Updated JAXB parser configuration

Now JAXB response parser is activated by default if the Accept header is
set to application/xml or the method is annotated with the @JAXBResponseParser
annotation (this way we can still use it to parse documents with vendor-specific
mime-types).

This will not break current XML parsers, since they must be explicitly
defined with the @XMLResponseParser annotation, and will provide a
default XML parsing mechanism. The only requirement will be to have
domain objects annotated with standard Java JAXB annotations.

It would be great to refactor the @XMLResponseParser annotation to be
more flexible and to allow using other parsers than SAX, this way the
@JAXBResponseParser annotation could be removed. However, this change
may affect existing providers and must be studied with care.

core/src/main/java/org/jclouds/rest/internal/RestAnnotationProcessor.java

@@ -777,9 +777,7 @@ public class RestAnnotationProcessor<T> {
    public static Key<? extends Function<HttpResponse, ?>> getParserOrThrowException(Method method) {
       ResponseParser annotation = method.getAnnotation(ResponseParser.class);
       if (annotation == null) {
-         if (method.isAnnotationPresent(JAXBResponseParser.class)) {
+         if (method.getReturnType().equals(void.class)
-             return getJAXBParserKeyForMethod(method);
-         } else if (method.getReturnType().equals(void.class)
                || TypeLiteral.get(method.getGenericReturnType()).equals(futureVoidLiteral)) {
             return Key.get(ReleasePayloadAndReturn.class);
          } else if (method.getReturnType().equals(boolean.class) || method.getReturnType().equals(Boolean.class)
@@ -793,6 +791,9 @@ public class RestAnnotationProcessor<T> {
             return Key.get((Class) IdentityFunction.class);
          } else if (getAcceptHeadersOrNull(method).contains(MediaType.APPLICATION_JSON)) {
             return getJsonParserKeyForMethod(method);
+         } else if (getAcceptHeadersOrNull(method).contains(MediaType.APPLICATION_XML)
+                || method.isAnnotationPresent(JAXBResponseParser.class)) {
+            return getJAXBParserKeyForMethod(method);
          } else if (method.getReturnType().equals(String.class)
                || TypeLiteral.get(method.getGenericReturnType()).equals(futureStringLiteral)) {
             return Key.get(ReturnStringIf2xx.class);

core/src/test/java/org/jclouds/rest/internal/RestAnnotationProcessorTest.java

@@ -32,7 +32,6 @@ import static org.jclouds.io.Payloads.newStringPayload;
 import static org.jclouds.rest.RestContextFactory.contextSpec;
 import static org.jclouds.rest.RestContextFactory.createContextBuilder;
 import static org.testng.Assert.assertEquals;
-import static org.testng.Assert.assertNotNull;
 
 import java.io.File;
 import java.io.IOException;
@@ -2456,9 +2455,14 @@ public class RestAnnotationProcessorTest extends BaseRestClientTest {
    
    public interface TestJAXBResponseParser {
        @GET
-       @Path("/jaxb")
+       @Path("/jaxb/annotation")
        @JAXBResponseParser
-       public ListenableFuture<TestJAXBDomain> jaxbGet();
+       public ListenableFuture<TestJAXBDomain> jaxbGetWithAnnotation();
+       
+       @GET
+       @Path("/jaxb/header")
+       @Consumes(MediaType.APPLICATION_XML)
+       public ListenableFuture<TestJAXBDomain> jaxbGetWithAcceptHeader();
    }
    
    @XmlRootElement(name = "test")
@@ -2474,9 +2478,20 @@ public class RestAnnotationProcessorTest extends BaseRestClientTest {
    }
    
    @Test
-   public void testCreateJAXBResponseParser() throws SecurityException, NoSuchMethodException {
+   public void testCreateJAXBResponseParserWithAnnotation() throws SecurityException, NoSuchMethodException {
        RestAnnotationProcessor<TestJAXBResponseParser> processor = factory(TestJAXBResponseParser.class);
-       Method method = TestJAXBResponseParser.class.getMethod("jaxbGet");
+       Method method = TestJAXBResponseParser.class.getMethod("jaxbGetWithAnnotation");
+       GeneratedHttpRequest<TestJAXBResponseParser> request = GeneratedHttpRequest.<TestJAXBResponseParser> builder().method("GET")
+                .endpoint(URI.create("http://localhost")).declaring(TestJAXBResponseParser.class).javaMethod(method).args(
+                         new Object[] {}).build();
+       Function<HttpResponse, ?> transformer = processor.createResponseParser(method, request);
+       assertEquals(transformer.getClass(), ParseXMLWithJAXB.class);
+    }
+   
+   @Test
+   public void testCreateJAXBResponseParserWithAcceptHeader() throws SecurityException, NoSuchMethodException {
+       RestAnnotationProcessor<TestJAXBResponseParser> processor = factory(TestJAXBResponseParser.class);
+       Method method = TestJAXBResponseParser.class.getMethod("jaxbGetWithAcceptHeader");
        GeneratedHttpRequest<TestJAXBResponseParser> request = GeneratedHttpRequest.<TestJAXBResponseParser> builder().method("GET")
                 .endpoint(URI.create("http://localhost")).declaring(TestJAXBResponseParser.class).javaMethod(method).args(
                          new Object[] {}).build();
@@ -2486,8 +2501,26 @@ public class RestAnnotationProcessorTest extends BaseRestClientTest {
    
    @SuppressWarnings("unchecked")
    @Test
-   public void testJAXBResponseParser() throws SecurityException, NoSuchMethodException, IOException {
+   public void testJAXBResponseParserWithAnnotation() throws SecurityException, NoSuchMethodException, IOException {
-       Method method = TestJAXBResponseParser.class.getMethod("jaxbGet");
+       Method method = TestJAXBResponseParser.class.getMethod("jaxbGetWithAnnotation");
+       HttpRequest request = factory(TestJAXBResponseParser.class).createRequest(method);
+
+       assertResponseParserClassEquals(method, request, ParseXMLWithJAXB.class);
+       // now test that it works!
+
+       Function<HttpResponse, TestJAXBDomain> parser = (Function<HttpResponse, TestJAXBDomain>) RestAnnotationProcessor
+                .createResponseParser(parserFactory, injector, method, request);
+       
+       StringBuffer payload = new StringBuffer("<?xml version=\"1.0\" encoding=\"UTF-8\" standalone=\"yes\"?>");
+       payload.append("<test><elem>Hello World</elem></test>");
+       TestJAXBDomain domain = parser.apply(new HttpResponse(200, "ok", newStringPayload(payload.toString())));
+       assertEquals(domain.getElem(), "Hello World");
+    }
+   
+   @SuppressWarnings("unchecked")
+   @Test
+   public void testJAXBResponseParserWithAcceptHeader() throws SecurityException, NoSuchMethodException, IOException {
+       Method method = TestJAXBResponseParser.class.getMethod("jaxbGetWithAcceptHeader");
        HttpRequest request = factory(TestJAXBResponseParser.class).createRequest(method);
 
        assertResponseParserClassEquals(method, request, ParseXMLWithJAXB.class);