HDDS-14918. Enable PMD rules StringToString, UseArraysAsList and UseIndexOfChar

dev-support/pmd/pmd-ruleset.xml

@@ -42,6 +42,9 @@
   <rule ref="category/java/performance.xml/InefficientEmptyStringCheck"/>
   <rule ref="category/java/performance.xml/InefficientStringBuffering"/>
   <rule ref="category/java/performance.xml/StringInstantiation"/>
+  <rule ref="category/java/performance.xml/StringToString"/>
+  <rule ref="category/java/performance.xml/UseArraysAsList"/>
+  <rule ref="category/java/performance.xml/UseIndexOfChar"/>
   <rule ref="category/java/performance.xml/UseStringBufferLength"/>
 
   <rule ref="category/java/codestyle.xml/FieldDeclarationsShouldBeAtStartOfClass">

hadoop-hdds/client/src/test/java/org/apache/hadoop/ozone/client/io/TestECBlockReconstructedInputStream.java

@@ -24,6 +24,7 @@
 import java.io.IOException;
 import java.nio.ByteBuffer;
 import java.util.ArrayList;
+import java.util.Arrays;
 import java.util.List;
 import java.util.Map;
 import java.util.SplittableRandom;
@@ -363,13 +364,8 @@ private ByteBuffer[] allocateBuffers(int num, int size) {
   }
 
   private void addDataStreamsToFactory(ByteBuffer[] data, ByteBuffer[] parity) {
-    List<ByteBuffer> dataStreams = new ArrayList<>();
-    for (ByteBuffer b : data) {
-      dataStreams.add(b);
-    }
-    for (ByteBuffer b : parity) {
-      dataStreams.add(b);
-    }
+    List<ByteBuffer> dataStreams = new ArrayList<>(Arrays.asList(data));
+    dataStreams.addAll(Arrays.asList(parity));
     streamFactory.setBlockStreamData(dataStreams);
   }
 }

hadoop-hdds/client/src/test/java/org/apache/hadoop/ozone/client/io/TestECBlockReconstructedStripeInputStream.java

@@ -817,13 +817,8 @@ private ECBlockReconstructedStripeInputStream createInputStream(
   }
 
   private void addDataStreamsToFactory(ByteBuffer[] data, ByteBuffer[] parity) {
-    List<ByteBuffer> dataStreams = new ArrayList<>();
-    for (ByteBuffer b : data) {
-      dataStreams.add(b);
-    }
-    for (ByteBuffer b : parity) {
-      dataStreams.add(b);
-    }
+    List<ByteBuffer> dataStreams = new ArrayList<>(Arrays.asList(data));
+    dataStreams.addAll(Arrays.asList(parity));
     streamFactory.setBlockStreamData(dataStreams);
   }
 

hadoop-hdds/container-service/src/main/java/org/apache/hadoop/ozone/container/common/impl/ContainerDataYaml.java

@@ -294,8 +294,7 @@ public Object construct(Node node) {
     private class ConstructLong extends AbstractConstruct {
       @Override
       public Object construct(Node node) {
-        String value = constructScalar((ScalarNode) node).toString()
-            .replaceAll("_", "");
+        String value = constructScalar((ScalarNode) node).replaceAll("_", "");
         int sign = +1;
         char first = value.charAt(0);
         if (first == '-') {

hadoop-hdds/framework/src/main/java/org/apache/hadoop/hdds/server/http/ProfileServlet.java

@@ -166,9 +166,9 @@ private Integer getPid() {
     if (StringUtils.isBlank(pidStr)) {
       String name = ManagementFactory.getRuntimeMXBean().getName();
       if (name != null) {
-        int idx = name.indexOf("@");
+        int idx = name.indexOf('@');
         if (idx != -1) {
-          pidStr = name.substring(0, name.indexOf("@"));
+          pidStr = name.substring(0, idx);
         }
       }
     }

hadoop-hdds/server-scm/src/main/java/org/apache/hadoop/hdds/scm/FetchMetrics.java

@@ -133,7 +133,7 @@ private void writeAttribute(JsonGenerator jg, ObjectName oname, MBeanAttributeIn
     if (attr.isReadable()) {
       String attName = attr.getName();
       if (!"modelerType".equals(attName)) {
-        if (attName.indexOf("=") < 0 && attName.indexOf(":") < 0 && attName.indexOf(" ") < 0) {
+        if (attName.indexOf('=') < 0 && attName.indexOf(':') < 0 && attName.indexOf(' ') < 0) {
           Object value = null;
 
           try {

hadoop-ozone/cli-admin/src/main/java/org/apache/hadoop/ozone/admin/nssummary/NSSummaryCLIUtils.java

@@ -144,7 +144,7 @@ public static String parseInputPath(String path) {
     if (!path.startsWith("ofs://")) {
       return path;
     }
-    int idx = path.indexOf("/", OFS_PREFIX.length());
+    int idx = path.indexOf('/', OFS_PREFIX.length());
     if (idx == -1) {
       return path.substring(OFS_PREFIX.length());
     }

hadoop-ozone/cli-admin/src/test/java/org/apache/hadoop/hdds/scm/cli/datanode/TestListInfoSubcommand.java

@@ -182,7 +182,7 @@ public void testDataNodeByUuidOutput()
     Matcher m = p.matcher(outContent.toString(DEFAULT_ENCODING));
     assertTrue(m.find());
 
-    p = Pattern.compile(nodes.get(0).getNodeID().getUuid().toString(),
+    p = Pattern.compile(nodes.get(0).getNodeID().getUuid(),
         Pattern.MULTILINE);
     m = p.matcher(outContent.toString(DEFAULT_ENCODING));
     assertTrue(m.find());

hadoop-ozone/cli-shell/src/main/java/org/apache/hadoop/ozone/shell/keys/DeleteKeyHandler.java

@@ -115,9 +115,9 @@ private void deleteFSOKey(OzoneBucket bucket, String keyName)
       Path userTrash = new Path(trashRoot, username);
       Path userTrashCurrent = new Path(userTrash, CURRENT);
 
-      String trashDirectory = (keyName.contains("/")
-          ? new Path(userTrashCurrent, keyName.substring(0,
-          keyName.lastIndexOf("/")))
+      int lastDelimiterIndex = keyName.lastIndexOf('/');
+      String trashDirectory = (lastDelimiterIndex >= 0
+          ? new Path(userTrashCurrent, keyName.substring(0, lastDelimiterIndex))
           : userTrashCurrent).toUri().getPath();
 
       String toKeyName = new Path(userTrashCurrent, keyName).toUri().getPath();

hadoop-ozone/common/src/main/java/org/apache/hadoop/ozone/OzoneAcl.java

@@ -181,10 +181,10 @@ public static OzoneAcl parseAcl(String acl)
 
     // Check if acl string contains scope info.
     if (parts[2].matches(ACL_SCOPE_REGEX)) {
-      int indexOfOpenBracket = parts[2].indexOf("[");
+      int indexOfOpenBracket = parts[2].indexOf('[');
       bits = parts[2].substring(0, indexOfOpenBracket);
       aclScope = AclScope.valueOf(parts[2].substring(indexOfOpenBracket + 1,
-          parts[2].indexOf("]")));
+          parts[2].indexOf(']')));
     }
 
     EnumSet<ACLType> acls = EnumSet.noneOf(ACLType.class);

hadoop-ozone/common/src/main/java/org/apache/hadoop/ozone/om/protocolPB/GrpcOmTransport.java

@@ -222,7 +222,7 @@ private Exception unwrapException(Exception ex) {
         // exception potentially generated by OzoneManagerServiceGrpc
         Class<?> realClass = Class.forName(status.getDescription()
             .substring(0, status.getDescription()
-                .indexOf(":")));
+                .indexOf(':')));
         Class<? extends Exception> cls = realClass
             .asSubclass(Exception.class);
         Constructor<? extends Exception> cn = cls.getConstructor(String.class);
@@ -231,9 +231,10 @@ private Exception unwrapException(Exception ex) {
         IOException remote = null;
         try {
           String cause = status.getDescription();
-          cause = cause.substring(cause.indexOf(":") + 2);
-          remote = new RemoteException(cause.substring(0, cause.indexOf(":")),
-              cause.substring(cause.indexOf(":") + 1));
+          int colonIndex = cause.indexOf(':');
+          cause = cause.substring(colonIndex + 2);
+          remote = new RemoteException(cause.substring(0, colonIndex),
+              cause.substring(colonIndex + 1));
           grpcException.initCause(remote);
         } catch (Exception e) {
           LOG.error("cannot get cause for remote exception");

hadoop-ozone/integration-test/src/test/java/org/apache/hadoop/fs/ozone/AbstractRootedOzoneFileSystemTest.java

@@ -776,6 +776,7 @@ void testListStatusRootAndVolumeNonRecursive() throws Exception {
    * Helper function to do FileSystem#listStatus recursively.
    * Simulate what FsShell does, using DFS.
    */
+  @SuppressWarnings("PMD.UseArraysAsList")
   private void listStatusRecursiveHelper(Path curPath, List<FileStatus> result)
       throws IOException {
     FileStatus[] startList = fs.listStatus(curPath);

hadoop-ozone/integration-test/src/test/java/org/apache/hadoop/ozone/om/TestOMDbCheckpointServletInodeBasedXfer.java

@@ -987,7 +987,7 @@ public static Map<String, List<String>> readFileToMap(String filePath) throws IO
         if (!trimmedLine.contains("\t")) {
           continue;
         }
-        int tabIndex = trimmedLine.indexOf("\t");
+        int tabIndex = trimmedLine.indexOf('\t');
         if (tabIndex > 0) {
           // value is the full path that needs to be constructed
           String value = trimmedLine.substring(0, tabIndex).trim();

hadoop-ozone/ozone-manager/src/main/java/org/apache/hadoop/ozone/om/OzoneManager.java

@@ -903,7 +903,7 @@ private void logVersionMismatch(OzoneConfiguration conf, ScmInfo scmInfo) {
     String scmBlockAddress = scmBlockAddressBuilder.toString();
     if (!StringUtils.isBlank(scmBlockAddress)) {
       scmBlockAddress = scmBlockAddress.substring(0,
-          scmBlockAddress.lastIndexOf(","));
+          scmBlockAddress.lastIndexOf(','));
     }
     if (!scmInfo.getClusterId().equals(omStorage.getClusterID())) {
       LOG.error("clusterId from {} is {}, but is {} in {}",

hadoop-ozone/ozonefs-common/src/main/java/org/apache/hadoop/fs/ozone/BasicOzoneFileSystem.java

@@ -478,8 +478,7 @@ public boolean rename(Path src, Path dst) throws IOException {
     }
 
     if (srcStatus.isDirectory()) {
-      if (dstPath.toString()
-          .startsWith(srcPath.toString() + OZONE_URI_DELIMITER)) {
+      if (dstPath.startsWith(srcPath + OZONE_URI_DELIMITER)) {
         LOG.trace("Cannot rename a directory to a subdirectory of self");
         return false;
       }

hadoop-ozone/s3gateway/src/main/java/org/apache/hadoop/ozone/s3/VirtualHostStyleFilter.java

@@ -144,8 +144,9 @@ private String getDomainName(String host) {
   }
 
   private String checkHostWithoutPort(String host) {
-    if (host.contains(":")) {
-      return host.substring(0, host.lastIndexOf(":"));
+    int portIndex = host.lastIndexOf(':');
+    if (portIndex >= 0) {
+      return host.substring(0, portIndex);
     } else {
       return host;
     }

hadoop-ozone/s3gateway/src/test/java/org/apache/hadoop/ozone/s3/TestVirtualHostStyleFilter.java

@@ -47,7 +47,7 @@ public void setup() {
     conf = new OzoneConfiguration();
     s3HttpAddr = "localhost:9878";
     conf.set(S3GatewayConfigKeys.OZONE_S3G_HTTP_ADDRESS_KEY, s3HttpAddr);
-    s3HttpAddr = s3HttpAddr.substring(0, s3HttpAddr.lastIndexOf(":"));
+    s3HttpAddr = s3HttpAddr.substring(0, s3HttpAddr.lastIndexOf(':'));
     conf.set(S3GatewayConfigKeys.OZONE_S3G_DOMAIN_NAME, s3HttpAddr);
   }