[minor] [optimize] Remove redundant toString call (#3254)

bookkeeper-benchmark/src/main/java/org/apache/bookkeeper/benchmark/BenchThroughputLatency.java

@@ -404,7 +404,7 @@ public void process(WatchedEvent event) {
         OutputStream fos = new BufferedOutputStream(new FileOutputStream(latencyFile));
 
         for (Long l: latency) {
-            fos.write((Long.toString(l) + "\t" + (l / 1000000) + "ms\n").getBytes(UTF_8));
+            fos.write((l + "\t" + (l / 1000000) + "ms\n").getBytes(UTF_8));
         }
         fos.flush();
         fos.close();

bookkeeper-common/src/main/java/org/apache/bookkeeper/common/conf/ComponentConfiguration.java

@@ -310,7 +310,7 @@ private Map<String, Object> toMap() {
         Map<String, Object> configMap = new HashMap<>();
         Iterator<String> iterator = this.getKeys();
         while (iterator.hasNext()) {
-            String key = iterator.next().toString();
+            String key = iterator.next();
             Object property = this.getProperty(key);
             if (property != null) {
                 configMap.put(key, property.toString());

bookkeeper-server/src/main/java/org/apache/bookkeeper/bookie/Cookie.java

@@ -167,7 +167,7 @@ public String toString() {
         }
         StringBuilder b = new StringBuilder();
         b.append(CURRENT_COOKIE_LAYOUT_VERSION).append("\n");
-        b.append(builder.build().toString());
+        b.append(builder.build());
         return b.toString();
     }
 

bookkeeper-server/src/main/java/org/apache/bookkeeper/bookie/Journal.java

@@ -1222,7 +1222,7 @@ journalFormatVersionToWrite, getBufferedChannelBuilder(),
             LOG.info("Journal exits when shutting down");
         } finally {
             // There could be packets queued for forceWrite on this logFile
-            // That is fine as this exception is going to anyway take down the
+            // That is fine as this exception is going to anyway take down
             // the bookie. If we execute this as a part of graceful shutdown,
             // close will flush the file system cache making any previous
             // cached writes durable so this is fine as well.
@@ -1277,7 +1277,6 @@ private static int fullRead(JournalChannel fc, ByteBuffer bb) throws IOException
         return total;
     }
 
-    //
     /**
      * Wait for the Journal thread to exit.
      * This is method is needed in order to mock the journal, we can't mock final method of java.lang.Thread class

bookkeeper-server/src/main/java/org/apache/bookkeeper/bookie/JournalChannel.java

@@ -23,12 +23,9 @@
 
 import static java.nio.charset.StandardCharsets.UTF_8;
 
-import com.google.common.annotations.VisibleForTesting;
-
 import java.io.Closeable;
 import java.io.File;
 import java.io.IOException;
-import java.io.RandomAccessFile;
 import java.nio.ByteBuffer;
 import java.nio.channels.FileChannel;
 import java.util.Arrays;
@@ -58,7 +55,7 @@ class JournalChannel implements Closeable {
 
     static final int SECTOR_SIZE = 512;
     private static final int START_OF_FILE = -12345;
-    private static long cacheDropLagBytes = 8 * MB;
+    private static final long cacheDropLagBytes = 8 * MB;
 
     // No header
     static final int V1 = 1;
@@ -71,7 +68,7 @@ class JournalChannel implements Closeable {
     // 1) expanding header to 512
     // 2) Padding writes to align sector size
     static final int V5 = 5;
-    // Adding explicitlac entry
+    // Adding explicit lac entry
     public static final int V6 = 6;
 
     static final int HEADER_SIZE = SECTOR_SIZE; // align header to sector size
@@ -309,12 +306,4 @@ public void forceWrite(boolean forceMetadata) throws IOException {
         }
     }
 
-    @VisibleForTesting
-    public static FileChannel openFileChannel(RandomAccessFile randomAccessFile) {
-        if (randomAccessFile == null) {
-            throw new IllegalArgumentException("Input cannot be null");
-        }
-
-        return randomAccessFile.getChannel();
-    }
 }

bookkeeper-server/src/main/java/org/apache/bookkeeper/conf/AbstractConfiguration.java

@@ -1248,7 +1248,7 @@ private Map<String, Object> toMap() {
         Map<String, Object> configMap = new HashMap<>();
         Iterator<String> iterator = this.getKeys();
         while (iterator.hasNext()) {
-            String key = iterator.next().toString();
+            String key = iterator.next();
             Object property = this.getProperty(key);
             if (property != null) {
                 configMap.put(key, property.toString());

bookkeeper-server/src/main/java/org/apache/bookkeeper/net/AbstractDNSToSwitchMapping.java

@@ -115,7 +115,7 @@ public Map<String, String> getSwitchMap() {
     public String dumpTopology() {
         Map<String, String> rack = getSwitchMap();
         StringBuilder builder = new StringBuilder();
-        builder.append("Mapping: ").append(toString()).append("\n");
+        builder.append("Mapping: ").append(this).append("\n");
         if (rack != null) {
             builder.append("Map:\n");
             Set<String> switches = new HashSet<String>();

bookkeeper-server/src/main/java/org/apache/bookkeeper/net/NetworkTopologyImpl.java

@@ -421,7 +421,7 @@ public void add(Node node) {
             Node rack = getNodeForNetworkLocation(node);
             if (rack != null && !(rack instanceof InnerNode)) {
                 LOG.error("Unexpected data node {} at an illegal network location", node);
-                throw new IllegalArgumentException("Unexpected data node " + node.toString()
+                throw new IllegalArgumentException("Unexpected data node " + node
                         + " at an illegal network location");
             }
             if (clusterMap.add(node)) {
@@ -436,7 +436,7 @@ public void add(Node node) {
                 }
             }
             if (LOG.isDebugEnabled()) {
-                LOG.debug("NetworkTopology became:\n" + this.toString());
+                LOG.debug("NetworkTopology became:\n" + this);
             }
         } finally {
             netlock.writeLock().unlock();
@@ -507,7 +507,7 @@ public void remove(Node node) {
                 }
             }
             if (LOG.isDebugEnabled()) {
-                LOG.debug("NetworkTopology became:\n" + this.toString());
+                LOG.debug("NetworkTopology became:\n" + this);
             }
         } finally {
             netlock.writeLock().unlock();

bookkeeper-server/src/main/java/org/apache/bookkeeper/net/ScriptBasedMapping.java

@@ -210,8 +210,8 @@ public List<String> resolve(List<String> names) {
 
                 if (m.size() != names.size()) {
                     // invalid number of entries returned by the script
-                    LOG.error("Script " + scriptName + " returned " + Integer.toString(m.size()) + " values when "
-                            + Integer.toString(names.size()) + " were expected.");
+                    LOG.error("Script " + scriptName + " returned " + m.size() + " values when "
+                            + names.size() + " were expected.");
                     return null;
                 }
             } else {
@@ -239,8 +239,8 @@ private String runResolveCommand(List<String> args) {
             StringBuilder allOutput = new StringBuilder();
             int numProcessed = 0;
             if (maxArgs < MIN_ALLOWABLE_ARGS) {
-                LOG.warn("Invalid value " + Integer.toString(maxArgs) + " for " + SCRIPT_ARG_COUNT_KEY
-                        + "; must be >= " + Integer.toString(MIN_ALLOWABLE_ARGS));
+                LOG.warn("Invalid value " + maxArgs + " for " + SCRIPT_ARG_COUNT_KEY
+                        + "; must be >= " + MIN_ALLOWABLE_ARGS);
                 return null;
             }
 

bookkeeper-server/src/main/java/org/apache/bookkeeper/sasl/SaslServerState.java

@@ -78,8 +78,7 @@ private SaslServer createSaslServer(final Subject subject, ServerConfiguration s
 
                 final String servicePrincipalNameAndHostname = servicePrincipal.getName();
                 int indexOf = servicePrincipalNameAndHostname.indexOf("/");
-                final String serviceHostnameAndKerbDomain = servicePrincipalNameAndHostname.substring(indexOf + 1,
-                    servicePrincipalNameAndHostname.length());
+                final String serviceHostnameAndKerbDomain = servicePrincipalNameAndHostname.substring(indexOf + 1);
                 int indexOfAt = serviceHostnameAndKerbDomain.indexOf("@");
 
                 final String servicePrincipalName, serviceHostname;

bookkeeper-server/src/main/java/org/apache/bookkeeper/sasl/TGTRefreshThread.java

@@ -162,7 +162,7 @@ public void run() {
                 LOG.info("refreshing now because expiry is before next scheduled refresh time.");
             } else if (now < nextRefresh) {
                 Date until = new Date(nextRefresh);
-                LOG.info("TGT refresh sleeping until: {}", until.toString());
+                LOG.info("TGT refresh sleeping until: {}", until);
                 try {
                     Thread.sleep(nextRefresh - now);
                 } catch (InterruptedException ie) {

bookkeeper-server/src/main/java/org/apache/bookkeeper/server/http/service/DecommissionService.java

@@ -87,7 +87,7 @@ public HttpServiceResponse handle(HttpServiceRequest request) throws Exception {
                     });
 
                     response.setCode(HttpServer.StatusCode.OK);
-                    response.setBody("Success send decommission Bookie command " + bookieSrc.toString());
+                    response.setBody("Success send decommission Bookie command " + bookieSrc);
                     return response;
                 } catch (Exception e) {
                     LOG.error("Exception occurred while decommissioning bookie: ", e);

bookkeeper-server/src/main/java/org/apache/bookkeeper/server/http/service/ListBookiesService.java

@@ -87,7 +87,7 @@ public HttpServiceResponse handle(HttpServiceRequest request) throws Exception {
                     hostname = resolved.getHostName();
                 }
                 output.putIfAbsent(b.toString(), hostname);
-                LOG.debug("bookie: " + b.toString() + " hostname:" + hostname);
+                LOG.debug("bookie: " + b + " hostname:" + hostname);
             }
             String jsonResponse = JsonUtil.toJson(output);
 

bookkeeper-server/src/main/java/org/apache/bookkeeper/tools/cli/commands/autorecovery/LostBookieRecoveryDelayCommand.java

@@ -102,12 +102,12 @@ public boolean handler(ServerConfiguration conf, LBRDFlags flags)
         try {
             if (getter) {
                 int lostBookieRecoveryDelay = admin.getLostBookieRecoveryDelay();
-                LOG.info("LostBookieRecoveryDelay value in ZK: {}", String.valueOf(lostBookieRecoveryDelay));
+                LOG.info("LostBookieRecoveryDelay value in ZK: {}", lostBookieRecoveryDelay);
             } else {
                 int lostBookieRecoveryDelay = flags.set;
                 admin.setLostBookieRecoveryDelay(lostBookieRecoveryDelay);
                 LOG.info("Successfully set LostBookieRecoveryDelay value in ZK: {}",
-                         String.valueOf(lostBookieRecoveryDelay));
+                        lostBookieRecoveryDelay);
             }
         } finally {
             if (admin != null) {

bookkeeper-server/src/main/java/org/apache/bookkeeper/util/DiskChecker.java

@@ -246,21 +246,21 @@ public float checkDir(File dir) throws DiskErrorException,
         float usage = checkDiskFull(dir);
         if (!mkdirsWithExistsCheck(dir)) {
             throw new DiskErrorException("can not create directory: "
-                    + dir.toString());
+                    + dir);
         }
 
         if (!dir.isDirectory()) {
-            throw new DiskErrorException("not a directory: " + dir.toString());
+            throw new DiskErrorException("not a directory: " + dir);
         }
 
         if (!dir.canRead()) {
             throw new DiskErrorException("directory is not readable: "
-                    + dir.toString());
+                    + dir);
         }
 
         if (!dir.canWrite()) {
             throw new DiskErrorException("directory is not writable: "
-                    + dir.toString());
+                    + dir);
         }
         return usage;
     }

bookkeeper-server/src/main/java/org/apache/bookkeeper/util/StringUtils.java

@@ -72,10 +72,10 @@ public static String getShortHierarchicalLedgerPath(long ledgerId) {
         // do 2-4-4 split
         StringBuilder sb = new StringBuilder();
         sb.append("/")
-          .append(ledgerIdStr.substring(0, 2)).append("/")
-          .append(ledgerIdStr.substring(2, 6)).append("/")
+          .append(ledgerIdStr, 0, 2).append("/")
+          .append(ledgerIdStr, 2, 6).append("/")
           .append(LEDGER_NODE_PREFIX)
-          .append(ledgerIdStr.substring(6, 10));
+          .append(ledgerIdStr, 6, 10);
         return sb.toString();
     }
 
@@ -91,12 +91,12 @@ public static String getLongHierarchicalLedgerPath(long ledgerId) {
         // do 3-4-4-4-4 split
         StringBuilder sb = new StringBuilder();
         sb.append("/")
-          .append(ledgerIdStr.substring(0, 3)).append("/")
-          .append(ledgerIdStr.substring(3, 7)).append("/")
-          .append(ledgerIdStr.substring(7, 11)).append("/")
-          .append(ledgerIdStr.substring(11, 15)).append("/")
+          .append(ledgerIdStr, 0, 3).append("/")
+          .append(ledgerIdStr, 3, 7).append("/")
+          .append(ledgerIdStr, 7, 11).append("/")
+          .append(ledgerIdStr, 11, 15).append("/")
           .append(LEDGER_NODE_PREFIX)
-          .append(ledgerIdStr.substring(15, 19));
+          .append(ledgerIdStr, 15, 19);
         return sb.toString();
     }
 

bookkeeper-server/src/main/java/org/apache/bookkeeper/verifier/BookkeeperVerifier.java

@@ -301,7 +301,7 @@ EntryIterator getIterator() {
 
         void openWrite(long entryID) {
             writesInProgress.add(entryID);
-            System.out.format("Open writes, %s%n", writesInProgress.toString());
+            System.out.format("Open writes, %s%n", writesInProgress);
         }
 
         void incReads() {
@@ -382,7 +382,7 @@ private void checkWriteComplete(Consumer<Integer> cb) {
                 System.out.format(
                         "checkWriteComplete: ledger %d, writesInProgress %s%n",
                         ledgerID,
-                        writesInProgress.toString());
+                        writesInProgress);
                 cb.accept(0);
             }
         }
@@ -396,7 +396,7 @@ private void checkOpComplete(Consumer<Integer> cb) {
                 System.out.format(
                         "checkOpComplete: ledger %d, writesInProgress %s, readsInProgress %d%n",
                         ledgerID,
-                        writesInProgress.toString(), readsInProgress);
+                        writesInProgress, readsInProgress);
                 cb.accept(0);
             }
         }

bookkeeper-server/src/test/java/org/apache/bookkeeper/bookie/SkipListArenaTest.java

@@ -190,7 +190,7 @@ public void testConcurrency() throws Exception {
                 }
                 AllocBuffer other = treeMap.put(buf.alloc.getOffset(), buf);
                 if (other != null) {
-                    fail("Buffer " + other.toString() + " overlapped with " + buf.toString());
+                    fail("Buffer " + other + " overlapped with " + buf);
                 }
             }
         }

bookkeeper-server/src/test/java/org/apache/bookkeeper/bookie/storage/ldb/PersistentEntryLogMetadataMapTest.java

@@ -56,7 +56,7 @@ public PersistentEntryLogMetadataMapTest() {
     @Test
     public void simple() throws Exception {
         File tmpDir = tempFolder.newFolder("metadata-cache");
-        String path = tmpDir.getAbsolutePath().toString();
+        String path = tmpDir.getAbsolutePath();
         PersistentEntryLogMetadataMap entryMetadataMap = new PersistentEntryLogMetadataMap(path, configuration);
 
         List<EntryLogMetadata> metadatas = Lists.newArrayList();
@@ -104,7 +104,7 @@ public void simple() throws Exception {
     @Test
     public void closeAndOpen() throws Exception {
         File tmpDir = tempFolder.newFolder();
-        String path = tmpDir.getAbsolutePath().toString();
+        String path = tmpDir.getAbsolutePath();
         PersistentEntryLogMetadataMap entryMetadataMap = new PersistentEntryLogMetadataMap(path, configuration);
 
         List<EntryLogMetadata> metadatas = Lists.newArrayList();

bookkeeper-server/src/test/java/org/apache/bookkeeper/client/BookKeeperDiskSpaceWeightedLedgerPlacementTest.java

@@ -70,7 +70,7 @@ void blockUntilBookieWeightIs(BookieId bookie, Optional<Long> target) throws Int
             }
             fail(String.format(
                     "Server %s still has weight %s rather than %s",
-                    bookie.toString(), freeDiskSpace.toString(), target.toString()));
+                    bookie.toString(), freeDiskSpace, target.toString()));
         }
     }
 

bookkeeper-server/src/test/java/org/apache/bookkeeper/discover/AbstractTestZkRegistrationClient.java

@@ -151,7 +151,7 @@ private void prepareReadBookieServiceInfo(BookieId address, boolean readonly) th
                         Code.NONODE.intValue(),
                         new byte[] {},
                         new Stat());
-            mockZkGetData(regReadonlyPath + "/" + address.toString(),
+            mockZkGetData(regReadonlyPath + "/" + address,
                         zkRegistrationClient.isBookieAddressTracking(),
                         Code.OK.intValue(),
                         new byte[] {},
@@ -162,7 +162,7 @@ private void prepareReadBookieServiceInfo(BookieId address, boolean readonly) th
                         Code.OK.intValue(),
                         new byte[] {},
                         new Stat());
-            mockZkGetData(regReadonlyPath + "/" + address.toString(),
+            mockZkGetData(regReadonlyPath + "/" + address,
                         zkRegistrationClient.isBookieAddressTracking(),
                         Code.NONODE.intValue(),
                         new byte[] {},