httpProxies() {
        return new NativeImageProxyDefinitionBuildItem("org.apache.http.conn.HttpClientConnectionManager",
                "org.apache.http.pool.ConnPoolControl", "com.amazonaws.http.conn.Wrapped");
    }

}