Use aggregate queries (Count) with Azure CosmosDB Java SDK

I'm addicted to using aggregate queries in CosmosDB from the JavaSDK, so I'll take note of it.

If you do not set the VALUE clause in the query, you will get the following error:

java.lang.IllegalStateException: com.microsoft.azure.documentdb.DocumentClientException: Message: {"Errors":["Cross partition query only supports 'VALUE <AggreateFunc>' for aggregates."]}
Caused by: com.microsoft.azure.documentdb.DocumentClientException: Message: {"Errors":["Cross partition query only supports 'VALUE <AggreateFunc>' for aggregates."]}

Also, if setEnableCrossPartitionQuery is not set to true, the following error will occur.

java.lang.IllegalStateException: com.microsoft.azure.documentdb.DocumentClientException: Cross partition query is required but disabled. Please set x-ms-documentdb-query-enablecrosspartition to true, specify x-ms-documentdb-partitionkey, or revise your query to avoid this exception.
Caused by: com.microsoft.azure.documentdb.DocumentClientException: Cross partition query is required but disabled. Please set x-ms-documentdb-query-enablecrosspartition to true, specify x-ms-documentdb-partitionkey, or revise your query to avoid this exception.

Below is the Java code.

		// Azure Cosmos DB Libraries for Java
		// https://docs.microsoft.com/ja-jp/java/api/overview/azure/cosmosdb?view=azure-java-stable

		String host = "yourhost";
		String container_id = "yourcontainer";
		String database = "yourdatabase";

		// Get key from Azure Web Console
		// read write key
		String key = "yourkey";

		String endPoint = "https://" + host + ".documents.azure.com:443";

		DocumentClient client = new DocumentClient(endPoint, key, //
				new ConnectionPolicy(), ConsistencyLevel.Session);

		String collectionLink = String.format("/dbs/%s/colls/%s", database, container_id);

		String q = String.format("SELECT VALUE count(1) FROM c");
		// IF (without 'VALUE' in query)
//		java.lang.IllegalStateException: com.microsoft.azure.documentdb.DocumentClientException: Message: {"Errors":["Cross partition query only supports 'VALUE <AggreateFunc>' for aggregates."]}
//		Caused by: com.microsoft.azure.documentdb.DocumentClientException: Message: {"Errors":["Cross partition query only supports 'VALUE <AggreateFunc>' for aggregates."]}

		FeedOptions feedOptions = new FeedOptions();
		feedOptions.setEnableCrossPartitionQuery(true);
		// IF (EnableCrossPartitionQuery = false)
//		java.lang.IllegalStateException: com.microsoft.azure.documentdb.DocumentClientException: Cross partition query is required but disabled. Please set x-ms-documentdb-query-enablecrosspartition to true, specify x-ms-documentdb-partitionkey, or revise your query to avoid this exception.
//		Caused by: com.microsoft.azure.documentdb.DocumentClientException: Cross partition query is required but disabled. Please set x-ms-documentdb-query-enablecrosspartition to true, specify x-ms-documentdb-partitionkey, or revise your query to avoid this exception.

		try {

			List<Object> results = client //
					.queryAggregateValues(collectionLink, q, feedOptions);

			System.err.println(results.get(0));

		} catch (Exception e) {
			e.printStackTrace();
		} finally {
			client.close();
		}

that's all.