[Streaming]Format java code using IDEA (#10440)

streaming/java/streaming-api/src/main/java/io/ray/streaming/api/context/ClusterStarter.java

@@ -17,6 +17,7 @@ import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
 class ClusterStarter {
+
   private static final Logger LOG = LoggerFactory.getLogger(ClusterStarter.class);
   private static final String PLASMA_STORE_SOCKET_NAME = "/tmp/ray/plasma_store_socket";
   private static final String RAYLET_SOCKET_NAME = "/tmp/ray/raylet_socket";

streaming/java/streaming-api/src/main/java/io/ray/streaming/api/context/StreamingContext.java

@@ -23,6 +23,7 @@ import org.slf4j.LoggerFactory;
  * Encapsulate the context information of a streaming Job.
  */
 public class StreamingContext implements Serializable {
+
   private static final Logger LOG = LoggerFactory.getLogger(StreamingContext.class);
 
   private transient AtomicInteger idGenerator;

streaming/java/streaming-api/src/main/java/io/ray/streaming/api/function/RichFunction.java

@@ -3,21 +3,21 @@ package io.ray.streaming.api.function;
 import io.ray.streaming.api.context.RuntimeContext;
 
 /**
- * An interface for all user-defined functions to define the life cycle methods of the
- * functions, and access the task context where the functions get executed.
+ * An interface for all user-defined functions to define the life cycle methods of the functions,
+ * and access the task context where the functions get executed.
  */
 public interface RichFunction extends Function {
 
   /**
    * Initialization method for user function which called before the first call to the user
    * function.
+   *
    * @param runtimeContext runtime context
    */
   void open(RuntimeContext runtimeContext);
 
   /**
-   * Tear-down method for the user function which called after the last call to
-   * the user function.
+   * Tear-down method for the user function which called after the last call to the user function.
    */
   void close();
 

streaming/java/streaming-api/src/main/java/io/ray/streaming/api/function/impl/FilterFunction.java

@@ -3,8 +3,8 @@ package io.ray.streaming.api.function.impl;
 import io.ray.streaming.api.function.Function;
 
 /**
- * A filter function is a predicate applied individually to each record.
- * The predicate decides whether to keep the element, or to discard it.
+ * A filter function is a predicate applied individually to each record. The predicate decides
+ * whether to keep the element, or to discard it.
  *
  * @param <T> type of the input data.
  */

streaming/java/streaming-api/src/main/java/io/ray/streaming/api/function/internal/Functions.java

@@ -10,6 +10,7 @@ import io.ray.streaming.api.function.RichFunction;
 public class Functions {
 
   private static class DefaultRichFunction implements RichFunction {
+
     private final Function function;
 
     private DefaultRichFunction(Function function) {

streaming/java/streaming-api/src/main/java/io/ray/streaming/api/partition/Partition.java

@@ -14,7 +14,7 @@ public interface Partition<T> extends Function {
    * Given a record and downstream partitions, determine which partition(s) should receive the
    * record.
    *
-   * @param record       The record.
+   * @param record The record.
    * @param numPartition num of partitions
    * @return IDs of the downstream partitions that should receive the record.
    */

streaming/java/streaming-api/src/main/java/io/ray/streaming/api/partition/impl/BroadcastPartition.java

@@ -7,6 +7,7 @@ import java.util.stream.IntStream;
  * Broadcast the record to all downstream partitions.
  */
 public class BroadcastPartition<T> implements Partition<T> {
+
   private int[] partitions = new int[0];
 
   public BroadcastPartition() {

streaming/java/streaming-api/src/main/java/io/ray/streaming/api/partition/impl/ForwardPartition.java

@@ -10,6 +10,7 @@ import io.ray.streaming.api.partition.Partition;
  * @param <T> Type of the input record.
  */
 public class ForwardPartition<T> implements Partition<T> {
+
   private int[] partitions = new int[] {0};
 
   @Override

streaming/java/streaming-api/src/main/java/io/ray/streaming/api/partition/impl/KeyPartition.java

@@ -10,6 +10,7 @@ import io.ray.streaming.message.KeyRecord;
  * @param <T> Type of the input record.
  */
 public class KeyPartition<K, T> implements Partition<KeyRecord<K, T>> {
+
   private int[] partitions = new int[1];
 
   @Override

streaming/java/streaming-api/src/main/java/io/ray/streaming/api/partition/impl/RoundRobinPartition.java

@@ -8,6 +8,7 @@ import io.ray.streaming.api.partition.Partition;
  * @param <T> Type of the input record.
  */
 public class RoundRobinPartition<T> implements Partition<T> {
+
   private int seq;
   private int[] partitions = new int[1];
 

streaming/java/streaming-api/src/main/java/io/ray/streaming/api/stream/DataStream.java

@@ -22,7 +22,6 @@ import java.util.List;
 
 /**
  * Represents a stream of data.
- *
  * <p>This class defines all the streaming operations.
  *
  * @param <T> Type of data in the stream.
@@ -33,9 +32,10 @@ public class DataStream<T> extends Stream<DataStream<T>, T> {
     super(streamingContext, streamOperator);
   }
 
-  public DataStream(StreamingContext streamingContext,
-                    StreamOperator streamOperator,
-                    Partition<T> partition) {
+  public DataStream(
+      StreamingContext streamingContext,
+      StreamOperator streamOperator,
+      Partition<T> partition) {
     super(streamingContext, streamOperator, partition);
   }
 
@@ -43,15 +43,16 @@ public class DataStream<T> extends Stream<DataStream<T>, T> {
     super(input, streamOperator);
   }
 
-  public <R> DataStream(DataStream<R> input,
-                        StreamOperator streamOperator,
-                        Partition<T> partition) {
+  public <R> DataStream(
+      DataStream<R> input,
+      StreamOperator streamOperator,
+      Partition<T> partition) {
     super(input, streamOperator, partition);
   }
 
   /**
-   * Create a java stream that reference passed python stream.
-   * Changes in new stream will be reflected in referenced stream and vice versa
+   * Create a java stream that reference passed python stream. Changes in new stream will be
+   * reflected in referenced stream and vice versa
    */
   public DataStream(PythonDataStream referencedStream) {
     super(referencedStream);
@@ -84,8 +85,8 @@ public class DataStream<T> extends Stream<DataStream<T>, T> {
   }
 
   /**
-   * Apply union transformations to this stream by merging {@link DataStream} outputs of
-   * the same type with each other.
+   * Apply union transformations to this stream by merging {@link DataStream} outputs of the same
+   * type with each other.
    *
    * @param stream The DataStream to union output with.
    * @param others The other DataStreams to union output with.
@@ -100,8 +101,8 @@ public class DataStream<T> extends Stream<DataStream<T>, T> {
   }
 
   /**
-   * Apply union transformations to this stream by merging {@link DataStream} outputs of
-   * the same type with each other.
+   * Apply union transformations to this stream by merging {@link DataStream} outputs of the same
+   * type with each other.
    *
    * @param streams The DataStreams to union output with.
    * @return A new UnionStream.
@@ -177,8 +178,8 @@ public class DataStream<T> extends Stream<DataStream<T>, T> {
   }
 
   /**
-   * If parent stream is a python stream, we can't call partition related methods
-   * in the java stream.
+   * If parent stream is a python stream, we can't call partition related methods in the java
+   * stream.
    */
   private void checkPartitionCall() {
     if (getInputStream() != null && getInputStream().getLanguage() == Language.PYTHON) {
@@ -188,9 +189,9 @@ public class DataStream<T> extends Stream<DataStream<T>, T> {
   }
 
   /**
-   * Convert this stream as a python stream.
-   * The converted stream and this stream are the same logical stream, which has same stream id.
-   * Changes in converted stream will be reflected in this stream and vice versa.
+   * Convert this stream as a python stream. The converted stream and this stream are the same
+   * logical stream, which has same stream id. Changes in converted stream will be reflected in this
+   * stream and vice versa.
    */
   public PythonDataStream asPythonStream() {
     return new PythonDataStream(this);

streaming/java/streaming-api/src/main/java/io/ray/streaming/api/stream/JoinStream.java

@@ -13,6 +13,7 @@ import java.io.Serializable;
  * @param <O> Type of the data in the joined stream.
  */
 public class JoinStream<L, R, O> extends DataStream<L> {
+
   private final DataStream<R> rightStream;
 
   public JoinStream(DataStream<L> leftStream, DataStream<R> rightStream) {
@@ -37,6 +38,7 @@ public class JoinStream<L, R, O> extends DataStream<L> {
    * @param <K> Type of the join key.
    */
   class Where<K> implements Serializable {
+
     private JoinStream<L, R, O> joinStream;
     private KeyFunction<L, K> leftKeyByFunction;
 
@@ -56,12 +58,14 @@ public class JoinStream<L, R, O> extends DataStream<L> {
    * @param <K> Type of the join key.
    */
   class Equal<K> implements Serializable {
+
     private JoinStream<L, R, O> joinStream;
     private KeyFunction<L, K> leftKeyByFunction;
     private KeyFunction<R, K> rightKeyByFunction;
 
-    Equal(JoinStream<L, R, O> joinStream, KeyFunction<L, K> leftKeyByFunction,
-          KeyFunction<R, K> rightKeyByFunction) {
+    Equal(
+        JoinStream<L, R, O> joinStream, KeyFunction<L, K> leftKeyByFunction,
+        KeyFunction<R, K> rightKeyByFunction) {
       this.joinStream = joinStream;
       this.leftKeyByFunction = leftKeyByFunction;
       this.rightKeyByFunction = rightKeyByFunction;

streaming/java/streaming-api/src/main/java/io/ray/streaming/api/stream/KeyDataStream.java

@@ -23,8 +23,8 @@ public class KeyDataStream<K, T> extends DataStream<T> {
   }
 
   /**
-   * Create a java stream that reference passed python stream.
-   * Changes in new stream will be reflected in referenced stream and vice versa
+   * Create a java stream that reference passed python stream. Changes in new stream will be
+   * reflected in referenced stream and vice versa
    */
   public KeyDataStream(PythonDataStream referencedStream) {
     super(referencedStream);
@@ -53,9 +53,9 @@ public class KeyDataStream<K, T> extends DataStream<T> {
   }
 
   /**
-   * Convert this stream as a python stream.
-   * The converted stream and this stream are the same logical stream, which has same stream id.
-   * Changes in converted stream will be reflected in this stream and vice versa.
+   * Convert this stream as a python stream. The converted stream and this stream are the same
+   * logical stream, which has same stream id. Changes in converted stream will be reflected in this
+   * stream and vice versa.
    */
   public PythonKeyDataStream asPythonStream() {
     return new PythonKeyDataStream(this);

streaming/java/streaming-api/src/main/java/io/ray/streaming/api/stream/Stream.java

@@ -21,6 +21,7 @@ import java.util.Map;
  */
 public abstract class Stream<S extends Stream<S, T>, T>
     implements Serializable {
+
   private final int id;
   private final StreamingContext streamingContext;
   private final Stream inputStream;
@@ -34,9 +35,10 @@ public abstract class Stream<S extends Stream<S, T>, T>
     this(streamingContext, null, streamOperator, getForwardPartition(streamOperator));
   }
 
-  public Stream(StreamingContext streamingContext,
-                StreamOperator streamOperator,
-                Partition<T> partition) {
+  public Stream(
+      StreamingContext streamingContext,
+      StreamOperator streamOperator,
+      Partition<T> partition) {
     this(streamingContext, null, streamOperator, partition);
   }
 
@@ -49,10 +51,11 @@ public abstract class Stream<S extends Stream<S, T>, T>
     this(inputStream.getStreamingContext(), inputStream, streamOperator, partition);
   }
 
-  protected Stream(StreamingContext streamingContext,
-                   Stream inputStream,
-                   StreamOperator streamOperator,
-                   Partition<T> partition) {
+  protected Stream(
+      StreamingContext streamingContext,
+      Stream inputStream,
+      StreamOperator streamOperator,
+      Partition<T> partition) {
     this.streamingContext = streamingContext;
     this.inputStream = inputStream;
     this.operator = streamOperator;
@@ -64,8 +67,8 @@ public abstract class Stream<S extends Stream<S, T>, T>
   }
 
   /**
-   * Create a proxy stream of original stream.
-   * Changes in new stream will be reflected in original stream and vice versa
+   * Create a proxy stream of original stream. Changes in new stream will be reflected in original
+   * stream and vice versa
    */
   protected Stream(Stream originalStream) {
     this.originalStream = originalStream;
@@ -183,8 +186,8 @@ public abstract class Stream<S extends Stream<S, T>, T>
   }
 
   /**
-   * Set the partition function of this {@link Stream} so that output elements are forwarded to
-   * next operator locally.
+   * Set the partition function of this {@link Stream} so that output elements are forwarded to next
+   * operator locally.
    */
   public S forward() {
     return setPartition(getForwardPartition(operator));

streaming/java/streaming-api/src/main/java/io/ray/streaming/api/stream/StreamSink.java

@@ -8,6 +8,7 @@ import io.ray.streaming.operator.StreamOperator;
  * @param <T> Type of the input data of this sink.
  */
 public abstract class StreamSink<T> extends Stream<StreamSink<T>, T> {
+
   public StreamSink(Stream inputStream, StreamOperator streamOperator) {
     super(inputStream, streamOperator);
   }

streaming/java/streaming-api/src/main/java/io/ray/streaming/api/stream/StreamSource.java

@@ -6,4 +6,5 @@ package io.ray.streaming.api.stream;
  * @param <T> The type of StreamSource data.
  */
 public interface StreamSource<T> {
+
 }

streaming/java/streaming-api/src/main/java/io/ray/streaming/api/stream/UnionStream.java

@@ -6,13 +6,13 @@ import java.util.List;
 
 /**
  * Represents a union DataStream.
- *
  * <p>This stream does not create a physical operation, it only affects how upstream data are
- *  connected to downstream data.
+ * connected to downstream data.
  *
  * @param <T> The type of union data.
  */
 public class UnionStream<T> extends DataStream<T> {
+
   private List<DataStream<T>> unionStreams;
 
   public UnionStream(DataStream<T> input, List<DataStream<T>> streams) {

streaming/java/streaming-api/src/main/java/io/ray/streaming/jobgraph/JobGraph.java

@@ -30,8 +30,9 @@ public class JobGraph implements Serializable {
     this.jobEdges = new ArrayList<>();
   }
 
-  public JobGraph(String jobName, Map<String, String> jobConfig,
-                  List<JobVertex> jobVertices, List<JobEdge> jobEdges) {
+  public JobGraph(
+      String jobName, Map<String, String> jobConfig,
+      List<JobVertex> jobVertices, List<JobEdge> jobEdges) {
     this.jobName = jobName;
     this.jobConfig = jobConfig;
     this.jobVertices = jobVertices;
@@ -40,8 +41,8 @@ public class JobGraph implements Serializable {
   }
 
   /**
-   * Generate direct-graph(made up of a set of vertices and connected by edges)
-   * by current job graph for simple log printing.
+   * Generate direct-graph(made up of a set of vertices and connected by edges) by current job graph
+   * for simple log printing.
    *
    * @return Digraph in string type.
    */

streaming/java/streaming-api/src/main/java/io/ray/streaming/jobgraph/JobGraphBuilder.java

@@ -19,6 +19,7 @@ import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
 public class JobGraphBuilder {
+
   private static final Logger LOG = LoggerFactory.getLogger(JobGraphBuilder.class);
 
   private JobGraph jobGraph;
@@ -34,8 +35,9 @@ public class JobGraphBuilder {
     this(streamSinkList, jobName, new HashMap<>());
   }
 
-  public JobGraphBuilder(List<StreamSink> streamSinkList, String jobName,
-                         Map<String, String> jobConfig) {
+  public JobGraphBuilder(
+      List<StreamSink> streamSinkList, String jobName,
+      Map<String, String> jobConfig) {
     this.jobGraph = new JobGraph(jobName, jobConfig);
     this.streamSinkList = streamSinkList;
     this.edgeIdGenerator = new AtomicInteger(0);
@@ -98,7 +100,7 @@ public class JobGraphBuilder {
 
       // process join stream
       if (stream instanceof JoinStream) {
-        DataStream rightStream =  ((JoinStream) stream).getRightStream();
+        DataStream rightStream = ((JoinStream) stream).getRightStream();
         this.jobGraph.addEdge(
             new JobEdge(rightStream.getId(), vertexId, rightStream.getPartition()));
         processStream(rightStream);

streaming/java/streaming-api/src/main/java/io/ray/streaming/jobgraph/JobGraphOptimizer.java

@@ -21,10 +21,11 @@ import java.util.stream.Collectors;
 import org.apache.commons.lang3.tuple.Pair;
 
 /**
- * Optimize job graph by chaining some operators so that some operators can be run in the
- * same thread.
+ * Optimize job graph by chaining some operators so that some operators can be run in the same
+ * thread.
  */
 public class JobGraphOptimizer {
+
   private final JobGraph jobGraph;
   private Set<JobVertex> visited = new HashSet<>();
   // vertex id -> vertex
@@ -89,7 +90,8 @@ public class JobGraphOptimizer {
       mergedVertex = headVertex;
     } else {
       List<StreamOperator> operators = verticesToMerge.stream()
-          .map(v -> vertexMap.get(v.getVertexId()).getStreamOperator())
+          .map(v -> vertexMap.get(v.getVertexId())
+              .getStreamOperator())
           .collect(Collectors.toList());
       List<Map<String, String>> configs = verticesToMerge.stream()
           .map(v -> vertexMap.get(v.getVertexId()).getConfig())
@@ -99,7 +101,8 @@ public class JobGraphOptimizer {
         operator = ChainedOperator.newChainedOperator(operators, configs);
       } else {
         List<PythonOperator> pythonOperators = operators.stream()
-            .map(o -> (PythonOperator) o).collect(Collectors.toList());
+            .map(o -> (PythonOperator) o)
+            .collect(Collectors.toList());
         operator = new ChainedPythonOperator(pythonOperators, configs);
       }
       // chained operator config is placed into `ChainedOperator`.
@@ -156,9 +159,10 @@ public class JobGraphOptimizer {
     }
   }
 
-  private boolean canBeChained(JobVertex precedingVertex,
-                               JobVertex succeedingVertex,
-                               JobEdge edge) {
+  private boolean canBeChained(
+      JobVertex precedingVertex,
+      JobVertex succeedingVertex,
+      JobEdge edge) {
     if (jobGraph.getVertexOutputEdges(precedingVertex.getVertexId()).size() > 1 ||
         jobGraph.getVertexInputEdges(succeedingVertex.getVertexId()).size() > 1) {
       return false;

streaming/java/streaming-api/src/main/java/io/ray/streaming/jobgraph/JobVertex.java

@@ -18,11 +18,12 @@ public class JobVertex implements Serializable {
   private StreamOperator streamOperator;
   private Map<String, String> config;
 
-  public JobVertex(int vertexId,
-                   int parallelism,
-                   VertexType vertexType,
-                   StreamOperator streamOperator,
-                   Map<String, String> config) {
+  public JobVertex(
+      int vertexId,
+      int parallelism,
+      VertexType vertexType,
+      StreamOperator streamOperator,
+      Map<String, String> config) {
     this.vertexId = vertexId;
     this.parallelism = parallelism;
     this.vertexType = vertexType;

streaming/java/streaming-api/src/main/java/io/ray/streaming/message/Record.java

@@ -4,6 +4,7 @@ import java.io.Serializable;
 import java.util.Objects;
 
 public class Record<T> implements Serializable {
+
   protected transient String stream;
   protected T value;
 

streaming/java/streaming-api/src/main/java/io/ray/streaming/operator/StreamOperator.java

@@ -11,6 +11,7 @@ import io.ray.streaming.message.Record;
 import java.util.List;
 
 public abstract class StreamOperator<F extends Function> implements Operator {
+
   protected final String name;
   protected F function;
   protected RichFunction richFunction;

streaming/java/streaming-api/src/main/java/io/ray/streaming/operator/chain/ChainedOperator.java

@@ -23,6 +23,7 @@ import java.util.stream.Collectors;
  * Abstract base class for chained operators.
  */
 public abstract class ChainedOperator extends StreamOperator<Function> {
+
   protected final List<StreamOperator> operators;
   protected final Operator headOperator;
   protected final Operator tailOperator;
@@ -43,7 +44,8 @@ public abstract class ChainedOperator extends StreamOperator<Function> {
   public void open(List<Collector> collectorList, RuntimeContext runtimeContext) {
     // Dont' call super.open() as we `open` every operator separately.
     List<ForwardCollector> succeedingCollectors = operators.stream().skip(1)
-        .map(operator -> new ForwardCollector((OneInputOperator) operator))
+        .map(operator -> new ForwardCollector(
+            (OneInputOperator) operator))
         .collect(Collectors.toList());
     for (int i = 0; i < operators.size() - 1; i++) {
       StreamOperator operator = operators.get(i);
@@ -113,6 +115,7 @@ public abstract class ChainedOperator extends StreamOperator<Function> {
 
   static class ChainedSourceOperator<T> extends ChainedOperator
       implements SourceOperator<T> {
+
     private final SourceOperator<T> sourceOperator;
 
     @SuppressWarnings("unchecked")
@@ -135,6 +138,7 @@ public abstract class ChainedOperator extends StreamOperator<Function> {
 
   static class ChainedOneInputOperator<T> extends ChainedOperator
       implements OneInputOperator<T> {
+
     private final OneInputOperator<T> inputOperator;
 
     @SuppressWarnings("unchecked")
@@ -152,6 +156,7 @@ public abstract class ChainedOperator extends StreamOperator<Function> {
 
   static class ChainedTwoInputOperator<L, R> extends ChainedOperator
       implements TwoInputOperator<L, R> {
+
     private final TwoInputOperator<L, R> inputOperator;
 
     @SuppressWarnings("unchecked")

streaming/java/streaming-api/src/main/java/io/ray/streaming/operator/chain/ForwardCollector.java

@@ -5,6 +5,7 @@ import io.ray.streaming.message.Record;
 import io.ray.streaming.operator.OneInputOperator;
 
 class ForwardCollector implements Collector<Record> {
+
   private final OneInputOperator succeedingOperator;
 
   ForwardCollector(OneInputOperator succeedingOperator) {

streaming/java/streaming-api/src/main/java/io/ray/streaming/operator/impl/JoinOperator.java

@@ -17,6 +17,7 @@ import io.ray.streaming.operator.TwoInputOperator;
  */
 public class JoinOperator<L, R, K, O> extends StreamOperator<JoinFunction<L, R, O>> implements
     TwoInputOperator<L, R> {
+
   public JoinOperator() {
 
   }

streaming/java/streaming-api/src/main/java/io/ray/streaming/operator/impl/SourceOperatorImpl.java

@@ -13,6 +13,7 @@ import java.util.List;
 
 public class SourceOperatorImpl<T> extends StreamOperator<SourceFunction<T>>
     implements SourceOperator {
+
   private SourceContextImpl sourceContext;
 
   public SourceOperatorImpl(SourceFunction<T> function) {
@@ -47,6 +48,7 @@ public class SourceOperatorImpl<T> extends StreamOperator<SourceFunction<T>>
   }
 
   class SourceContextImpl implements SourceContext<T> {
+
     private List<Collector> collectors;
 
     public SourceContextImpl(List<Collector> collectors) {

streaming/java/streaming-api/src/main/java/io/ray/streaming/python/PythonFunction.java

@@ -7,20 +7,18 @@ import org.apache.commons.lang3.StringUtils;
 
 /**
  * Represents a user defined python function.
- *
  * <p>Python worker can use information in this class to create a function object.</p>
- *
  * <p>If this object is constructed from serialized python function,
- * python worker can deserialize it to create python function directly.
- * If this object is constructed from moduleName and className/functionName,
- * python worker will use `importlib` to load python function.</p>
- *
+ * python worker can deserialize it to create python function directly. If this object is
+ * constructed from moduleName and className/functionName, python worker will use `importlib` to
+ * load python function.</p>
  * <p>If the python data stream api is invoked from python, `function` will be not null.</p>
  * <p>If the python data stream api is invoked from java, `moduleName` and
  * `functionName` will be not null.</p>
  * <p>
  */
 public class PythonFunction implements Function {
+
   public enum FunctionInterface {
     SOURCE_FUNCTION("SourceFunction"),
     MAP_FUNCTION("MapFunction"),
@@ -47,8 +45,8 @@ public class PythonFunction implements Function {
   // null if this function is constructed from serialized python function.
   private final String functionName;
   /**
-   * FunctionInterface can be used to validate python function,
-   * and look up operator class from FunctionInterface.
+   * FunctionInterface can be used to validate python function, and look up operator class from
+   * FunctionInterface.
    */
   private String functionInterface;
 
@@ -69,10 +67,12 @@ public class PythonFunction implements Function {
    *
    * @param moduleName module name of streaming function.
    * @param functionName function name of streaming function. {@code functionName} is the name
-   *     of a python function, or class name of subclass of `ray.streaming.function.`
+   *     of a
+   *     python function, or class name of subclass of `ray.streaming.function.`
    */
-  public PythonFunction(String moduleName,
-                        String functionName) {
+  public PythonFunction(
+      String moduleName,
+      String functionName) {
     Preconditions.checkArgument(StringUtils.isNotBlank(moduleName));
     Preconditions.checkArgument(StringUtils.isNotBlank(functionName));
     this.function = null;

streaming/java/streaming-api/src/main/java/io/ray/streaming/python/PythonOperator.java

@@ -17,6 +17,7 @@ import java.util.stream.Collectors;
  */
 @SuppressWarnings("unchecked")
 public class PythonOperator extends StreamOperator {
+
   private final String moduleName;
   private final String className;
 
@@ -80,7 +81,7 @@ public class PythonOperator extends StreamOperator {
     StringBuilder builder = new StringBuilder();
     builder.append(PythonOperator.class.getSimpleName()).append("[");
     if (function != null) {
-      builder.append(((PythonFunction)function).toSimpleString());
+      builder.append(((PythonFunction) function).toSimpleString());
     } else {
       builder.append(moduleName).append(".").append(className);
     }
@@ -101,6 +102,7 @@ public class PythonOperator extends StreamOperator {
   }
 
   public static class ChainedPythonOperator extends PythonOperator {
+
     private final List<PythonOperator> operators;
     private final PythonOperator headOperator;
     private final PythonOperator tailOperator;

streaming/java/streaming-api/src/main/java/io/ray/streaming/python/PythonPartition.java

@@ -8,16 +8,15 @@ import org.apache.commons.lang3.StringUtils;
 /**
  * Represents a python partition function.
  * <p>
- * Python worker can create a partition object using information in this
- * PythonPartition.
+ * Python worker can create a partition object using information in this PythonPartition.
  * <p>
- * If this object is constructed from serialized python partition,
- * python worker can deserialize it to create python partition directly.
- * If this object is constructed from moduleName and className/functionName,
- * python worker will use `importlib` to load python partition function.
+ * If this object is constructed from serialized python partition, python worker can deserialize it
+ * to create python partition directly. If this object is constructed from moduleName and
+ * className/functionName, python worker will use `importlib` to load python partition function.
  * <p>
  */
 public class PythonPartition implements Partition<Object> {
+
   public static final PythonPartition BroadcastPartition = new PythonPartition(
       "ray.streaming.partition", "BroadcastPartition");
   public static final PythonPartition KeyPartition = new PythonPartition(

streaming/java/streaming-api/src/main/java/io/ray/streaming/python/stream/PythonDataStream.java

@@ -18,14 +18,16 @@ import java.util.List;
  */
 public class PythonDataStream extends Stream<PythonDataStream, Object> implements PythonStream {
 
-  protected PythonDataStream(StreamingContext streamingContext,
-                             PythonOperator pythonOperator) {
+  protected PythonDataStream(
+      StreamingContext streamingContext,
+      PythonOperator pythonOperator) {
     super(streamingContext, pythonOperator);
   }
 
-  protected PythonDataStream(StreamingContext streamingContext,
-                             PythonOperator pythonOperator,
-                             Partition<Object> partition) {
+  protected PythonDataStream(
+      StreamingContext streamingContext,
+      PythonOperator pythonOperator,
+      Partition<Object> partition) {
     super(streamingContext, pythonOperator, partition);
   }
 
@@ -33,15 +35,16 @@ public class PythonDataStream extends Stream<PythonDataStream, Object> implement
     super(input, pythonOperator);
   }
 
-  public PythonDataStream(PythonDataStream input,
-                          PythonOperator pythonOperator,
-                          Partition<Object> partition) {
+  public PythonDataStream(
+      PythonDataStream input,
+      PythonOperator pythonOperator,
+      Partition<Object> partition) {
     super(input, pythonOperator, partition);
   }
 
   /**
-   * Create a python stream that reference passed java stream.
-   * Changes in new stream will be reflected in referenced stream and vice versa
+   * Create a python stream that reference passed java stream. Changes in new stream will be
+   * reflected in referenced stream and vice versa
    */
   public PythonDataStream(DataStream referencedStream) {
     super(referencedStream);
@@ -85,8 +88,8 @@ public class PythonDataStream extends Stream<PythonDataStream, Object> implement
    * Apply a filter function to this stream.
    *
    * @param func The python FilterFunction.
-   * @return A new PythonDataStream that contains only the elements satisfying
-   *     the given filter predicate.
+   * @return A new PythonDataStream that contains only the elements satisfying the given filter
+   *     predicate.
    */
   public PythonDataStream filter(PythonFunction func) {
     func.setFunctionInterface(FunctionInterface.FILTER_FUNCTION);
@@ -94,8 +97,8 @@ public class PythonDataStream extends Stream<PythonDataStream, Object> implement
   }
 
   /**
-   * Apply union transformations to this stream by merging {@link PythonDataStream} outputs of
-   * the same type with each other.
+   * Apply union transformations to this stream by merging {@link PythonDataStream} outputs of the
+   * same type with each other.
    *
    * @param stream The DataStream to union output with.
    * @param others The other DataStreams to union output with.
@@ -109,8 +112,8 @@ public class PythonDataStream extends Stream<PythonDataStream, Object> implement
   }
 
   /**
-   * Apply union transformations to this stream by merging {@link PythonDataStream} outputs of
-   * the same type with each other.
+   * Apply union transformations to this stream by merging {@link PythonDataStream} outputs of the
+   * same type with each other.
    *
    * @param streams The DataStreams to union output with.
    * @return A new UnionStream.
@@ -178,8 +181,8 @@ public class PythonDataStream extends Stream<PythonDataStream, Object> implement
   }
 
   /**
-   * If parent stream is a python stream, we can't call partition related methods
-   * in the java stream.
+   * If parent stream is a python stream, we can't call partition related methods in the java
+   * stream.
    */
   private void checkPartitionCall() {
     if (getInputStream() != null && getInputStream().getLanguage() == Language.JAVA) {
@@ -189,9 +192,9 @@ public class PythonDataStream extends Stream<PythonDataStream, Object> implement
   }
 
   /**
-   * Convert this stream as a java stream.
-   * The converted stream and this stream are the same logical stream, which has same stream id.
-   * Changes in converted stream will be reflected in this stream and vice versa.
+   * Convert this stream as a java stream. The converted stream and this stream are the same logical
+   * stream, which has same stream id. Changes in converted stream will be reflected in this stream
+   * and vice versa.
    */
   public DataStream<Object> asJavaStream() {
     return new DataStream<>(this);

streaming/java/streaming-api/src/main/java/io/ray/streaming/python/stream/PythonKeyDataStream.java

@@ -19,8 +19,8 @@ public class PythonKeyDataStream extends PythonDataStream implements PythonStrea
   }
 
   /**
-   * Create a python stream that reference passed python stream.
-   * Changes in new stream will be reflected in referenced stream and vice versa
+   * Create a python stream that reference passed python stream. Changes in new stream will be
+   * reflected in referenced stream and vice versa
    */
   public PythonKeyDataStream(DataStream referencedStream) {
     super(referencedStream);
@@ -44,9 +44,9 @@ public class PythonKeyDataStream extends PythonDataStream implements PythonStrea
   }
 
   /**
-   * Convert this stream as a java stream.
-   * The converted stream and this stream are the same logical stream, which has same stream id.
-   * Changes in converted stream will be reflected in this stream and vice versa.
+   * Convert this stream as a java stream. The converted stream and this stream are the same logical
+   * stream, which has same stream id. Changes in converted stream will be reflected in this stream
+   * and vice versa.
    */
   public KeyDataStream<Object, Object> asJavaStream() {
     return new KeyDataStream(this);

streaming/java/streaming-api/src/main/java/io/ray/streaming/python/stream/PythonStream.java

@@ -4,4 +4,5 @@ package io.ray.streaming.python.stream;
  * A marker interface used to identify all python streams.
  */
 public interface PythonStream {
+
 }

streaming/java/streaming-api/src/main/java/io/ray/streaming/python/stream/PythonStreamSink.java

@@ -8,6 +8,7 @@ import io.ray.streaming.python.PythonOperator;
  * Represents a sink of the PythonStream.
  */
 public class PythonStreamSink extends StreamSink implements PythonStream {
+
   public PythonStreamSink(PythonDataStream input, PythonOperator sinkOperator) {
     super(input, sinkOperator);
     getStreamingContext().addSink(this);

streaming/java/streaming-api/src/main/java/io/ray/streaming/python/stream/PythonStreamSource.java

@@ -17,8 +17,9 @@ public class PythonStreamSource extends PythonDataStream implements StreamSource
     withChainStrategy(ChainStrategy.HEAD);
   }
 
-  public static PythonStreamSource from(StreamingContext streamingContext,
-                                        PythonFunction sourceFunction) {
+  public static PythonStreamSource from(
+      StreamingContext streamingContext,
+      PythonFunction sourceFunction) {
     sourceFunction.setFunctionInterface(FunctionInterface.SOURCE_FUNCTION);
     return new PythonStreamSource(streamingContext, sourceFunction);
   }

streaming/java/streaming-api/src/main/java/io/ray/streaming/python/stream/PythonUnionStream.java

@@ -6,11 +6,11 @@ import java.util.List;
 
 /**
  * Represents a union DataStream.
- *
  * <p>This stream does not create a physical operation, it only affects how upstream data are
- *  connected to downstream data.
+ * connected to downstream data.
  */
 public class PythonUnionStream extends PythonDataStream {
+
   private List<PythonDataStream> unionStreams;
 
   public PythonUnionStream(PythonDataStream input, List<PythonDataStream> others) {

streaming/java/streaming-api/src/main/java/io/ray/streaming/util/Config.java

@@ -11,7 +11,7 @@ public class Config {
   public static final String MEMORY_CHANNEL = "memory_channel";
   public static final String NATIVE_CHANNEL = "native_channel";
   public static final String CHANNEL_SIZE = "channel_size";
-  public static final String CHANNEL_SIZE_DEFAULT = String.valueOf((long)Math.pow(10, 8));
+  public static final String CHANNEL_SIZE_DEFAULT = String.valueOf((long) Math.pow(10, 8));
   public static final String IS_RECREATE = "streaming.is_recreate";
   // return from DataReader.getBundle if only empty message read in this interval.
   public static final String TIMER_INTERVAL_MS = "timer_interval_ms";

streaming/java/streaming-api/src/test/java/io/ray/streaming/api/stream/StreamTest.java

@@ -2,6 +2,7 @@ package io.ray.streaming.api.stream;
 
 import static org.testng.Assert.assertEquals;
 
+
 import io.ray.streaming.api.context.StreamingContext;
 import io.ray.streaming.operator.impl.MapOperator;
 import io.ray.streaming.python.stream.PythonDataStream;

streaming/java/streaming-api/src/test/java/io/ray/streaming/jobgraph/JobGraphOptimizerTest.java

@@ -2,6 +2,7 @@ package io.ray.streaming.jobgraph;
 
 import static org.testng.Assert.assertEquals;
 
+
 import com.google.common.collect.Lists;
 import io.ray.streaming.api.context.StreamingContext;
 import io.ray.streaming.api.stream.DataStream;
@@ -12,13 +13,14 @@ import org.slf4j.LoggerFactory;
 import org.testng.annotations.Test;
 
 public class JobGraphOptimizerTest {
-  private static final Logger LOG = LoggerFactory.getLogger( JobGraphOptimizerTest.class );
+
+  private static final Logger LOG = LoggerFactory.getLogger(JobGraphOptimizerTest.class);
 
   @Test
   public void testOptimize() {
     StreamingContext context = StreamingContext.buildContext();
     DataStream<Integer> source1 = DataStreamSource.fromCollection(context,
-        Lists.newArrayList(1 ,2 ,3));
+        Lists.newArrayList(1, 2, 3));
     DataStream<String> source2 = DataStreamSource.fromCollection(context,
         Lists.newArrayList("1", "2", "3"));
     DataStream<String> source3 = DataStreamSource.fromCollection(context,
@@ -43,7 +45,7 @@ public class JobGraphOptimizerTest {
   public void testOptimizeHybridStream() {
     StreamingContext context = StreamingContext.buildContext();
     DataStream<Integer> source1 = DataStreamSource.fromCollection(context,
-        Lists.newArrayList(1 ,2 ,3));
+        Lists.newArrayList(1, 2, 3));
     DataStream<String> source2 = DataStreamSource.fromCollection(context,
         Lists.newArrayList("1", "2", "3"));
     source1.asPythonStream()