fix some typo and format some code

fluss-client/src/main/java/com/alibaba/fluss/client/lakehouse/paimon/PaimonBucketAssigner.java

@@ -48,7 +48,7 @@ public PaimonBucketAssigner(RowType rowType, List<String> bucketKey, int bucketN
         this.flussRowWrapper = new FlussRowWrapper();
     }
 
-    private static int[] getBucketKeyIndex(RowType rowType, List<String> bucketKey) {
+    private int[] getBucketKeyIndex(RowType rowType, List<String> bucketKey) {
         int[] bucketKeyIndex = new int[bucketKey.size()];
         for (int i = 0; i < bucketKey.size(); i++) {
             bucketKeyIndex[i] = rowType.getFieldIndex(bucketKey.get(i));

fluss-client/src/main/java/com/alibaba/fluss/client/metrics/ScannerMetricGroup.java

@@ -37,7 +37,8 @@
 /** The metric group for scanner, including {@link LogScanner} and {@link SnapshotScanner}. */
 @Internal
 public class ScannerMetricGroup extends AbstractMetricGroup {
-    private static final String name = "scanner";
+
+    private static final String NAME = "scanner";
     private static final int WINDOW_SIZE = 1024;
 
     private final TablePath tablePath;
@@ -57,7 +58,7 @@ public class ScannerMetricGroup extends AbstractMetricGroup {
     private volatile long pollStartMs;
 
     public ScannerMetricGroup(ClientMetricGroup parent, TablePath tablePath) {
-        super(parent.getMetricRegistry(), makeScope(parent, name), parent);
+        super(parent.getMetricRegistry(), makeScope(parent, NAME), parent);
         this.tablePath = tablePath;
 
         fetchRequestCount = new ThreadSafeSimpleCounter();
@@ -122,7 +123,7 @@ private long lastPollSecondsAgo() {
 
     @Override
     protected String getGroupName(CharacterFilter filter) {
-        return name;
+        return NAME;
     }
 
     @Override

fluss-client/src/main/java/com/alibaba/fluss/client/scanner/log/LogFetcher.java

@@ -87,7 +87,6 @@ public class LogFetcher implements Closeable {
     private final LogRecordReadContext remoteReadContext;
     @Nullable private final Projection projection;
     private final RpcClient rpcClient;
-    private final Configuration conf;
     private final int maxFetchBytes;
     private final int maxBucketFetchBytes;
     private final boolean isCheckCrcs;
@@ -121,7 +120,6 @@ public LogFetcher(
         this.projection = projection;
         this.rpcClient = rpcClient;
         this.logScannerStatus = logScannerStatus;
-        this.conf = conf;
         this.maxFetchBytes = (int) conf.get(ConfigOptions.LOG_FETCH_MAX_BYTES).getBytes();
         this.maxBucketFetchBytes =
                 (int) conf.get(ConfigOptions.LOG_FETCH_MAX_BYTES_FOR_BUCKET).getBytes();

fluss-common/src/main/java/com/alibaba/fluss/fs/FsPath.java

@@ -189,7 +189,7 @@ public FsPath(String pathString) {
         }
 
         // uri path is the rest of the string -- query & fragment not supported
-        final String path = pathString.substring(start, pathString.length());
+        final String path = pathString.substring(start);
 
         initialize(scheme, authority, path);
     }

fluss-common/src/main/java/com/alibaba/fluss/fs/local/LocalFileSystem.java

@@ -134,11 +134,9 @@ public boolean delete(final FsPath f, final boolean recursive) throws IOExceptio
             File[] containedFiles = file.listFiles();
             if (containedFiles == null) {
                 throw new IOException(
-                        "Directory "
-                                + file.toString()
-                                + " does not exist or an I/O error occurred");
+                        "Directory " + file + " does not exist or an I/O error occurred");
             } else if (containedFiles.length != 0) {
-                throw new IOException("Directory " + file.toString() + " is not empty");
+                throw new IOException("Directory " + file + " is not empty");
             }
         }
 

fluss-common/src/main/java/com/alibaba/fluss/row/BinaryString.java

@@ -22,7 +22,6 @@
 import javax.annotation.Nonnull;
 import javax.annotation.Nullable;
 
-import java.io.UnsupportedEncodingException;
 import java.nio.charset.StandardCharsets;
 import java.util.Arrays;
 
@@ -525,7 +524,7 @@ public BinaryString toUpperCase() {
                 // fallback
                 return javaToUpperCase();
             }
-            int upper = Character.toUpperCase((int) b);
+            int upper = Character.toUpperCase(b);
             if (upper > 127) {
                 // fallback
                 return javaToUpperCase();
@@ -559,7 +558,7 @@ public BinaryString toLowerCase() {
                 // fallback
                 return javaToLowerCase();
             }
-            int lower = Character.toLowerCase((int) b);
+            int lower = Character.toLowerCase(b);
             if (lower > 127) {
                 // fallback
                 return javaToLowerCase();
@@ -808,13 +807,9 @@ public static int encodeUTF8(String str, byte[] bytes) {
     }
 
     public static int defaultEncodeUTF8(String str, byte[] bytes) {
-        try {
-            byte[] buffer = str.getBytes("UTF-8");
-            System.arraycopy(buffer, 0, bytes, 0, buffer.length);
-            return buffer.length;
-        } catch (UnsupportedEncodingException e) {
-            throw new RuntimeException("encodeUTF8 error", e);
-        }
+        byte[] buffer = str.getBytes(StandardCharsets.UTF_8);
+        System.arraycopy(buffer, 0, bytes, 0, buffer.length);
+        return buffer.length;
     }
 
     public static String decodeUTF8(byte[] input, int offset, int byteLen) {

fluss-common/src/main/java/com/alibaba/fluss/utils/NetUtils.java

@@ -184,7 +184,7 @@ public static Iterator<Integer> getPortRangeFromString(String rangeDefinition)
             int dashIdx = range.indexOf('-');
             if (dashIdx == -1) {
                 // only one port in range:
-                final int port = Integer.valueOf(range);
+                final int port = Integer.parseInt(range);
                 if (!isValidHostPort(port)) {
                     throw new IllegalConfigurationException(
                             "Invalid port configuration. Port must be between 0"
@@ -195,15 +195,15 @@ public static Iterator<Integer> getPortRangeFromString(String rangeDefinition)
                 rangeIterator = Collections.singleton(Integer.valueOf(range)).iterator();
             } else {
                 // evaluate range
-                final int start = Integer.valueOf(range.substring(0, dashIdx));
+                final int start = Integer.parseInt(range.substring(0, dashIdx));
                 if (!isValidHostPort(start)) {
                     throw new IllegalConfigurationException(
                             "Invalid port configuration. Port must be between 0"
                                     + "and 65535, but was "
                                     + start
                                     + ".");
                 }
-                final int end = Integer.valueOf(range.substring(dashIdx + 1, range.length()));
+                final int end = Integer.parseInt(range.substring(dashIdx + 1));
                 if (!isValidHostPort(end)) {
                     throw new IllegalConfigurationException(
                             "Invalid port configuration. Port must be between 0"

fluss-common/src/main/java/com/alibaba/fluss/utils/UnionIterator.java

@@ -35,7 +35,7 @@ public class UnionIterator<T> implements Iterator<T>, Iterable<T> {
 
     private Iterator<T> currentIterator;
 
-    private ArrayList<Iterator<T>> furtherIterators = new ArrayList<>();
+    private final ArrayList<Iterator<T>> furtherIterators = new ArrayList<>();
 
     private int nextIterator;
 

fluss-common/src/test/java/com/alibaba/fluss/fs/SafetyNetCloseableRegistryTest.java

@@ -254,7 +254,7 @@ void testReaperThreadStartFailed() throws Exception {
 
         try {
             new SafetyNetCloseableRegistry(OutOfMemoryReaperThread::new);
-        } catch (OutOfMemoryError error) {
+        } catch (OutOfMemoryError ignored) {
         }
         assertThat(SafetyNetCloseableRegistry.isReaperThreadRunning()).isFalse();
 

fluss-common/src/test/java/com/alibaba/fluss/record/LogTestBase.java

@@ -80,7 +80,7 @@ protected void assertIndexedLogRecordBatchAndRowEquals(
         LogRecordReadContext readContext =
                 LogRecordReadContext.createIndexedReadContext(rowType, TestData.DEFAULT_SCHEMA_ID);
         try (CloseableIterator<LogRecord> actualIter = actual.records(readContext);
-                CloseableIterator<LogRecord> expectIter = expected.records(readContext); ) {
+                CloseableIterator<LogRecord> expectIter = expected.records(readContext)) {
             int i = 0;
             while (actualIter.hasNext() && expectIter.hasNext()) {
                 DefaultLogRecord actualRecord = (DefaultLogRecord) actualIter.next();

fluss-common/src/test/java/com/alibaba/fluss/row/TestInternalRowGenerator.java

@@ -126,7 +126,7 @@ public static CompactedRow genCompactedRowForAllType() {
         for (int i = 0; i < dataTypes.length; i++) {
             rowEncoder.encodeField(i, fieldGetters[i].getFieldOrNull(indexedRow));
         }
-        return (CompactedRow) rowEncoder.finishRow();
+        return rowEncoder.finishRow();
     }
 
     private static void setRandomNull(

fluss-common/src/test/java/com/alibaba/fluss/row/indexed/IndexedRowTest.java

@@ -160,7 +160,7 @@ void testProjectRow() {
         assertThat(row.getInt(0)).isEqualTo(1000);
         assertThat(row.getString(2)).isEqualTo(BinaryString.fromString("hello"));
 
-        IndexedRow projectRow = (IndexedRow) row.projectRow(new int[] {0, 2});
+        IndexedRow projectRow = row.projectRow(new int[] {0, 2});
         assertThat(projectRow.getInt(0)).isEqualTo(1000);
         assertThat(projectRow.getString(1)).isEqualTo(BinaryString.fromString("hello"));
 

fluss-common/src/test/java/com/alibaba/fluss/testutils/LogRecordBatchAssert.java

@@ -82,7 +82,7 @@ public LogRecordBatchAssert isEqualTo(LogRecordBatch expected) {
                 .isEqualTo(expected.getRecordCount());
         try (LogRecordReadContext readContext = createReadContext(expected.schemaId());
                 CloseableIterator<LogRecord> actualIter = actual.records(readContext);
-                CloseableIterator<LogRecord> expectIter = expected.records(readContext); ) {
+                CloseableIterator<LogRecord> expectIter = expected.records(readContext)) {
             while (expectIter.hasNext()) {
                 assertThat(actualIter.hasNext()).isTrue();
                 assertThatLogRecord(actualIter.next())

fluss-common/src/test/java/com/alibaba/fluss/utils/UnionIteratorTest.java

@@ -50,7 +50,7 @@ void testUnion() {
 
             iter.clear();
             iter.addList(Arrays.asList(1, 2, 3, 4, 5, 6, 7));
-            iter.addList(Collections.<Integer>emptyList());
+            iter.addList(Collections.emptyList());
             iter.addList(Arrays.asList(8, 9, 10, 11));
 
             int val = 1;

fluss-connectors/fluss-connector-flink/src/main/java/com/alibaba/fluss/connector/flink/source/enumerator/initializer/BucketOffsetsRetrieverImpl.java

@@ -52,7 +52,7 @@ public Map<Integer, Long> latestOffsets(
     @Override
     public Map<Integer, Long> earliestOffsets(
             @Nullable String partitionName, Collection<Integer> buckets) {
-        Map<Integer, Long> bucketWithOffset = new HashMap<>();
+        Map<Integer, Long> bucketWithOffset = new HashMap<>(buckets.size());
         for (Integer bucket : buckets) {
             bucketWithOffset.put(bucket, EARLIEST_OFFSET);
         }

fluss-connectors/fluss-connector-flink/src/main/java/com/alibaba/fluss/connector/flink/utils/FlinkConversions.java

@@ -290,9 +290,7 @@ public static org.apache.flink.configuration.ConfigOption<?> toFlinkOption(
             option = builder.stringType().defaultValue(defaultValue);
         } else if (clazz.equals(MemorySize.class)) {
             // use string type in Flink option instead to make convert back easier
-            option =
-                    builder.stringType()
-                            .defaultValue(((MemorySize) flussOption.defaultValue()).toString());
+            option = builder.stringType().defaultValue(flussOption.defaultValue().toString());
         } else if (clazz.isEnum()) {
             //noinspection unchecked
             option =

fluss-filesystems/fluss-fs-hadoop/src/test/java/com/alibaba/fluss/fs/hdfs/HadoopDataInputStreamTest.java

@@ -93,7 +93,7 @@ private static final class SeekableByteArrayInputStream extends InputStream
             implements Seekable, PositionedReadable {
         private final byte[] buffer;
         private int position;
-        private int count;
+        private final int count;
 
         public SeekableByteArrayInputStream(byte[] buffer) {
             this.buffer = buffer;

fluss-lakehouse/fluss-lakehouse-paimon/src/main/java/com/alibaba/fluss/lakehouse/paimon/sink/committer/PaimonStoreMultiCommitter.java

@@ -309,7 +309,7 @@ private void putSnapshotIdAndLogStartOffset(
         }
     }
 
-    Long getLogStartOffset(
+    private Long getLogStartOffset(
             Identifier identifier,
             FileStoreTable fileStoreTable,
             TableBucket tableBucket,
@@ -343,7 +343,7 @@ Long getLogStartOffset(
         return null;
     }
 
-    List<Split> getSplits(
+    private List<Split> getSplits(
             Identifier identifier,
             long snapshotId,
             FileStoreTable fileStoreTable,
@@ -377,9 +377,7 @@ List<Split> getSplits(
     private PaimonAndFlussCommittable toCommittable(
             List<PaimonWrapperManifestCommittable> committables) {
         Map<Identifier, List<ManifestCommittable>> paimonManifestCommittable = new HashMap<>();
-
         Map<Long, Map<TableBucket, Long>> flussLogEndOffsetByTableId = new HashMap<>();
-
         Map<Identifier, Long> tableIdByPaimonIdentifier = new HashMap<>();
         Map<Long, String> partitionNameById = new HashMap<>();
 

fluss-metrics/fluss-metrics-jmx/src/test/java/com/alibaba/fluss/metrics/jmx/JMXServerTest.java

@@ -85,11 +85,10 @@ public interface TestObjectMBean {
 
     /** Test MBean Object. */
     public static class TestObject implements TestObjectMBean {
-        private final int foo = 1;
 
         @Override
         public int getFoo() {
-            return foo;
+            return 1;
         }
     }
 }

fluss-rpc/src/main/java/com/alibaba/fluss/rpc/metrics/ClientMetricGroup.java

@@ -24,18 +24,19 @@
 
 /** The metric group for clients. */
 public class ClientMetricGroup extends AbstractMetricGroup {
-    private static final String name = "client";
+
+    private static final String NAME = "client";
 
     private final String clientId;
 
     public ClientMetricGroup(MetricRegistry registry, String clientId) {
-        super(registry, new String[] {name}, null);
+        super(registry, new String[] {NAME}, null);
         this.clientId = clientId;
     }
 
     @Override
     protected String getGroupName(CharacterFilter filter) {
-        return name;
+        return NAME;
     }
 
     @Override

fluss-rpc/src/main/java/com/alibaba/fluss/rpc/protocol/Errors.java

@@ -175,7 +175,6 @@ public enum Errors {
     INVALID_CONFIG_EXCEPTION(39, "The config is invalid.", InvalidConfigException::new),
     LAKE_STORAGE_NOT_CONFIGURED_EXCEPTION(
             40, "The lake storage is not configured.", LakeStorageNotConfiguredException::new);
-    ;
 
     private static final Logger LOG = LoggerFactory.getLogger(Errors.class);
 

fluss-server/src/main/java/com/alibaba/fluss/server/kv/snapshot/RocksIncrementalSnapshot.java

@@ -164,12 +164,13 @@ private void takeDBNativeSnapshot(@Nonnull File outputDirectory) throws Exceptio
                 Checkpoint snapshot = Checkpoint.create(db)) {
             snapshot.createCheckpoint(outputDirectory.toString());
         } catch (Exception ex) {
+            Exception exception = ex;
             try {
                 FileUtils.deleteDirectory(outputDirectory);
             } catch (IOException cleanupEx) {
-                ex = ExceptionUtils.firstOrSuppressed(cleanupEx, ex);
+                exception = ExceptionUtils.firstOrSuppressed(cleanupEx, exception);
             }
-            throw ex;
+            throw exception;
         }
     }
 

fluss-server/src/main/java/com/alibaba/fluss/server/kv/wal/ArrowWalBuilder.java

@@ -28,11 +28,9 @@
 public class ArrowWalBuilder implements WalBuilder {
 
     private final MemoryLogRecordsArrowBuilder recordsBuilder;
-    private final AbstractPagedOutputView outputView;
 
     public ArrowWalBuilder(int schemaId, ArrowWriter writer, AbstractPagedOutputView outputView) {
         this.recordsBuilder = MemoryLogRecordsArrowBuilder.builder(schemaId, writer, outputView);
-        this.outputView = outputView;
     }
 
     @Override

fluss-server/src/main/java/com/alibaba/fluss/server/metrics/group/CoordinatorMetricGroup.java

@@ -25,23 +25,23 @@
 /** The metric group for coordinator server. */
 public class CoordinatorMetricGroup extends AbstractMetricGroup {
 
-    private static final String name = "coordinator";
+    private static final String NAME = "coordinator";
 
     protected final String clusterId;
     protected final String hostname;
     protected final String serverId;
 
     public CoordinatorMetricGroup(
             MetricRegistry registry, String clusterId, String hostname, String serverId) {
-        super(registry, new String[] {clusterId, hostname, name}, null);
+        super(registry, new String[] {clusterId, hostname, NAME}, null);
         this.clusterId = clusterId;
         this.hostname = hostname;
         this.serverId = serverId;
     }
 
     @Override
     protected String getGroupName(CharacterFilter filter) {
-        return name;
+        return NAME;
     }
 
     @Override

fluss-server/src/main/java/com/alibaba/fluss/server/metrics/group/TabletServerMetricGroup.java

@@ -31,7 +31,7 @@
 /** The metric group for tablet server. */
 public class TabletServerMetricGroup extends AbstractMetricGroup {
 
-    private static final String name = "tabletserver";
+    private static final String NAME = "tabletserver";
 
     private final Map<PhysicalTablePath, PhysicalTableMetricGroup> metricGroupByPhysicalTable =
             new ConcurrentHashMap<>();
@@ -46,7 +46,7 @@ public class TabletServerMetricGroup extends AbstractMetricGroup {
 
     public TabletServerMetricGroup(
             MetricRegistry registry, String clusterId, String hostname, int serverId) {
-        super(registry, new String[] {clusterId, hostname, name}, null);
+        super(registry, new String[] {clusterId, hostname, NAME}, null);
         this.clusterId = clusterId;
         this.hostname = hostname;
         this.serverId = serverId;
@@ -66,7 +66,7 @@ protected final void putVariables(Map<String, String> variables) {
 
     @Override
     protected String getGroupName(CharacterFilter filter) {
-        return name;
+        return NAME;
     }
 
     public Counter replicationBytesIn() {