[FLINK-6107] Enable LeftCurly check in streaming checkstyle

flink-streaming-java/src/main/java/org/apache/flink/streaming/api/collector/selector/DirectedOutput.java

@@ -55,8 +55,7 @@ public class DirectedOutput<OUT> implements Output<StreamRecord<OUT>> {
 	@SuppressWarnings({"unchecked", "rawtypes"})
 	public DirectedOutput(
 			List<OutputSelector<OUT>> outputSelectors,
-			List<Tuple2<Output<StreamRecord<OUT>>, StreamEdge>> outputs)
-	{
+			List<Tuple2<Output<StreamRecord<OUT>>, StreamEdge>> outputs) {
 		this.outputSelectors = outputSelectors.toArray(new OutputSelector[outputSelectors.size()]);
 
 		this.allOutputs = new Output[outputs.size()];

flink-streaming-java/src/main/java/org/apache/flink/streaming/api/environment/StreamExecutionEnvironment.java

@@ -1709,8 +1709,7 @@ public static StreamExecutionEnvironment createRemoteEnvironment(
 	 * @return A remote environment that executes the program on a cluster.
 	 */
 	public static StreamExecutionEnvironment createRemoteEnvironment(
-			String host, int port, int parallelism, String... jarFiles)
-	{
+			String host, int port, int parallelism, String... jarFiles) {
 		RemoteStreamEnvironment env = new RemoteStreamEnvironment(host, port, jarFiles);
 		env.setParallelism(parallelism);
 		return env;
@@ -1738,8 +1737,7 @@ public static StreamExecutionEnvironment createRemoteEnvironment(
 	 * @return A remote environment that executes the program on a cluster.
 	 */
 	public static StreamExecutionEnvironment createRemoteEnvironment(
-			String host, int port, Configuration clientConfig, String... jarFiles)
-	{
+			String host, int port, Configuration clientConfig, String... jarFiles) {
 		return new RemoteStreamEnvironment(host, port, clientConfig, jarFiles);
 	}
 

flink-streaming-java/src/main/java/org/apache/flink/streaming/api/functions/sink/SocketClientSink.java

@@ -101,8 +101,7 @@ public SocketClientSink(String hostName, int port, SerializationSchema<IN> schem
 	 * @param autoflush Flag to indicate whether the socket stream should be flushed after each message.
 	 */
 	public SocketClientSink(String hostName, int port, SerializationSchema<IN> schema,
-							int maxNumRetries, boolean autoflush)
-	{
+							int maxNumRetries, boolean autoflush) {
 		checkArgument(port > 0 && port < 65536, "port is out of range");
 		checkArgument(maxNumRetries >= -1, "maxNumRetries must be zero or larger (num retries), or -1 (infinite retries)");
 

flink-streaming-java/src/main/java/org/apache/flink/streaming/api/graph/StreamEdge.java

@@ -96,7 +96,9 @@ public List<String> getSelectedNames() {
 		return selectedNames;
 	}
 
-	public OutputTag getOutputTag() { return this.outputTag; }
+	public OutputTag getOutputTag() {
+		return this.outputTag;
+	}
 
 	public StreamPartitioner<?> getPartitioner() {
 		return outputPartitioner;

flink-streaming-java/src/main/java/org/apache/flink/streaming/api/operators/StreamGroupedFold.java

@@ -70,8 +70,7 @@ public void open() throws Exception {
 		}
 
 		try (ByteArrayInputStream bais = new ByteArrayInputStream(serializedInitialValue);
-			DataInputViewStreamWrapper in = new DataInputViewStreamWrapper(bais))
-		{
+			DataInputViewStreamWrapper in = new DataInputViewStreamWrapper(bais)) {
 			initialValue = outTypeSerializer.deserialize(in);
 		}
 

flink-streaming-java/src/main/java/org/apache/flink/streaming/runtime/operators/windowing/AbstractAlignedProcessingTimeWindowOperator.java

@@ -84,8 +84,7 @@ protected AbstractAlignedProcessingTimeWindowOperator(
 			TypeSerializer<KEY> keySerializer,
 			TypeSerializer<STATE> stateTypeSerializer,
 			long windowLength,
-			long windowSlide)
-	{
+			long windowSlide) {
 		super(function);
 
 		if (windowLength < MIN_SLIDE_TIME) {

flink-streaming-java/src/main/java/org/apache/flink/streaming/runtime/operators/windowing/AbstractKeyedTimePanes.java

@@ -101,8 +101,7 @@ protected void traverseAllPanes(KeyMap.TraversalEvaluator<Key, Aggregate> traver
 	public void writeToOutput(
 			final DataOutputView output,
 			final TypeSerializer<Key> keySerializer,
-			final TypeSerializer<Aggregate> aggSerializer) throws IOException
-	{
+			final TypeSerializer<Aggregate> aggSerializer) throws IOException {
 		output.writeInt(BEGIN_OF_STATE_MAGIC_NUMBER);
 
 		int numPanes = getNumPanes();
@@ -125,8 +124,7 @@ public void writeToOutput(
 	public void readFromInput(
 			final DataInputView input,
 			final TypeSerializer<Key> keySerializer,
-			final TypeSerializer<Aggregate> aggSerializer) throws IOException
-	{
+			final TypeSerializer<Aggregate> aggSerializer) throws IOException {
 		validateMagicNumber(BEGIN_OF_STATE_MAGIC_NUMBER, input.readInt());
 		int numPanes = input.readInt();
 

flink-streaming-java/src/main/java/org/apache/flink/streaming/runtime/operators/windowing/AccumulatingKeyedTimePanes.java

@@ -78,8 +78,7 @@ public void addElementToLatestPane(Type element) throws Exception {
 
 	@Override
 	public void evaluateWindow(Collector<Result> out, final TimeWindow window,
-								AbstractStreamOperator<Result> operator) throws Exception
-	{
+								AbstractStreamOperator<Result> operator) throws Exception {
 		if (previousPanes.isEmpty()) {
 			// optimized path for single pane case (tumbling window)
 			for (KeyMap.Entry<Key, ArrayList<Type>> entry : latestPane) {

flink-streaming-java/src/main/java/org/apache/flink/streaming/runtime/operators/windowing/AccumulatingProcessingTimeWindowOperator.java

@@ -49,8 +49,7 @@ public AccumulatingProcessingTimeWindowOperator(
 			TypeSerializer<KEY> keySerializer,
 			TypeSerializer<IN> valueSerializer,
 			long windowLength,
-			long windowSlide)
-	{
+			long windowSlide) {
 		super(function, keySelector, keySerializer,
 				new ArrayListSerializer<>(valueSerializer), windowLength, windowSlide);
 	}

flink-streaming-java/src/main/java/org/apache/flink/streaming/runtime/operators/windowing/AggregatingProcessingTimeWindowOperator.java

@@ -45,8 +45,7 @@ public AggregatingProcessingTimeWindowOperator(
 			TypeSerializer<KEY> keySerializer,
 			TypeSerializer<IN> aggregateSerializer,
 			long windowLength,
-			long windowSlide)
-	{
+			long windowSlide) {
 		super(function, keySelector, keySerializer, aggregateSerializer, windowLength, windowSlide);
 	}
 

flink-streaming-java/src/main/java/org/apache/flink/streaming/runtime/operators/windowing/KeyMap.java

@@ -499,8 +499,7 @@ public static <K, V> void traverseMaps(
 					final KeyMap<K, V>[] maps,
 					final TraversalEvaluator<K, V> visitor,
 					final long touchedTag)
-		throws Exception
-	{
+		throws Exception {
 		// we need to work on the maps in descending size
 		Arrays.sort(maps, CapacityDescendingComparator.INSTANCE);
 
@@ -524,8 +523,7 @@ public static <K, V> void traverseMaps(
 			int mask;
 			for (int rootTable = 0;
 					rootTable < numTables && ((mask = lowBitsMask[rootTable]) & pos) == mask;
-					rootTable++)
-			{
+					rootTable++) {
 				// use that table to gather keys and start collecting keys from the following tables
 				// go over all entries of that slot in the table
 				Entry<K, V> entry = maps[rootTable].table[pos >> shifts[rootTable]];
@@ -563,8 +561,7 @@ private static <K, V> void addEntriesFromChain(
 			TraversalEvaluator<K, V> visitor,
 			K key,
 			long touchedTag,
-			int hashCode) throws Exception
-	{
+			int hashCode) throws Exception {
 		while (entry != null) {
 			if (entry.touchedTag < touchedTag && entry.hashCode == hashCode && entry.key.equals(key)) {
 				entry.touchedTag = touchedTag;

flink-streaming-java/src/main/java/org/apache/flink/streaming/runtime/tasks/OperatorChain.java

@@ -253,8 +253,7 @@ private <T> Output<StreamRecord<T>> createOutputCollector(
 			Map<Integer, StreamConfig> chainedConfigs,
 			ClassLoader userCodeClassloader,
 			Map<StreamEdge, RecordWriterOutput<?>> streamOutputs,
-			List<StreamOperator<?>> allOperators)
-	{
+			List<StreamOperator<?>> allOperators) {
 		List<Tuple2<Output<StreamRecord<T>>, StreamEdge>> allOutputs = new ArrayList<>(4);
 
 		// create collectors for the network outputs
@@ -326,8 +325,7 @@ private <IN, OUT> Output<StreamRecord<IN>> createChainedOperator(
 			ClassLoader userCodeClassloader,
 			Map<StreamEdge, RecordWriterOutput<?>> streamOutputs,
 			List<StreamOperator<?>> allOperators,
-			OutputTag<IN> outputTag)
-	{
+			OutputTag<IN> outputTag) {
 		// create the output that the operator writes to first. this may recursively create more operators
 		Output<StreamRecord<OUT>> output = createOutputCollector(
 				containingTask, operatorConfig, chainedConfigs, userCodeClassloader, streamOutputs, allOperators);

flink-streaming-java/src/main/java/org/apache/flink/streaming/runtime/tasks/SystemProcessingTimeService.java

@@ -169,8 +169,7 @@ public void quiesceAndAwaitPending() throws InterruptedException {
 	@Override
 	public void shutdownService() {
 		if (status.compareAndSet(STATUS_ALIVE, STATUS_SHUTDOWN) ||
-				status.compareAndSet(STATUS_QUIESCED, STATUS_SHUTDOWN))
-		{
+				status.compareAndSet(STATUS_QUIESCED, STATUS_SHUTDOWN)) {
 			timerService.shutdownNow();
 		}
 	}

flink-streaming-java/src/main/java/org/apache/flink/streaming/util/keys/KeySelectorUtil.java

@@ -91,8 +91,7 @@ else if (typeInfo instanceof PrimitiveArrayTypeInfo) {
 
 
 	public static <X, K> KeySelector<X, K> getSelectorForOneKey(
-			Keys<X> keys, Partitioner<K> partitioner, TypeInformation<X> typeInfo, ExecutionConfig executionConfig)
-	{
+			Keys<X> keys, Partitioner<K> partitioner, TypeInformation<X> typeInfo, ExecutionConfig executionConfig) {
 		if (!(typeInfo instanceof CompositeType)) {
 			throw new InvalidTypesException(
 					"This key operation requires a composite type such as Tuples, POJOs, case classes, etc");

tools/maven/strict-checkstyle.xml

@@ -402,10 +402,10 @@ This file is based on the checkstyle file of Apache Beam.
           <!--value="^(package .*;\s*)|(import .*;\s*)|( *\* .*https?://.*)$"/>-->
     <!--</module>-->
 
-    <!--<module name="LeftCurly">-->
-      <!--&lt;!&ndash; Checks for placement of the left curly brace ('{'). &ndash;&gt;-->
-      <!--<property name="severity" value="error"/>-->
-    <!--</module>-->
+    <module name="LeftCurly">
+      <!-- Checks for placement of the left curly brace ('{'). -->
+      <property name="severity" value="error"/>
+    </module>
 
     <!--<module name="RightCurly">-->
       <!--&lt;!&ndash; Checks right curlies on CATCH, ELSE, and TRY blocks are on-->