#13 - Introduced LinkBuilder implementation inspecting JAX-RS @Path annotation.

Refactored LinkBuilder(Factory) classes to extract reusable code into common superclass for ControllerLinkBuilder and JaxRsLinkBuilder.

src/main/java/org/springframework/hateoas/jaxrs/JaxRsLinkBuilder.java

@@ -0,0 +1,90 @@
+/*
+ * Copyright 2012 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.springframework.hateoas.jaxrs;
+
+import javax.ws.rs.Path;
+
+import org.springframework.core.annotation.AnnotationUtils;
+import org.springframework.hateoas.LinkBuilder;
+import org.springframework.hateoas.mvc.UriComponentsLinkBuilder;
+import org.springframework.web.servlet.support.ServletUriComponentsBuilder;
+import org.springframework.web.util.UriComponentsBuilder;
+import org.springframework.web.util.UriTemplate;
+
+/**
+ * {@link LinkBuilder} to derive URI mappings from a JAX-RS {@link Path} annotation.
+ * 
+ * @author Oliver Gierke
+ */
+public class JaxRsLinkBuilder extends UriComponentsLinkBuilder<JaxRsLinkBuilder> {
+
+	/**
+	 * Creates a new {@link JaxRsLinkBuilder} from the given {@link UriComponentsBuilder}.
+	 * 
+	 * @param builder must not be {@literal null}.
+	 */
+	private JaxRsLinkBuilder(UriComponentsBuilder builder) {
+		super(builder);
+	}
+
+	/**
+	 * Creates a {@link JaxRsLinkBuilder} instance to link to the {@link Path} mapping tied to the given class.
+	 * 
+	 * @param service the class to discover the annotation on, must not be {@literal null}.
+	 * @return
+	 */
+	public static JaxRsLinkBuilder linkTo(Class<?> service) {
+		return linkTo(service, new Object[0]);
+	}
+
+	/**
+	 * Creates a new {@link JaxRsLinkBuilder} instance to link to the {@link Path} mapping tied to the given class binding
+	 * the given parameters to the URI template.
+	 * 
+	 * @param service the class to discover the annotation on, must not be {@literal null}.
+	 * @param parameters additional parameters to bind to the URI template declared in the annotation, must not be
+	 *          {@literal null}.
+	 * @return
+	 */
+	public static JaxRsLinkBuilder linkTo(Class<?> service, Object... parameters) {
+
+		Path annotation = AnnotationUtils.findAnnotation(service, Path.class);
+		String path = (String) AnnotationUtils.getValue(annotation);
+
+		JaxRsLinkBuilder builder = new JaxRsLinkBuilder(ServletUriComponentsBuilder.fromCurrentServletMapping());
+
+		UriTemplate template = new UriTemplate(path);
+		return builder.slash(template.expand(parameters));
+	}
+
+	/* 
+	 * (non-Javadoc)
+	 * @see org.springframework.hateoas.UriComponentsLinkBuilder#getThis()
+	 */
+	@Override
+	protected JaxRsLinkBuilder getThis() {
+		return this;
+	}
+
+	/* 
+	 * (non-Javadoc)
+	 * @see org.springframework.hateoas.UriComponentsLinkBuilder#createNewInstance(org.springframework.web.util.UriComponentsBuilder)
+	 */
+	@Override
+	protected JaxRsLinkBuilder createNewInstance(UriComponentsBuilder builder) {
+		return new JaxRsLinkBuilder(builder);
+	}
+}

src/main/java/org/springframework/hateoas/jaxrs/JaxRsLinkBuilderFactory.java

@@ -0,0 +1,45 @@
+/*
+ * Copyright 2012 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.springframework.hateoas.jaxrs;
+
+import org.springframework.hateoas.LinkBuilder;
+import org.springframework.hateoas.LinkBuilderFactory;
+
+/**
+ * Factory for {@link LinkBuilder} instances based on the path mapping annotated on the given JAX-RS service.
+ * 
+ * @author Ricardo Gladwell
+ * @author Oliver Gierke
+ */
+public class JaxRsLinkBuilderFactory implements LinkBuilderFactory<JaxRsLinkBuilder> {
+
+	/*
+	 * (non-Javadoc)
+	 * @see org.springframework.hateoas.LinkBuilderFactory#linkTo(java.lang.Class)
+	 */
+	public JaxRsLinkBuilder linkTo(Class<?> service) {
+		return JaxRsLinkBuilder.linkTo(service);
+	}
+
+	/*
+	 * (non-Javadoc)
+	 * @see org.springframework.hateoas.LinkBuilderFactory#linkTo(java.lang.Class, java.lang.Object[])
+	 */
+	@Override
+	public JaxRsLinkBuilder linkTo(Class<?> service, Object... parameters) {
+		return JaxRsLinkBuilder.linkTo(service, parameters);
+	}
+}