Add ArangoCollection.getDocuments(Collection<String>, Class)

Author: mpv1989

ChangeLog

@@ -2,6 +2,7 @@ v4.2.2 (xxxx-xx-xx)
 ---------------------------
 * added ArangoDatabase.grantAccess(String, Permissions)
 * added ArangoCollection.grantAccess(String, Permissions)
+* added ArangoCollection.getDocuments(Collection<String>, Class)
 
 v4.2.1 (2017-06-20)
 ---------------------------

src/main/java/com/arangodb/ArangoCollection.java

@@ -251,6 +251,22 @@ public <T> T getDocument(final String key, final Class<T> type, final DocumentRe
 		}
 	}
 
+	/**
+	 * Reads multiple documents
+	 * 
+	 * @param keys
+	 *            The keys of the documents
+	 * @param type
+	 *            The type of the documents (POJO class, VPackSlice or String for Json)
+	 * @return the documents and possible errors
+	 * @throws ArangoDBException
+	 */
+	public <T> MultiDocumentEntity<T> getDocuments(final Collection<String> keys, final Class<T> type)
+			throws ArangoDBException {
+		final DocumentReadOptions options = new DocumentReadOptions();
+		return executor.execute(getDocumentsRequest(keys, options), getDocumentsResponseDeserializer(type, options));
+	}
+
 	/**
 	 * Replaces the document with key with the one in the body, provided there is such a document and no precondition is
 	 * violated

src/main/java/com/arangodb/entity/MultiDocumentEntity.java

@@ -26,7 +26,7 @@
  * @author Mark Vollmary
  *
  */
-public class MultiDocumentEntity<E extends DocumentEntity> {
+public class MultiDocumentEntity<E> {
 
 	private Collection<E> documents;
 	private Collection<ErrorEntity> errors;

src/main/java/com/arangodb/internal/InternalArangoCollection.java

@@ -197,6 +197,39 @@ protected Request getDocumentRequest(final String key, final DocumentReadOptions
 		return request;
 	}
 
+	protected Request getDocumentsRequest(final Collection<String> keys, final DocumentReadOptions options) {
+		return new Request(db.name(), RequestType.PUT, executor.createPath(ArangoDBConstants.PATH_API_DOCUMENT, name))
+				.putQueryParam("onlyget", true)
+				.putHeaderParam(ArangoDBConstants.IF_NONE_MATCH, options.getIfNoneMatch())
+				.putHeaderParam(ArangoDBConstants.IF_MATCH, options.getIfMatch()).setBody(util().serialize(keys));
+	}
+
+	protected <T> ResponseDeserializer<MultiDocumentEntity<T>> getDocumentsResponseDeserializer(
+		final Class<T> type,
+		final DocumentReadOptions options) {
+		return new ResponseDeserializer<MultiDocumentEntity<T>>() {
+			@SuppressWarnings("unchecked")
+			@Override
+			public MultiDocumentEntity<T> deserialize(final Response response) throws VPackException {
+				final MultiDocumentEntity<T> multiDocument = new MultiDocumentEntity<T>();
+				final Collection<T> docs = new ArrayList<T>();
+				final Collection<ErrorEntity> errors = new ArrayList<ErrorEntity>();
+				final VPackSlice body = response.getBody();
+				for (final Iterator<VPackSlice> iterator = body.arrayIterator(); iterator.hasNext();) {
+					final VPackSlice next = iterator.next();
+					if (next.get(ArangoDBConstants.ERROR).isTrue()) {
+						errors.add((ErrorEntity) util().deserialize(next, ErrorEntity.class));
+					} else {
+						docs.add((T) util().deserialize(next, type));
+					}
+				}
+				multiDocument.setDocuments(docs);
+				multiDocument.setErrors(errors);
+				return multiDocument;
+			}
+		};
+	}
+
 	protected <T> Request replaceDocumentRequest(
 		final String key,
 		final T value,

src/test/java/com/arangodb/ArangoCollectionTest.java

@@ -27,6 +27,7 @@
 import static org.hamcrest.Matchers.hasItems;
 import static org.hamcrest.Matchers.instanceOf;
 import static org.hamcrest.Matchers.is;
+import static org.hamcrest.Matchers.isOneOf;
 import static org.hamcrest.Matchers.not;
 import static org.hamcrest.Matchers.notNullValue;
 import static org.hamcrest.Matchers.nullValue;
@@ -35,7 +36,9 @@
 import static org.junit.Assert.fail;
 
 import java.util.ArrayList;
+import java.util.Arrays;
 import java.util.Collection;
+import java.util.Collections;
 import java.util.HashMap;
 import java.util.Map;
 
@@ -224,6 +227,41 @@ public void getDocumentWrongKey() {
 		db.collection(COLLECTION_NAME).getDocument("no/no", BaseDocument.class);
 	}
 
+	@Test
+	public void getDocuments() {
+		final Collection<BaseDocument> values = new ArrayList<BaseDocument>();
+		values.add(new BaseDocument("1"));
+		values.add(new BaseDocument("2"));
+		values.add(new BaseDocument("3"));
+		db.collection(COLLECTION_NAME).insertDocuments(values);
+		final MultiDocumentEntity<BaseDocument> documents = db.collection(COLLECTION_NAME)
+				.getDocuments(Arrays.asList("1", "2", "3"), BaseDocument.class);
+		assertThat(documents, is(notNullValue()));
+		assertThat(documents.getDocuments().size(), is(3));
+		for (final BaseDocument document : documents.getDocuments()) {
+			assertThat(document.getId(),
+				isOneOf(COLLECTION_NAME + "/" + "1", COLLECTION_NAME + "/" + "2", COLLECTION_NAME + "/" + "3"));
+		}
+	}
+
+	@Test
+	public void getDocumentsNotFound() {
+		final MultiDocumentEntity<BaseDocument> readResult = db.collection(COLLECTION_NAME)
+				.getDocuments(Collections.singleton("no"), BaseDocument.class);
+		assertThat(readResult, is(notNullValue()));
+		assertThat(readResult.getDocuments().size(), is(0));
+		assertThat(readResult.getErrors().size(), is(1));
+	}
+
+	@Test
+	public void getDocumentsWrongKey() {
+		final MultiDocumentEntity<BaseDocument> readResult = db.collection(COLLECTION_NAME)
+				.getDocuments(Collections.singleton("no/no"), BaseDocument.class);
+		assertThat(readResult, is(notNullValue()));
+		assertThat(readResult.getDocuments().size(), is(0));
+		assertThat(readResult.getErrors().size(), is(1));
+	}
+
 	@Test
 	public void updateDocument() {
 		final BaseDocument doc = new BaseDocument();