HDDS-12399. Enable PMD.ForLoopCanBeForeach rule

dev-support/pmd/pmd-ruleset.xml

@@ -26,6 +26,7 @@
     PMD Ruleset for Apache Ozone
   </description>
 
+  <rule ref="category/java/bestpractices.xml/ForLoopCanBeForeach"/>
   <rule ref="category/java/bestpractices.xml/MissingOverride"/>
 
   <exclude-pattern>.*/generated-sources/.*</exclude-pattern>

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

@@ -793,8 +793,8 @@ public void testFailedLocationsAreNotRead() throws IOException {
 
       // Read full stripe
       int read = ecb.read(bufs);
-      for (int j = 0; j < bufs.length; j++) {
-        ECStreamTestUtil.assertBufferMatches(bufs[j], dataGen);
+      for (ByteBuffer buffer : bufs) {
+        ECStreamTestUtil.assertBufferMatches(buffer, dataGen);
       }
       assertEquals(stripeSize(), read);
 

hadoop-hdds/common/src/main/java/org/apache/hadoop/hdds/scm/net/NodeSchemaLoader.java

@@ -390,12 +390,13 @@ private NodeSchemaLoadResult loadTopologySection(Element root,
             throw new IllegalArgumentException("Topology path depth doesn't "
                 + "match layer element numbers");
           }
-          for (int j = 0; j < layerIDs.length; j++) {
-            if (schemas.get(layerIDs[j]) == null) {
-              throw new IllegalArgumentException("No layer found for id " +
-                  layerIDs[j]);
+
+          for (String layerID : layerIDs) {
+            if (schemas.get(layerID) == null) {
+              throw new IllegalArgumentException("No layer found for id " + layerID);
             }
           }
+
           if (schemas.get(layerIDs[0]).getType() != LayerType.ROOT) {
             throw new IllegalArgumentException("Topology path doesn't start "
                 + "with ROOT layer");
@@ -405,8 +406,9 @@ private NodeSchemaLoadResult loadTopologySection(Element root,
             throw new IllegalArgumentException("Topology path doesn't end "
                 + "with LEAF layer");
           }
-          for (int j = 0; j < layerIDs.length; j++) {
-            schemaList.add(schemas.get(layerIDs[j]));
+
+          for (String layerID : layerIDs) {
+            schemaList.add(schemas.get(layerID));
           }
         } else if (TOPOLOGY_ENFORCE_PREFIX.equalsIgnoreCase(tagName)) {
           enforcePrefix = Boolean.parseBoolean(value);

hadoop-hdds/common/src/main/java/org/apache/hadoop/hdds/scm/pipeline/Pipeline.java

@@ -411,10 +411,10 @@ public HddsProtos.Pipeline getProtobufMessage(int clientVersion, Set<DatanodeDet
     // To save the message size on wire, only transfer the node order based on
     // network topology
     if (!nodesInOrder.isEmpty()) {
-      for (int i = 0; i < nodesInOrder.size(); i++) {
+      for (DatanodeDetails datanodeDetails : nodesInOrder) {
         Iterator<DatanodeDetails> it = nodeStatus.keySet().iterator();
-        for (int j = 0; j < nodeStatus.keySet().size(); j++) {
-          if (it.next().equals(nodesInOrder.get(i))) {
+        for (int j = 0; j < nodeStatus.size(); j++) {
+          if (it.next().equals(datanodeDetails)) {
             builder.addMemberOrders(j);
             break;
           }
@@ -655,8 +655,7 @@ public Pipeline build() {
 
       if (nodeOrder != null && !nodeOrder.isEmpty()) {
         List<DatanodeDetails> nodesWithOrder = new ArrayList<>();
-        for (int i = 0; i < nodeOrder.size(); i++) {
-          int nodeIndex = nodeOrder.get(i);
+        for (int nodeIndex : nodeOrder) {
           Iterator<DatanodeDetails> it = nodeStatus.keySet().iterator();
           while (it.hasNext() && nodeIndex >= 0) {
             DatanodeDetails node = it.next();

hadoop-hdds/common/src/test/java/org/apache/hadoop/hdds/scm/net/TestNetworkTopologyImpl.java

@@ -93,8 +93,8 @@ void initNetworkTopology(NodeSchema[] schemas, Node[] nodeArray) {
     cluster = new NetworkTopologyImpl(NodeSchemaManager.getInstance(),
         mockedShuffleOperation);
     dataNodes = nodeArray.clone();
-    for (int i = 0; i < dataNodes.length; i++) {
-      cluster.add(dataNodes[i]);
+    for (Node dataNode : dataNodes) {
+      cluster.add(dataNode);
     }
   }
 
@@ -195,8 +195,8 @@ static Stream<Arguments> topologies() {
   void testContains(NodeSchema[] schemas, Node[] nodeArray) {
     initNetworkTopology(schemas, nodeArray);
     Node nodeNotInMap = createDatanode("8.8.8.8", "/d2/r4");
-    for (int i = 0; i < dataNodes.length; i++) {
-      assertTrue(cluster.contains(dataNodes[i]));
+    for (Node dataNode : dataNodes) {
+      assertTrue(cluster.contains(dataNode));
     }
     assertFalse(cluster.contains(nodeNotInMap));
   }
@@ -293,18 +293,20 @@ void testAncestor(NodeSchema[] schemas, Node[] nodeArray) {
   @MethodSource("topologies")
   void testAddRemove(NodeSchema[] schemas, Node[] nodeArray) {
     initNetworkTopology(schemas, nodeArray);
-    for (int i = 0; i < dataNodes.length; i++) {
-      cluster.remove(dataNodes[i]);
+    for (Node dataNode : dataNodes) {
+      cluster.remove(dataNode);
     }
-    for (int i = 0; i < dataNodes.length; i++) {
-      assertFalse(cluster.contains(dataNodes[i]));
+
+    for (Node dataNode : dataNodes) {
+      assertFalse(cluster.contains(dataNode));
     }
     // no leaf nodes
     assertEquals(0, cluster.getNumOfLeafNode(null));
     // no inner nodes
     assertEquals(0, cluster.getNumOfNodes(2));
-    for (int i = 0; i < dataNodes.length; i++) {
-      cluster.add(dataNodes[i]);
+
+    for (Node dataNode : dataNodes) {
+      cluster.add(dataNode);
     }
     // Inner nodes are created automatically
     assertThat(cluster.getNumOfNodes(2)).isPositive();

hadoop-hdds/container-service/src/main/java/org/apache/hadoop/ozone/container/ozoneimpl/OzoneContainer.java

@@ -334,8 +334,8 @@ public void buildContainerSet() throws IOException {
     }
 
     try {
-      for (int i = 0; i < volumeThreads.size(); i++) {
-        volumeThreads.get(i).join();
+      for (Thread volumeThread : volumeThreads) {
+        volumeThread.join();
       }
       try (TableIterator<Long, ? extends Table.KeyValue<Long, String>> itr =
                containerSet.getContainerIdsTable().iterator()) {
@@ -597,20 +597,22 @@ public StorageContainerDatanodeProtocolProtos.NodeReportProto getNodeReport()
     StorageContainerDatanodeProtocolProtos.NodeReportProto.Builder nrb
             = StorageContainerDatanodeProtocolProtos.
             NodeReportProto.newBuilder();
-    for (int i = 0; i < reports.length; i++) {
-      nrb.addStorageReport(reports[i].getProtoBufMessage(config));
+
+    for (StorageLocationReport report : reports) {
+      nrb.addStorageReport(report.getProtoBufMessage(config));
     }
 
     StorageLocationReport[] metaReports = metaVolumeSet.getStorageReport();
-    for (int i = 0; i < metaReports.length; i++) {
-      nrb.addMetadataStorageReport(
-          metaReports[i].getMetadataProtoBufMessage());
+
+    for (StorageLocationReport metaReport : metaReports) {
+      nrb.addMetadataStorageReport(metaReport.getMetadataProtoBufMessage());
     }
 
     if (dbVolumeSet != null) {
       StorageLocationReport[] dbReports = dbVolumeSet.getStorageReport();
-      for (int i = 0; i < dbReports.length; i++) {
-        nrb.addDbStorageReport(dbReports[i].getProtoBufMessage());
+
+      for (StorageLocationReport dbReport : dbReports) {
+        nrb.addDbStorageReport(dbReport.getProtoBufMessage());
       }
     }
 

hadoop-hdds/container-service/src/test/java/org/apache/hadoop/ozone/container/common/impl/TestContainerDeletionChoosingPolicy.java

@@ -193,9 +193,9 @@ public void testTopNOrderedChoosingPolicy(ContainerLayoutVersion layout)
     // the empty deletion blocks container should not be chosen
     int containerCount = 0;
     int c = 0;
-    for (int i = 0; i < numberOfBlocks.size(); i++) {
+    for (Integer numberOfBlock : numberOfBlocks) {
       containerCount++;
-      c = c + numberOfBlocks.get(i);
+      c = c + numberOfBlock;
       if (c >= (numContainers + 1)) {
         break;
       }

hadoop-hdds/container-service/src/test/java/org/apache/hadoop/ozone/container/common/impl/TestContainerPersistence.java

@@ -568,8 +568,8 @@ public void testListContainer(ContainerTestVersionInfo versionInfo)
     List<ContainerData> results = new LinkedList<>();
     while (counter < count) {
       containerSet.listContainer(prevKey, step, results);
-      for (int y = 0; y < results.size(); y++) {
-        testMap.remove(results.get(y).getContainerID());
+      for (ContainerData result : results) {
+        testMap.remove(result.getContainerID());
       }
       counter += step;
       long nextKey = results.get(results.size() - 1).getContainerID();

hadoop-hdds/erasurecode/src/main/java/org/apache/ozone/erasurecode/rawcoder/RSRawDecoder.java

@@ -121,8 +121,7 @@ private void processErasures(int[] erasedIndexes) {
     this.erasureFlags = new boolean[getNumAllUnits()];
     this.numErasedDataUnits = 0;
 
-    for (int i = 0; i < erasedIndexes.length; i++) {
-      int index = erasedIndexes[i];
+    for (int index : erasedIndexes) {
       erasureFlags[index] = true;
       if (index < getNumDataUnits()) {
         numErasedDataUnits++;

hadoop-hdds/erasurecode/src/main/java/org/apache/ozone/erasurecode/rawcoder/util/DumpUtil.java

@@ -76,8 +76,8 @@ public static void dumpMatrix(byte[] matrix,
   public static void dumpChunks(String header, ECChunk[] chunks) {
     System.out.println();
     System.out.println(header);
-    for (int i = 0; i < chunks.length; i++) {
-      dumpChunk(chunks[i]);
+    for (ECChunk chunk : chunks) {
+      dumpChunk(chunk);
     }
     System.out.println();
   }

hadoop-hdds/erasurecode/src/main/java/org/apache/ozone/erasurecode/rawcoder/util/GaloisField.java

@@ -315,11 +315,8 @@ public void solveVandermondeSystem(int[] x, ByteBuffer[] y, int len) {
   public int[] multiply(int[] p, int[] q) {
     int len = p.length + q.length - 1;
     int[] result = new int[len];
-    for (int i = 0; i < len; i++) {
-      result[i] = 0;
-    }
-    for (int i = 0; i < p.length; i++) {
 
+    for (int i = 0; i < p.length; i++) {
       for (int j = 0; j < q.length; j++) {
         result[i + j] = add(result[i + j], multiply(p[i], q[j]));
       }
@@ -381,8 +378,9 @@ public int[] add(int[] p, int[] q) {
   public int substitute(int[] p, int x) {
     int result = 0;
     int y = 1;
-    for (int i = 0; i < p.length; i++) {
-      result = result ^ mulTable[p[i]][y];
+
+    for (int j : p) {
+      result = result ^ mulTable[j][y];
       y = mulTable[x][y];
     }
     return result;
@@ -398,8 +396,8 @@ public int substitute(int[] p, int x) {
    */
   public void substitute(byte[][] p, byte[] q, int x) {
     int y = 1;
-    for (int i = 0; i < p.length; i++) {
-      byte[] pi = p[i];
+
+    for (byte[] pi : p) {
       for (int j = 0; j < pi.length; j++) {
         int pij = pi[j] & 0x000000FF;
         q[j] = (byte) (q[j] ^ mulTable[pij][y]);
@@ -443,8 +441,7 @@ public void substitute(byte[][] p, int[] offsets,
    */
   public void substitute(ByteBuffer[] p, int len, ByteBuffer q, int x) {
     int y = 1, iIdx, oIdx;
-    for (int i = 0; i < p.length; i++) {
-      ByteBuffer pi = p[i];
+    for (ByteBuffer pi : p) {
       int pos = pi != null ? pi.position() : 0;
       int limit = pi != null ? pi.limit() : len;
       for (oIdx = q.position(), iIdx = pos;

hadoop-hdds/erasurecode/src/test/java/org/apache/ozone/erasurecode/DumpUtil.java

@@ -72,8 +72,8 @@ public static void dumpMatrix(byte[] matrix,
   public static void dumpChunks(String header, ECChunk[] chunks) {
     System.out.println();
     System.out.println(header);
-    for (int i = 0; i < chunks.length; i++) {
-      dumpChunk(chunks[i]);
+    for (ECChunk chunk : chunks) {
+      dumpChunk(chunk);
     }
     System.out.println();
   }

hadoop-hdds/erasurecode/src/test/java/org/apache/ozone/erasurecode/TestCoderBase.java

@@ -172,12 +172,12 @@ protected int[] getErasedIndexesForDecoding() {
 
     int idx = 0;
 
-    for (int i = 0; i < erasedDataIndexes.length; i++) {
-      erasedIndexesForDecoding[idx++] = erasedDataIndexes[i];
+    for (int erasedDataIndex : erasedDataIndexes) {
+      erasedIndexesForDecoding[idx++] = erasedDataIndex;
     }
 
-    for (int i = 0; i < erasedParityIndexes.length; i++) {
-      erasedIndexesForDecoding[idx++] = erasedParityIndexes[i] + numDataUnits;
+    for (int erasedParityIndex : erasedParityIndexes) {
+      erasedIndexesForDecoding[idx++] = erasedParityIndex + numDataUnits;
     }
 
     return erasedIndexesForDecoding;
@@ -223,14 +223,14 @@ protected ECChunk[] backupAndEraseChunks(ECChunk[] dataChunks,
 
     int idx = 0;
 
-    for (int i = 0; i < erasedDataIndexes.length; i++) {
-      toEraseChunks[idx++] = dataChunks[erasedDataIndexes[i]];
-      dataChunks[erasedDataIndexes[i]] = null;
+    for (int erasedDataIndex : erasedDataIndexes) {
+      toEraseChunks[idx++] = dataChunks[erasedDataIndex];
+      dataChunks[erasedDataIndex] = null;
     }
 
-    for (int i = 0; i < erasedParityIndexes.length; i++) {
-      toEraseChunks[idx++] = parityChunks[erasedParityIndexes[i]];
-      parityChunks[erasedParityIndexes[i]] = null;
+    for (int erasedParityIndex : erasedParityIndexes) {
+      toEraseChunks[idx++] = parityChunks[erasedParityIndex];
+      parityChunks[erasedParityIndex] = null;
     }
 
     return toEraseChunks;
@@ -241,23 +241,21 @@ protected ECChunk[] backupAndEraseChunks(ECChunk[] dataChunks,
    * @param chunks
    */
   protected void eraseDataFromChunks(ECChunk[] chunks) {
-    for (int i = 0; i < chunks.length; i++) {
-      chunks[i] = null;
-    }
+    Arrays.fill(chunks, null);
   }
 
   protected void markChunks(ECChunk[] chunks) {
-    for (int i = 0; i < chunks.length; i++) {
-      if (chunks[i] != null) {
-        chunks[i].getBuffer().mark();
+    for (ECChunk chunk : chunks) {
+      if (chunk != null) {
+        chunk.getBuffer().mark();
       }
     }
   }
 
   protected void restoreChunksFromMark(ECChunk[] chunks) {
-    for (int i = 0; i < chunks.length; i++) {
-      if (chunks[i] != null) {
-        chunks[i].getBuffer().reset();
+    for (ECChunk chunk : chunks) {
+      if (chunk != null) {
+        chunk.getBuffer().reset();
       }
     }
   }