added LazyLoadingProxy.isResolved() (DE-805, #271)

Author: rashtao

src/main/java/com/arangodb/springframework/core/convert/resolver/AbstractResolver.java

@@ -45,11 +45,13 @@ public abstract class AbstractResolver<A extends Annotation> {
 
 	private static final Method GET_ENTITY_METHOD;
 	private static final Method GET_REF_ID_METHOD;
+	private static final Method IS_RESOLVED;
 
 	static {
 		try {
 			GET_ENTITY_METHOD = LazyLoadingProxy.class.getMethod("getEntity");
 			GET_REF_ID_METHOD = LazyLoadingProxy.class.getMethod("getRefId");
+			IS_RESOLVED = LazyLoadingProxy.class.getMethod("isResolved");
 		} catch (final Exception e) {
 			throw new RuntimeException(e);
 		}
@@ -140,6 +142,11 @@ public Object intercept(final Object obj, final Method method, final Object[] ar
 			if (GET_REF_ID_METHOD.equals(method)) {
 				return id;
 			}
+
+			if (IS_RESOLVED.equals(method)) {
+				return resolved;
+			}
+
 			if (method.getName().equals("canEqual")) {
 				return proxyCanEqual(ensureResolved(), args[0]);
 			}

src/main/java/com/arangodb/springframework/core/convert/resolver/LazyLoadingProxy.java

@@ -41,4 +41,9 @@ public interface LazyLoadingProxy {
 	 */
 	String getRefId();
 
+	/**
+	 * @return whether the proxy is resolved
+	 */
+	boolean isResolved();
+
 }

src/test/java/com/arangodb/springframework/core/mapping/LazyLoadingProxyTest.java

@@ -0,0 +1,56 @@
+/*
+ * DISCLAIMER
+ *
+ * Copyright 2018 ArangoDB GmbH, Cologne, Germany
+ *
+ * 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.
+ *
+ * Copyright holder is ArangoDB GmbH, Cologne, Germany
+ */
+
+package com.arangodb.springframework.core.mapping;
+
+import com.arangodb.springframework.AbstractArangoTest;
+import com.arangodb.springframework.annotation.Ref;
+import com.arangodb.springframework.core.convert.resolver.LazyLoadingProxy;
+import com.arangodb.springframework.core.mapping.testdata.BasicTestEntity;
+import org.junit.jupiter.api.Test;
+
+import static org.hamcrest.MatcherAssert.assertThat;
+import static org.hamcrest.Matchers.*;
+
+public class LazyLoadingProxyTest extends AbstractArangoTest {
+
+	public static class SingleReferenceLazyTestEntity extends BasicTestEntity {
+		@Ref(lazy = true)
+		private BasicTestEntity entity;
+	}
+
+	@Test
+	public void isResolved() {
+		final BasicTestEntity e1 = new BasicTestEntity();
+		template.insert(e1);
+		final SingleReferenceLazyTestEntity e0 = new SingleReferenceLazyTestEntity();
+		e0.entity = e1;
+		template.insert(e0);
+		final SingleReferenceLazyTestEntity document = template.find(e0.id, SingleReferenceLazyTestEntity.class).get();
+		assertThat(document, is(notNullValue()));
+		assertThat(document.entity, is(notNullValue()));
+		assertThat(document.entity, instanceOf(LazyLoadingProxy.class));
+		assertThat(document.entity, instanceOf(BasicTestEntity.class));
+		assertThat(((LazyLoadingProxy) document.entity).isResolved(), is(false));
+		assertThat(document.entity.getId(), is(e1.getId()));
+		assertThat(((LazyLoadingProxy) document.entity).isResolved(), is(true));
+	}
+
+}