fix checkstyle core-util issue

hugegraph-core/src/main/java/com/baidu/hugegraph/traversal/algorithm/HugeTraverser.java

@@ -361,7 +361,7 @@ public static void checkCapacity(long capacity, long access,
     public static void checkSkipDegree(long skipDegree, long degree,
                                        long capacity) {
         E.checkArgument(skipDegree >= 0L &&
-                        skipDegree <= Query.DEFAULT_CAPACITY ,
+                        skipDegree <= Query.DEFAULT_CAPACITY,
                         "The skipped degree must be in [0, %s], but got '%s'",
                         Query.DEFAULT_CAPACITY, skipDegree);
         if (capacity != NO_LIMIT) {
@@ -636,7 +636,7 @@ public String toString() {
 
     public static class PathSet implements Set<Path> {
 
-        public final static PathSet EMPTY = new PathSet(ImmutableSet.of());
+        public static final PathSet EMPTY = new PathSet(ImmutableSet.of());
 
         private final Set<Path> paths;
 

hugegraph-core/src/main/java/com/baidu/hugegraph/traversal/algorithm/JaccardSimilarTraverser.java

@@ -41,7 +41,6 @@ public JaccardSimilarTraverser(HugeGraph graph) {
         super(graph);
     }
 
-
     public double jaccardSimilarity(Id vertex, Id other, Directions dir,
                                     String label, long degree) {
         E.checkNotNull(vertex, "vertex id");

hugegraph-core/src/main/java/com/baidu/hugegraph/traversal/algorithm/OltpTraverser.java

@@ -38,7 +38,6 @@
 import com.baidu.hugegraph.iterator.FilterIterator;
 import com.baidu.hugegraph.util.Consumers;
 
-
 public abstract class OltpTraverser extends HugeTraverser
                                     implements AutoCloseable {
 

hugegraph-core/src/main/java/com/baidu/hugegraph/traversal/algorithm/records/ShortestPathRecords.java

@@ -107,7 +107,7 @@ private Path linkPath(Stack<Record> all, int node) {
         List<Id> ids = new ArrayList<>(size);
         ids.add(this.id(node));
         int value = node;
-        for (int i = size - 1; i > 0 ; i--) {
+        for (int i = size - 1; i > 0; i--) {
             IntMap layer = ((Int2IntRecord) all.elementAt(i)).layer();
             value = layer.get(value);
             ids.add(this.id(value));

hugegraph-core/src/main/java/com/baidu/hugegraph/traversal/optimize/HugeScriptTraversal.java

@@ -25,9 +25,6 @@
 import javax.script.ScriptEngine;
 import javax.script.ScriptException;
 
-import com.baidu.hugegraph.auth.HugePermission;
-import com.baidu.hugegraph.auth.ResourceType;
-import org.apache.tinkerpop.gremlin.groovy.jsr223.GroovyTranslator;
 import org.apache.tinkerpop.gremlin.jsr223.SingleGremlinScriptEngineManager;
 import org.apache.tinkerpop.gremlin.process.traversal.Traversal;
 import org.apache.tinkerpop.gremlin.process.traversal.TraversalSource;

hugegraph-core/src/main/java/com/baidu/hugegraph/traversal/optimize/TraversalUtil.java

@@ -30,7 +30,6 @@
 import java.util.regex.Matcher;
 import java.util.regex.Pattern;
 
-import com.google.common.collect.Collections2;
 import org.apache.tinkerpop.gremlin.process.traversal.Compare;
 import org.apache.tinkerpop.gremlin.process.traversal.Contains;
 import org.apache.tinkerpop.gremlin.process.traversal.Order;
@@ -65,6 +64,7 @@
 import org.apache.tinkerpop.gremlin.structure.PropertyType;
 import org.apache.tinkerpop.gremlin.structure.T;
 import org.apache.tinkerpop.gremlin.structure.Vertex;
+import org.slf4j.Logger;
 
 import com.baidu.hugegraph.HugeException;
 import com.baidu.hugegraph.HugeGraph;
@@ -91,10 +91,13 @@
 import com.baidu.hugegraph.util.DateUtil;
 import com.baidu.hugegraph.util.E;
 import com.baidu.hugegraph.util.JsonUtil;
+import com.baidu.hugegraph.util.Log;
 import com.google.common.collect.ImmutableList;
 
 public final class TraversalUtil {
 
+    private static final Logger LOG = Log.logger(HugeGraph.class);
+
     public static final String P_CALL = "P.";
 
     public static HugeGraph getGraph(Step<?, ?> step) {
@@ -287,9 +290,7 @@ public static void fillConditionQuery(ConditionQuery query,
         }
     }
 
-    public static Condition convHas2Condition(HasContainer has,
-                                              HugeType type,
-                                              HugeGraph graph) {
+    public static Condition convHas2Condition(HasContainer has, HugeType type, HugeGraph graph) {
         P<?> p = has.getPredicate();
         E.checkArgument(p != null, "The predicate of has(%s) is null", has);
         BiPredicate<?, ?> bp = p.getBiPredicate();
@@ -373,7 +374,6 @@ private static Relation convCompare2Relation(HugeGraph graph,
                convCompare2UserpropRelation(graph, type, has);
     }
 
-
     private static Relation convCompare2SyspropRelation(HugeGraph graph,
                                                         HugeType type,
                                                         HasContainer has) {
@@ -397,9 +397,9 @@ private static Relation convCompare2SyspropRelation(HugeGraph graph,
                 return Condition.lte(key, value);
             case neq:
                 return Condition.neq(key, value);
+            default:
+                throw newUnsupportedPredicate(has.getPredicate());
         }
-
-        throw newUnsupportedPredicate(has.getPredicate());
     }
 
     private static Relation convCompare2UserpropRelation(HugeGraph graph,
@@ -426,9 +426,9 @@ private static Relation convCompare2UserpropRelation(HugeGraph graph,
                 return Condition.lte(pkeyId, value);
             case neq:
                 return Condition.neq(pkeyId, value);
+            default:
+                throw newUnsupportedPredicate(has.getPredicate());
         }
-
-        throw newUnsupportedPredicate(has.getPredicate());
     }
 
     private static Condition convRelationType2Relation(HugeGraph graph,
@@ -469,6 +469,8 @@ public static Condition convIn2Relation(HugeGraph graph,
                     return Condition.in(hugeKey, valueList);
                 case without:
                     return Condition.nin(hugeKey, valueList);
+                default:
+                    throw newUnsupportedPredicate(has.getPredicate());
             }
         } else {
             valueList = new ArrayList<>(values);
@@ -480,10 +482,10 @@ public static Condition convIn2Relation(HugeGraph graph,
                     return Condition.in(pkey.id(), valueList);
                 case without:
                     return Condition.nin(pkey.id(), valueList);
+                default:
+                    throw newUnsupportedPredicate(has.getPredicate());
             }
         }
-
-        throw newUnsupportedPredicate(has.getPredicate());
     }
 
     public static Condition convContains2Relation(HugeGraph graph,
@@ -902,7 +904,9 @@ private static Number predicateNumber(String value) {
                         value = JsonUtil.fromJson(value, String.class);
                     }
                     return DateUtil.parse(value).getTime();
-                } catch (Exception ignored) {}
+                } catch (Exception ignored) {
+                    // TODO: improve to throw a exception here
+                }
             }
 
             throw new HugeException(

hugegraph-core/src/main/java/com/baidu/hugegraph/type/HugeType.java

@@ -112,7 +112,7 @@ public boolean isSchema() {
     }
 
     public boolean isGraph() {
-        return this.isVertex() || this.isEdge() ;
+        return this.isVertex() || this.isEdge();
     }
 
     public boolean isVertex() {

hugegraph-core/src/main/java/com/baidu/hugegraph/type/define/SerialEnum.java

@@ -28,33 +28,33 @@
 
 public interface SerialEnum {
 
-    public byte code();
+    byte code();
 
-    static Table<Class<?>, Byte, SerialEnum> table = HashBasedTable.create();
+    Table<Class<?>, Byte, SerialEnum> TABLE = HashBasedTable.create();
 
-    public static void register(Class<? extends SerialEnum> clazz) {
+    static void register(Class<? extends SerialEnum> clazz) {
         Object enums;
         try {
             enums = clazz.getMethod("values").invoke(null);
         } catch (Exception e) {
             throw new BackendException(e);
         }
         for (SerialEnum e : CollectionUtil.<SerialEnum>toList(enums)) {
-            table.put(clazz, e.code(), e);
+            TABLE.put(clazz, e.code(), e);
         }
     }
 
-    public static <T extends SerialEnum> T fromCode(Class<T> clazz, byte code) {
+    static <T extends SerialEnum> T fromCode(Class<T> clazz, byte code) {
         @SuppressWarnings("unchecked")
-        T value = (T) table.get(clazz, code);
+        T value = (T) TABLE.get(clazz, code);
         if (value == null) {
             E.checkArgument(false, "Can't construct %s from code %s",
                             clazz.getSimpleName(), code);
         }
         return value;
     }
 
-    public static void registerInternalEnums() {
+    static void registerInternalEnums() {
         SerialEnum.register(Action.class);
         SerialEnum.register(AggregateType.class);
         SerialEnum.register(Cardinality.class);

hugegraph-core/src/main/java/com/baidu/hugegraph/util/ConfigUtil.java

@@ -58,10 +58,9 @@ public static void checkGremlinConfig(String conf) {
         try {
 
             FileBasedConfigurationBuilder<FileBasedConfiguration> builder =
-            new FileBasedConfigurationBuilder(YAMLConfiguration.class)
+                new FileBasedConfigurationBuilder(YAMLConfiguration.class)
                 .configure(params.fileBased().setFileName(conf));
-            YAMLConfiguration config = (YAMLConfiguration) builder
-                                                           .getConfiguration();
+            YAMLConfiguration config = (YAMLConfiguration) builder.getConfiguration();
 
             List<HierarchicalConfiguration<ImmutableNode>> nodes =
                                            config.childConfigurationsAt(
@@ -78,9 +77,9 @@ public static void checkGremlinConfig(String conf) {
             for (HierarchicalConfiguration<ImmutableNode> node : nodes) {
                 NodeModel<ImmutableNode> nodeModel = node.getNodeModel();
                 E.checkArgument(nodeModel != null &&
-                  (nodeHandler = nodeModel.getNodeHandler()) != null &&
-                  (root = nodeHandler.getRootNode()) != null,
-                  "Node '%s' must contain root", node);
+                    (nodeHandler = nodeModel.getNodeHandler()) != null &&
+                    (root = nodeHandler.getRootNode()) != null,
+                    "Node '%s' must contain root", node);
             }
         } catch (ConfigurationException e) {
             throw new HugeException("Failed to load yaml config file '%s'",

hugegraph-core/src/main/java/com/baidu/hugegraph/util/Consumers.java

@@ -115,7 +115,9 @@ private void run() {
             this.consume();
         }
         assert this.ending;
-        while (this.consume());
+        while (this.consume()){
+            // ignore
+        }
 
         LOG.debug("Worker finished");
     }
@@ -147,7 +149,7 @@ private void done() {
             if (this.exception == null) {
                 this.exception = e;
             } else {
-                LOG.warn("Error while calling done()", e);;
+                LOG.warn("Error while calling done()", e);
             }
         }
     }
@@ -170,7 +172,7 @@ public void provide(V v) throws Throwable {
             try {
                 this.queue.put(v);
             } catch (InterruptedException e) {
-                LOG.warn("Interrupted while enqueue", e);;
+                LOG.warn("Interrupted while enqueue", e);
             }
         }
     }
@@ -262,7 +264,7 @@ public static RuntimeException wrapException(Throwable e) {
 
     public static class ExecutorPool {
 
-        private final static int POOL_CAPACITY = 2 * CoreOptions.CPUS;
+        private static final int POOL_CAPACITY = 2 * CoreOptions.CPUS;
 
         private final String threadNamePrefix;
         private final int executorWorkers;

hugegraph-core/src/main/java/com/baidu/hugegraph/util/GZipUtil.java

@@ -35,7 +35,7 @@ public final class GZipUtil {
 
     private static final int BUF_SIZE = (int) (4 * Bytes.KB);
 
-    public static String md5(String input){
+    public static String md5(String input) {
         return DigestUtils.md5Hex(input);
     }
 

hugegraph-core/src/main/java/com/baidu/hugegraph/util/KryoUtil.java

@@ -32,17 +32,17 @@
 
 public final class KryoUtil {
 
-    private static final ThreadLocal<Kryo> kryos = new ThreadLocal<>();
+    private static final ThreadLocal<Kryo> KRYOS = new ThreadLocal<>();
 
     public static Kryo kryo() {
-        Kryo kryo = kryos.get();
+        Kryo kryo = KRYOS.get();
         if (kryo != null) {
             return kryo;
         }
 
         kryo = new Kryo();
         registerSerializers(kryo);
-        kryos.set(kryo);
+        KRYOS.set(kryo);
         return kryo;
     }
 
@@ -70,9 +70,9 @@ public static byte[] toKryoWithType(Object value) {
             kryo().writeClassAndObject(output, value);
             output.flush();
             return bos.toByteArray();
-       } catch (IOException e) {
-           throw new BackendException("Failed to serialize: %s", e, value);
-       }
+        } catch (IOException e) {
+            throw new BackendException("Failed to serialize: %s", e, value);
+        }
     }
 
     @SuppressWarnings("unchecked")