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

Author: ZhangJian He

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;