refact: use standard UTF-8 charset & enhance CI configs

hugegraph-cassandra/src/main/java/org/apache/hugegraph/backend/store/cassandra/CassandraShard.java

@@ -56,12 +56,13 @@
  * CassandraShard is used for cassandra scanning operations.
  * Each shard represents a range of tokens for a node.
  * Reading data from a given shard does not cross multiple nodes.
+ * <p>
  * Refer to AbstractColumnFamilyInputFormat from:
  * <a href="https://github.com/2013Commons/hive-cassandra/">...</a>
  */
 public class CassandraShard {
 
-    /* The minimal shard size should >= 1M to prevent too many number of shards */
+    /** The minimal shard size should >= 1M to prevent too many number of shards */
     private static final int MIN_SHARD_SIZE = (int) Bytes.MB;
 
     private CassandraSessionPool.Session session;
@@ -228,7 +229,7 @@ private static Map<TokenRange, Long> describeSplits(
                                               tokenRange.getEnd().toString());
         Row row = resultSet.one();
 
-        long meanPartitionSize = 0L;
+        long meanPartitionSize;
         long partitionsCount = 0L;
         long splitCount = 0L;
 

hugegraph-core/src/main/java/org/apache/hugegraph/analyzer/AnsjAnalyzer.java

@@ -56,7 +56,7 @@ public AnsjAnalyzer(String mode) {
 
     @Override
     public Set<String> segment(String text) {
-        Result terms = null;
+        Result terms;
         switch (this.analysis) {
             case "BaseAnalysis":
                 terms = BaseAnalysis.parse(text);

hugegraph-core/src/main/java/org/apache/hugegraph/backend/serializer/BytesBuffer.java

@@ -165,11 +165,11 @@ private void require(int size) {
         E.checkState(this.resize, "Can't resize for wrapped buffer");
 
         // Extra capacity as buffer
-        int newcapacity = size + this.buffer.limit() + DEFAULT_CAPACITY;
-        E.checkArgument(newcapacity <= MAX_BUFFER_CAPACITY,
+        int newCapacity = size + this.buffer.limit() + DEFAULT_CAPACITY;
+        E.checkArgument(newCapacity <= MAX_BUFFER_CAPACITY,
                         "Capacity exceeds max buffer capacity: %s",
                         MAX_BUFFER_CAPACITY);
-        ByteBuffer newBuffer = ByteBuffer.allocate(newcapacity);
+        ByteBuffer newBuffer = ByteBuffer.allocate(newCapacity);
         ((Buffer) this.buffer).flip();
         newBuffer.put(this.buffer);
         this.buffer = newBuffer;

hugegraph-core/src/main/java/org/apache/hugegraph/traversal/optimize/HugeScriptTraversal.java

@@ -53,10 +53,8 @@ public final class HugeScriptTraversal<S, E> extends DefaultTraversal<S, E> {
 
     private Object result;
 
-    public HugeScriptTraversal(TraversalSource traversalSource,
-                               String language, String script,
-                               Map<String, Object> bindings,
-                               Map<String, String> aliases) {
+    public HugeScriptTraversal(TraversalSource traversalSource, String language, String script,
+                               Map<String, Object> bindings, Map<String, String> aliases) {
         this.graph = traversalSource.getGraph();
         this.language = language;
         this.script = script;
@@ -75,8 +73,7 @@ public String script() {
 
     @Override
     public void applyStrategies() throws IllegalStateException {
-        ScriptEngine engine =
-                     SingleGremlinScriptEngineManager.get(this.language);
+        ScriptEngine engine = SingleGremlinScriptEngineManager.get(this.language);
 
         Bindings bindings = engine.createBindings();
         bindings.putAll(this.bindings);
@@ -94,9 +91,8 @@ public void applyStrategies() throws IllegalStateException {
         for (Map.Entry<String, String> entry : this.aliases.entrySet()) {
             Object value = bindings.get(entry.getValue());
             if (value == null) {
-                throw new IllegalArgumentException(String.format(
-                          "Invalid aliase '%s':'%s'",
-                          entry.getKey(), entry.getValue()));
+                throw new IllegalArgumentException(String.format("Invalid alias '%s':'%s'",
+                                                                 entry.getKey(), entry.getValue()));
             }
             bindings.put(entry.getKey(), value);
         }
@@ -105,7 +101,7 @@ public void applyStrategies() throws IllegalStateException {
             Object result = engine.eval(this.script, bindings);
 
             if (result instanceof Admin) {
-                @SuppressWarnings({ "unchecked", "resource" })
+                @SuppressWarnings({ "unchecked"})
                 Admin<S, E> traversal = (Admin<S, E>) result;
                 traversal.getSideEffects().mergeInto(this.sideEffects);
                 traversal.getSteps().forEach(this::addStep);

hugegraph-core/src/main/java/org/apache/hugegraph/type/define/Cardinality.java

@@ -39,8 +39,8 @@ public enum Cardinality implements SerialEnum {
      */
     SET(3, "set");
 
-    private byte code = 0;
-    private String name = null;
+    private final byte code;
+    private final String name;
 
     static {
         SerialEnum.register(Cardinality.class);
@@ -78,8 +78,8 @@ public static Cardinality convert(VertexProperty.Cardinality cardinality) {
             case set:
                 return SET;
             default:
-                throw new AssertionError(String.format(
-                          "Unrecognized cardinality: '%s'", cardinality));
+                throw new AssertionError(String.format("Unrecognized cardinality: '%s'",
+                                                       cardinality));
         }
     }
 }

hugegraph-core/src/main/java/org/apache/hugegraph/util/LZ4Util.java

@@ -37,43 +37,36 @@ public static BytesBuffer compress(byte[] bytes, int blockSize) {
         return compress(bytes, blockSize, DEFAULT_BUFFER_RATIO);
     }
 
-    public static BytesBuffer compress(byte[] bytes, int blockSize,
-                                       float bufferRatio) {
+    public static BytesBuffer compress(byte[] bytes, int blockSize, float bufferRatio) {
         float ratio = bufferRatio <= 0.0F ? DEFAULT_BUFFER_RATIO : bufferRatio;
         LZ4Factory factory = LZ4Factory.fastestInstance();
         LZ4Compressor compressor = factory.fastCompressor();
         int initBufferSize = Math.round(bytes.length / ratio);
         BytesBuffer buf = new BytesBuffer(initBufferSize);
-        LZ4BlockOutputStream lz4Output = new LZ4BlockOutputStream(
-                                         buf, blockSize, compressor);
+        LZ4BlockOutputStream lz4Output = new LZ4BlockOutputStream(buf, blockSize, compressor);
         try {
             lz4Output.write(bytes);
             lz4Output.close();
         } catch (IOException e) {
             throw new BackendException("Failed to compress", e);
         }
-        /*
-         * If need to perform reading outside the method,
-         * remember to call forReadWritten()
-         */
+        // If we need to perform reading outside the method, remember to call forReadWritten()
         return buf;
     }
 
     public static BytesBuffer decompress(byte[] bytes, int blockSize) {
         return decompress(bytes, blockSize, DEFAULT_BUFFER_RATIO);
     }
 
-    public static BytesBuffer decompress(byte[] bytes, int blockSize,
-                                         float bufferRatio) {
+    public static BytesBuffer decompress(byte[] bytes, int blockSize, float bufferRatio) {
         float ratio = bufferRatio <= 0.0F ? DEFAULT_BUFFER_RATIO : bufferRatio;
         LZ4Factory factory = LZ4Factory.fastestInstance();
         LZ4FastDecompressor decompressor = factory.fastDecompressor();
         ByteArrayInputStream bais = new ByteArrayInputStream(bytes);
         int initBufferSize = Math.min(Math.round(bytes.length * ratio),
                                       BytesBuffer.MAX_BUFFER_CAPACITY);
         BytesBuffer buf = new BytesBuffer(initBufferSize);
-        LZ4BlockInputStream lzInput = new LZ4BlockInputStream(bais,
-                                                              decompressor);
+        LZ4BlockInputStream lzInput = new LZ4BlockInputStream(bais, decompressor);
         int count;
         byte[] buffer = new byte[blockSize];
         try {
@@ -84,10 +77,7 @@ public static BytesBuffer decompress(byte[] bytes, int blockSize,
         } catch (IOException e) {
             throw new BackendException("Failed to decompress", e);
         }
-        /*
-         * If need to perform reading outside the method,
-         * remember to call forReadWritten()
-         */
+        // If we need to perform reading outside the method, remember to call forReadWritten()
         return buf;
     }
 }

hugegraph-core/src/main/java/org/apache/hugegraph/util/StringEncoding.java

@@ -14,16 +14,17 @@
 
 package org.apache.hugegraph.util;
 
-import java.io.UnsupportedEncodingException;
+import java.io.IOException;
+import java.nio.charset.StandardCharsets;
 import java.security.MessageDigest;
 import java.security.NoSuchAlgorithmException;
 import java.util.Base64;
 import java.util.UUID;
 
-import org.mindrot.jbcrypt.BCrypt;
-
 import org.apache.hugegraph.HugeException;
 import org.apache.hugegraph.backend.serializer.BytesBuffer;
+import org.mindrot.jbcrypt.BCrypt;
+
 import com.google.common.base.CharMatcher;
 
 /**
@@ -49,7 +50,7 @@ public final class StringEncoding {
     private static final Base64.Encoder BASE64_ENCODER = Base64.getEncoder();
     private static final Base64.Decoder BASE64_DECODER = Base64.getDecoder();
 
-    // Similar to {@link StringSerializer}
+    /** Similar to {@link StringSerializer} */
     public static int writeAsciiString(byte[] array, int offset, String value) {
         E.checkArgument(CharMatcher.ascii().matchesAllOf(value),
                         "'%s' must be ASCII string", value);
@@ -65,7 +66,8 @@ public static int writeAsciiString(byte[] array, int offset, String value) {
             assert c <= 127;
             byte b = (byte) c;
             if (++i == len) {
-                b |= 0x80; // End marker
+                // End marker
+                b |= 0x80;
             }
             array[offset++] = b;
         } while (i < len);
@@ -75,7 +77,7 @@ public static int writeAsciiString(byte[] array, int offset, String value) {
 
     public static String readAsciiString(byte[] array, int offset) {
         StringBuilder sb = new StringBuilder();
-        int c = 0;
+        int c;
         do {
             c = 0xFF & array[offset++];
             if (c != 0x80) {
@@ -92,33 +94,21 @@ public static int getAsciiByteLength(String value) {
     }
 
     public static byte[] encode(String value) {
-        try {
-            return value.getBytes("UTF-8");
-        } catch (UnsupportedEncodingException e) {
-            throw new HugeException("Failed to encode string", e);
-        }
+        return value.getBytes(StandardCharsets.UTF_8);
     }
 
     public static String decode(byte[] bytes) {
         if (bytes.length == 0) {
             return STRING_EMPTY;
         }
-        try {
-            return new String(bytes, "UTF-8");
-        } catch (UnsupportedEncodingException e) {
-            throw new HugeException("Failed to decode string", e);
-        }
+        return new String(bytes, StandardCharsets.UTF_8);
     }
 
     public static String decode(byte[] bytes, int offset, int length) {
         if (length == 0) {
             return STRING_EMPTY;
         }
-        try {
-            return new String(bytes, offset, length, "UTF-8");
-        } catch (UnsupportedEncodingException e) {
-            throw new HugeException("Failed to decode string", e);
-        }
+        return new String(bytes, offset, length, StandardCharsets.UTF_8);
     }
 
     public static String encodeBase64(byte[] bytes) {
@@ -137,26 +127,30 @@ public static byte[] compress(String value) {
     }
 
     public static byte[] compress(String value, float bufferRatio) {
-        BytesBuffer buf = LZ4Util.compress(encode(value), BLOCK_SIZE,
-                                           bufferRatio);
-        return buf.bytes();
+        try (BytesBuffer buf = LZ4Util.compress(encode(value), BLOCK_SIZE, bufferRatio)) {
+            return buf.bytes();
+        } catch (IOException e) {
+            throw new RuntimeException(e);
+        }
     }
 
     public static String decompress(byte[] value) {
         return decompress(value, LZ4Util.DEFAULT_BUFFER_RATIO);
     }
 
     public static String decompress(byte[] value, float bufferRatio) {
-        BytesBuffer buf = LZ4Util.decompress(value, BLOCK_SIZE, bufferRatio);
-        return decode(buf.array(), 0, buf.position());
+        try (BytesBuffer buf = LZ4Util.decompress(value, BLOCK_SIZE, bufferRatio)) {
+            return decode(buf.array(), 0, buf.position());
+        } catch (IOException e) {
+            throw new RuntimeException(e);
+        }
     }
 
     public static String hashPassword(String password) {
         return BCrypt.hashpw(password, BCrypt.gensalt(4));
     }
 
-    public static boolean checkPassword(String candidatePassword,
-                                        String dbPassword) {
+    public static boolean checkPassword(String candidatePassword, String dbPassword) {
         return BCrypt.checkpw(candidatePassword, dbPassword);
     }
 
@@ -177,8 +171,7 @@ public static UUID uuid(String value) {
                 return UUID.fromString(value);
             }
             // UUID represented by hex string
-            E.checkArgument(value.length() == 32,
-                            "Invalid UUID string: %s", value);
+            E.checkArgument(value.length() == 32, "Invalid UUID string: %s", value);
             String high = value.substring(0, 16);
             String low = value.substring(16);
             return new UUID(Long.parseUnsignedLong(high, 16),

hugegraph-test/src/main/java/org/apache/hugegraph/tinkerpop/ProcessBasicSuite.java

@@ -201,7 +201,7 @@ public class ProcessBasicSuite extends AbstractGremlinSuite {
      * A list of the minimum set of base tests that
      * Gremlin flavors should implement to be compliant with Gremlin.
      */
-    private static final Class<?>[] TESTS_TO_ENFORCE = new Class<?>[] {
+    private static final Class<?>[] TESTS_TO_ENFORCE = new Class<?>[]{
         // branch
         BranchTest.class,
         ChooseTest.class,
@@ -267,17 +267,14 @@ public class ProcessBasicSuite extends AbstractGremlinSuite {
     };
 
     public ProcessBasicSuite(final Class<?> klass,
-                             final RunnerBuilder builder)
-                             throws InitializationError {
+                             final RunnerBuilder builder) throws InitializationError {
         super(klass, builder, ALL_TESTS, TESTS_TO_ENFORCE, true,
               TraversalEngine.Type.STANDARD);
         RegisterUtil.registerBackends();
     }
 
-    public ProcessBasicSuite(final Class<?> klass,
-                             final RunnerBuilder builder,
-                             final Class<?>[] testsToExecute)
-                             throws InitializationError {
+    public ProcessBasicSuite(final Class<?> klass, final RunnerBuilder builder,
+                             final Class<?>[] testsToExecute) throws InitializationError {
         super(klass, builder, testsToExecute, TESTS_TO_ENFORCE, true,
               TraversalEngine.Type.STANDARD);
         RegisterUtil.registerBackends();

hugegraph-test/src/main/java/org/apache/hugegraph/tinkerpop/StructureBasicSuite.java

@@ -17,7 +17,7 @@
 
 package org.apache.hugegraph.tinkerpop;
 
-import org.apache.commons.configuration.ConfigurationException;
+import org.apache.hugegraph.dist.RegisterUtil;
 import org.apache.tinkerpop.gremlin.AbstractGremlinSuite;
 import org.apache.tinkerpop.gremlin.GraphManager;
 import org.apache.tinkerpop.gremlin.GraphProvider;
@@ -54,8 +54,6 @@
 import org.junit.runners.model.RunnerBuilder;
 import org.junit.runners.model.Statement;
 
-import org.apache.hugegraph.dist.RegisterUtil;
-
 /**
  * Standard structure test suite for tinkerpop graph
  *
@@ -100,8 +98,7 @@ public class StructureBasicSuite extends AbstractGremlinSuite {
 
     public StructureBasicSuite(final Class<?> klass,
                                final RunnerBuilder builder)
-                               throws InitializationError,
-                                      ConfigurationException {
+                               throws InitializationError {
         super(klass, builder, ALL_TESTS, null, true,
               TraversalEngine.Type.STANDARD);