fix core-backend checkstyle issue

hugegraph-core/src/main/java/com/baidu/hugegraph/backend/id/EdgeId.java

@@ -38,11 +38,11 @@
 public class EdgeId implements Id {
 
     public static final HugeKeys[] KEYS = new HugeKeys[] {
-            HugeKeys.OWNER_VERTEX,
-            HugeKeys.DIRECTION,
-            HugeKeys.LABEL,
-            HugeKeys.SORT_VALUES,
-            HugeKeys.OTHER_VERTEX
+        HugeKeys.OWNER_VERTEX,
+        HugeKeys.DIRECTION,
+        HugeKeys.LABEL,
+        HugeKeys.SORT_VALUES,
+        HugeKeys.OTHER_VERTEX
     };
 
     private final Id ownerVertexId;

hugegraph-core/src/main/java/com/baidu/hugegraph/backend/query/Condition.java

@@ -54,7 +54,7 @@ public enum ConditionType {
 
     public enum RelationType implements BiPredicate<Object, Object> {
 
-        EQ("==", (v1, v2) -> {return equals(v1, v2); }),
+        EQ("==", (v1, v2) -> { return equals(v1, v2); }),
         GT(">", (v1, v2) -> { return compare(v1, v2) > 0; }),
         GTE(">=", (v1, v2) -> { return compare(v1, v2) >= 0; }),
         LT("<", (v1, v2) -> { return compare(v1, v2) < 0; }),
@@ -390,7 +390,7 @@ public static Condition contains(Id key, Object value) {
     /**
      * Condition defines
      */
-    public static abstract class BinCondition extends Condition {
+    public abstract static class BinCondition extends Condition {
 
         private Condition left;
         private Condition right;

hugegraph-core/src/main/java/com/baidu/hugegraph/backend/query/ConditionQuery.java

@@ -212,7 +212,7 @@ public List<Condition.Relation> relations() {
         return relations;
     }
 
-    public Relation relation(Id key){
+    public Relation relation(Id key) {
         for (Relation r : this.relations()) {
             if (r.key().equals(key)) {
                 return r;
@@ -831,7 +831,7 @@ public boolean checkRangeIndex(HugeElement element, Condition cond) {
         }
 
         private static boolean removeFieldValue(Set<Object> values,
-                                                Object value){
+                                                Object value) {
             for (Object elem : values) {
                 if (numberEquals(elem, value)) {
                     values.remove(elem);

hugegraph-core/src/main/java/com/baidu/hugegraph/backend/query/ConditionQueryFlatten.java

@@ -186,7 +186,8 @@ private static Condition convTextContainsAny2Or(Relation relation) {
         assert relation.relation() == Condition.RelationType.TEXT_CONTAINS_ANY;
         @SuppressWarnings("unchecked")
         Collection<String> words = (Collection<String>) relation.value();
-        Condition cond, conds = null;
+        Condition cond = null;
+        Condition conds = null;
         for (String word : words) {
             assert relation.key() instanceof Id;
             cond = Condition.textContains((Id) relation.key(), word);

hugegraph-core/src/main/java/com/baidu/hugegraph/backend/query/Query.java

@@ -51,7 +51,7 @@ public class Query implements Cloneable {
     public static final long NO_CAPACITY = -1L;
     public static final long DEFAULT_CAPACITY = 800000L; // HugeGraph-777
 
-    private static final ThreadLocal<Long> capacityContext = new ThreadLocal<>();
+    private static final ThreadLocal<Long> CAPACITY_CONTEXT = new ThreadLocal<>();
 
     protected static final Query NONE = new Query(HugeType.UNKNOWN);
 
@@ -558,17 +558,17 @@ public String toString() {
     }
 
     public static long defaultCapacity(long capacity) {
-        Long old = capacityContext.get();
-        capacityContext.set(capacity);
+        Long old = CAPACITY_CONTEXT.get();
+        CAPACITY_CONTEXT.set(capacity);
         return old != null ? old : DEFAULT_CAPACITY;
     }
 
     public static long defaultCapacity() {
-        Long capacity = capacityContext.get();
+        Long capacity = CAPACITY_CONTEXT.get();
         return capacity != null ? capacity : DEFAULT_CAPACITY;
     }
 
-    public final static void checkForceCapacity(long count)
+    public static final void checkForceCapacity(long count)
                                                 throws LimitExceedException {
         if (count > Query.DEFAULT_CAPACITY) {
             throw new LimitExceedException(

hugegraph-core/src/main/java/com/baidu/hugegraph/backend/serializer/BinaryEntryIterator.java

@@ -129,7 +129,7 @@ private void removeLastRecord() {
         ((BinaryBackendEntry) this.current).removeColumn(lastOne);
     }
 
-    public final static long sizeOfEntry(BackendEntry entry) {
+    public static final long sizeOfEntry(BackendEntry entry) {
         /*
          * 3 cases:
          *  1) one vertex per entry

hugegraph-core/src/main/java/com/baidu/hugegraph/backend/serializer/BinarySerializer.java

@@ -301,7 +301,6 @@ protected void parseEdge(BackendColumn col, HugeVertex vertex,
         }
     }
 
-
     protected void parseVertex(byte[] value, HugeVertex vertex) {
         BytesBuffer buffer = BytesBuffer.wrap(value);
 
@@ -871,9 +870,9 @@ public BackendEntry parse(BackendEntry originEntry) {
         BytesBuffer buffer = BytesBuffer.allocate(BytesBuffer.BUF_EDGE_ID);
         buffer.write(parsedEntry.id().asBytes());
         buffer.write(bytes);
-        parsedEntry = new BinaryBackendEntry(originEntry.type(),
-                                             new BinaryId(buffer.bytes(),
-                                                          BytesBuffer.wrap(buffer.bytes()).readEdgeId()));
+        parsedEntry = new BinaryBackendEntry(originEntry.type(), new BinaryId(buffer.bytes(),
+                                                BytesBuffer.wrap(buffer.bytes()).readEdgeId()));
+
         for (BackendEntry.BackendColumn col : originEntry.columns()) {
             parsedEntry.column(buffer.bytes(), col.value);
         }

hugegraph-core/src/main/java/com/baidu/hugegraph/backend/serializer/GraphSerializer.java

@@ -33,19 +33,25 @@
 
 public interface GraphSerializer {
 
-    public BackendEntry writeVertex(HugeVertex vertex);
-    public BackendEntry writeOlapVertex(HugeVertex vertex);
-    public BackendEntry writeVertexProperty(HugeVertexProperty<?> prop);
-    public HugeVertex readVertex(HugeGraph graph, BackendEntry entry);
+    BackendEntry writeVertex(HugeVertex vertex);
 
-    public BackendEntry writeEdge(HugeEdge edge);
-    public BackendEntry writeEdgeProperty(HugeEdgeProperty<?> prop);
-    public HugeEdge readEdge(HugeGraph graph, BackendEntry entry);
+    BackendEntry writeOlapVertex(HugeVertex vertex);
 
-    public BackendEntry writeIndex(HugeIndex index);
-    public HugeIndex readIndex(HugeGraph graph, ConditionQuery query,
-                               BackendEntry entry);
+    BackendEntry writeVertexProperty(HugeVertexProperty<?> prop);
 
-    public BackendEntry writeId(HugeType type, Id id);
-    public Query writeQuery(Query query);
+    HugeVertex readVertex(HugeGraph graph, BackendEntry entry);
+
+    BackendEntry writeEdge(HugeEdge edge);
+
+    BackendEntry writeEdgeProperty(HugeEdgeProperty<?> prop);
+
+    HugeEdge readEdge(HugeGraph graph, BackendEntry entry);
+
+    BackendEntry writeIndex(HugeIndex index);
+
+    HugeIndex readIndex(HugeGraph graph, ConditionQuery query, BackendEntry entry);
+
+    BackendEntry writeId(HugeType type, Id id);
+
+    Query writeQuery(Query query);
 }

hugegraph-core/src/main/java/com/baidu/hugegraph/backend/serializer/SchemaSerializer.java

@@ -28,15 +28,19 @@
 
 public interface SchemaSerializer {
 
-    public BackendEntry writeVertexLabel(VertexLabel vertexLabel);
-    public VertexLabel readVertexLabel(HugeGraph graph, BackendEntry entry);
+    BackendEntry writeVertexLabel(VertexLabel vertexLabel);
 
-    public BackendEntry writeEdgeLabel(EdgeLabel edgeLabel);
-    public EdgeLabel readEdgeLabel(HugeGraph graph, BackendEntry entry);
+    VertexLabel readVertexLabel(HugeGraph graph, BackendEntry entry);
 
-    public BackendEntry writePropertyKey(PropertyKey propertyKey);
-    public PropertyKey readPropertyKey(HugeGraph graph, BackendEntry entry);
+    BackendEntry writeEdgeLabel(EdgeLabel edgeLabel);
 
-    public BackendEntry writeIndexLabel(IndexLabel indexLabel);
-    public IndexLabel readIndexLabel(HugeGraph graph, BackendEntry entry);
+    EdgeLabel readEdgeLabel(HugeGraph graph, BackendEntry entry);
+
+    BackendEntry writePropertyKey(PropertyKey propertyKey);
+
+    PropertyKey readPropertyKey(HugeGraph graph, BackendEntry entry);
+
+    BackendEntry writeIndexLabel(IndexLabel indexLabel);
+
+    IndexLabel readIndexLabel(HugeGraph graph, BackendEntry entry);
 }

hugegraph-core/src/main/java/com/baidu/hugegraph/backend/store/BackendEntry.java

@@ -33,7 +33,7 @@
 
 public interface BackendEntry extends Idfiable {
 
-    public static class BackendColumn implements Comparable<BackendColumn> {
+    class BackendColumn implements Comparable<BackendColumn> {
 
         public byte[] name;
         public byte[] value;
@@ -71,63 +71,64 @@ public boolean equals(Object obj) {
         }
     }
 
-    public HugeType type();
+    HugeType type();
 
     @Override
-    public Id id();
+    Id id();
 
-    public Id originId();
+    Id originId();
 
-    public Id subId();
+    Id subId();
 
-    public long ttl();
+    long ttl();
 
-    public int columnsSize();
-    public Collection<BackendColumn> columns();
+    int columnsSize();
 
-    public void columns(Collection<BackendColumn> columns);
-    public void columns(BackendColumn column);
+    Collection<BackendColumn> columns();
 
-    public void merge(BackendEntry other);
-    public boolean mergeable(BackendEntry other);
+    void columns(Collection<BackendColumn> columns);
 
-    public void clear();
+    void columns(BackendColumn column);
 
-    public default boolean belongToMe(BackendColumn column) {
+    void merge(BackendEntry other);
+
+    boolean mergeable(BackendEntry other);
+
+    void clear();
+
+    default boolean belongToMe(BackendColumn column) {
         return Bytes.prefixWith(column.name, id().asBytes());
     }
 
-    public default boolean olap() {
+    default boolean olap() {
         return false;
     }
 
-    public interface BackendIterator<T> extends Iterator<T>, AutoCloseable {
+    interface BackendIterator<T> extends Iterator<T>, AutoCloseable {
 
         @Override
-        public void close();
+        void close();
 
-        public byte[] position();
+        byte[] position();
     }
 
-    public interface BackendColumnIterator
-           extends BackendIterator<BackendColumn> {
+    interface BackendColumnIterator extends BackendIterator<BackendColumn> {
 
-        public static BackendColumnIterator empty() {
+        static BackendColumnIterator empty() {
             return EMPTY;
         }
 
-        public static BackendColumnIterator iterator(BackendColumn element) {
+        static BackendColumnIterator iterator(BackendColumn element) {
             return new OneColumnIterator(element);
         }
 
-        public static BackendColumnIterator wrap(Iterator<BackendColumn> iter) {
+        static BackendColumnIterator wrap(Iterator<BackendColumn> iter) {
             return new BackendColumnIteratorWrapper(iter);
         }
 
-        public static final BackendColumnIterator EMPTY = new EmptyIterator();
+        BackendColumnIterator EMPTY = new EmptyIterator();
 
-        public static final class EmptyIterator
-                            implements BackendColumnIterator {
+        final class EmptyIterator implements BackendColumnIterator {
 
             @Override
             public boolean hasNext() {
@@ -150,8 +151,7 @@ public byte[] position() {
             }
         }
 
-        public static final class OneColumnIterator
-                            implements BackendColumnIterator {
+        final class OneColumnIterator implements BackendColumnIterator {
 
             private BackendColumn element;
 
@@ -186,8 +186,7 @@ public byte[] position() {
             }
         }
 
-        public static final class BackendColumnIteratorWrapper
-                            implements BackendColumnIterator {
+        final class BackendColumnIteratorWrapper implements BackendColumnIterator {
 
             private final Iterator<BackendColumn> iter;
 

hugegraph-core/src/main/java/com/baidu/hugegraph/backend/store/BackendSession.java

@@ -26,34 +26,39 @@
  */
 public interface BackendSession {
 
-    public void open();
-    public void close();
+    void open();
 
-    public boolean opened();
-    public boolean closed();
+    void close();
 
-    public Object commit();
+    boolean opened();
 
-    public void rollback();
+    boolean closed();
 
-    public boolean hasChanges();
+    Object commit();
 
-    public int attach();
-    public int detach();
+    void rollback();
 
-    public long created();
-    public long updated();
-    public void update();
+    boolean hasChanges();
 
-    public default void reconnectIfNeeded() {
+    int attach();
+
+    int detach();
+
+    long created();
+
+    long updated();
+
+    void update();
+
+    default void reconnectIfNeeded() {
         // pass
     }
 
-    public default void reset() {
+    default void reset() {
         // pass
     }
 
-    public abstract class AbstractBackendSession implements BackendSession {
+    abstract class AbstractBackendSession implements BackendSession {
 
         protected boolean opened;
         private int refs;