diff --git a/parquet-hadoop/src/main/java/org/apache/parquet/hadoop/ParquetFileReader.java b/parquet-hadoop/src/main/java/org/apache/parquet/hadoop/ParquetFileReader.java
index 0b1d7405f2..ed4f9ee7ba 100644
--- a/parquet-hadoop/src/main/java/org/apache/parquet/hadoop/ParquetFileReader.java
+++ b/parquet-hadoop/src/main/java/org/apache/parquet/hadoop/ParquetFileReader.java
@@ -408,7 +408,7 @@ static ParquetMetadata readSummaryMetadata(Configuration configuration, Path bas
   }
 
   static List<Footer> footersFromSummaryFile(final Path parent, ParquetMetadata mergedFooters) {
-    Map<Path, ParquetMetadata> footers = new HashMap<Path, ParquetMetadata>();
+    Map<Path, ParquetMetadata> footers = new HashMap<>();
     List<BlockMetaData> blocks = mergedFooters.getBlocks();
     for (BlockMetaData block : blocks) {
       String path = block.getPath();
@@ -452,6 +452,7 @@ public static final ParquetMetadata readFooter(Configuration configuration, Path
    * @deprecated will be removed in 2.0.0;
    *             use {@link ParquetFileReader#open(InputFile, ParquetReadOptions)}
    */
+  @Deprecated
   public static ParquetMetadata readFooter(Configuration configuration, Path file, MetadataFilter filter) throws IOException {
     return readFooter(HadoopInputFile.fromPath(file, configuration), filter);
   }
@@ -518,7 +519,7 @@ private static final ParquetMetadata readFooter(InputFile file, ParquetReadOptio
     LOG.debug("File length {}", fileLen);
     int FOOTER_LENGTH_SIZE = 4;
     if (fileLen < MAGIC.length + FOOTER_LENGTH_SIZE + MAGIC.length) { // MAGIC + data + footer + footerIndex + MAGIC
-      throw new RuntimeException(file.toString() + " is not a Parquet file (too small length: " + fileLen + ")");
+      throw new RuntimeException(file + " is not a Parquet file (too small length: " + fileLen + ")");
     }
     long footerLengthIndex = fileLen - FOOTER_LENGTH_SIZE - MAGIC.length;
     LOG.debug("reading footer index at {}", footerLengthIndex);
@@ -528,7 +529,7 @@ private static final ParquetMetadata readFooter(InputFile file, ParquetReadOptio
     byte[] magic = new byte[MAGIC.length];
     f.readFully(magic);
     if (!Arrays.equals(MAGIC, magic)) {
-      throw new RuntimeException(file.toString() + " is not a Parquet file. expected magic number at tail " + Arrays.toString(MAGIC) + " but found " + Arrays.toString(magic));
+      throw new RuntimeException(file + " is not a Parquet file. expected magic number at tail " + Arrays.toString(MAGIC) + " but found " + Arrays.toString(magic));
     }
     long footerIndex = footerLengthIndex - footerLength;
     LOG.debug("read footer length: {}, footer index: {}", footerLength, footerIndex);
@@ -727,7 +728,7 @@ public ParquetFileReader(InputFile file, ParquetReadOptions options) throws IOEx
   }
 
   private static <T> List<T> listWithNulls(int size) {
-    return Stream.generate(() -> (T) null).limit(size).collect(Collectors.toCollection(ArrayList<T>::new));
+    return new ArrayList<>(Collections.nCopies(size, null));
   }
 
   public ParquetMetadata getFooter() {
@@ -750,7 +751,7 @@ public FileMetaData getFileMetaData() {
   }
 
   public long getRecordCount() {
-    long total = 0;
+    long total = 0L;
     for (BlockMetaData block : blocks) {
       total += block.getRowCount();
     }
@@ -761,7 +762,7 @@ public long getFilteredRecordCount() {
     if (!options.useColumnIndexFilter()) {
       return getRecordCount();
     }
-    long total = 0;
+    long total = 0L;
     for (int i = 0, n = blocks.size(); i < n; ++i) {
       total += getRowRanges(i).rowCount();
     }
@@ -884,7 +885,7 @@ public PageReadStore readNextFilteredRowGroup() throws IOException {
       return readNextRowGroup();
     }
     BlockMetaData block = blocks.get(currentBlock);
-    if (block.getRowCount() == 0) {
+    if (block.getRowCount() == 0L) {
       throw new RuntimeException("Illegal row group of 0 rows");
     }
     ColumnIndexStore ciStore = getColumnIndexStore(currentBlock);
@@ -903,7 +904,7 @@ public PageReadStore readNextFilteredRowGroup() throws IOException {
     this.currentRowGroup = new ColumnChunkPageReadStore(rowRanges);
     // prepare the list of consecutive parts to read them in one scan
     ChunkListBuilder builder = new ChunkListBuilder();
-    List<ConsecutivePartList> allParts = new ArrayList<ConsecutivePartList>();
+    List<ConsecutivePartList> allParts = new ArrayList<>();
     ConsecutivePartList currentParts = null;
     for (ColumnChunkMetaData mc : block.getColumns()) {
       ColumnPath pathKey = mc.getPath();
@@ -922,7 +923,7 @@ public PageReadStore readNextFilteredRowGroup() throws IOException {
             allParts.add(currentParts);
           }
           ChunkDescriptor chunkDescriptor = new ChunkDescriptor(columnDescriptor, mc, startingPos,
-              (int) range.getLength());
+              Math.toIntExact(range.getLength()));
           currentParts.addChunk(chunkDescriptor);
           builder.setOffsetIndex(chunkDescriptor, filteredOffsetIndex);
         }
@@ -1110,29 +1111,19 @@ private class ChunkData {
     private SeekableInputStream f;
 
     void add(ChunkDescriptor descriptor, List<ByteBuffer> buffers, SeekableInputStream f) {
-      ChunkData data = map.get(descriptor);
-      if (data == null) {
-        data = new ChunkData();
-        map.put(descriptor, data);
-      }
-      data.buffers.addAll(buffers);
-
+       map.computeIfAbsent(descriptor, d -> new ChunkData()).buffers.addAll(buffers);
       lastDescriptor = descriptor;
       this.f = f;
     }
 
     void setOffsetIndex(ChunkDescriptor descriptor, OffsetIndex offsetIndex) {
-      ChunkData data = map.get(descriptor);
-      if (data == null) {
-        data = new ChunkData();
-        map.put(descriptor, data);
-      }
-      data.offsetIndex = offsetIndex;
+      map.computeIfAbsent(descriptor, d -> new ChunkData()).offsetIndex = offsetIndex;
     }
 
     List<Chunk> build() {
-      List<Chunk> chunks = new ArrayList<>();
-      for (Entry<ChunkDescriptor, ChunkData> entry : map.entrySet()) {
+      Set<Entry<ChunkDescriptor, ChunkData>> entries = map.entrySet();
+      List<Chunk> chunks = new ArrayList<>(entries.size());
+      for (Entry<ChunkDescriptor, ChunkData> entry : entries) {
         ChunkDescriptor descriptor = entry.getKey();
         ChunkData data = entry.getValue();
         if (descriptor.equals(lastDescriptor)) {
@@ -1187,11 +1178,11 @@ private void verifyCrc(int referenceCrc, byte[] bytes, String exceptionMsg) {
      * @return the list of pages
      */
     public ColumnChunkPageReader readAllPages() throws IOException {
-      List<DataPage> pagesInChunk = new ArrayList<DataPage>();
+      List<DataPage> pagesInChunk = new ArrayList<>();
       DictionaryPage dictionaryPage = null;
       PrimitiveType type = getFileMetaData().getSchema()
           .getType(descriptor.col.getPath()).asPrimitiveType();
-      long valuesCountReadSoFar = 0;
+      long valuesCountReadSoFar = 0L;
       int dataPageCountReadSoFar = 0;
       while (hasMorePages(valuesCountReadSoFar, dataPageCountReadSoFar)) {
         PageHeader pageHeader = readPageHeader();
@@ -1349,11 +1340,13 @@ public BytesInput readAsBytesInput(int size) throws IOException {
         int missingBytes = size - available;
         LOG.info("completed the column chunk with {} bytes", missingBytes);
 
-        List<ByteBuffer> buffers = new ArrayList<>();
-        buffers.addAll(stream.sliceBuffers(available));
+        List<ByteBuffer> streamBuffers = stream.sliceBuffers(available);
 
         ByteBuffer lastBuffer = ByteBuffer.allocate(missingBytes);
         f.readFully(lastBuffer);
+
+        List<ByteBuffer> buffers = new ArrayList<>(streamBuffers.size() + 1);
+        buffers.addAll(streamBuffers);
         buffers.add(lastBuffer);
 
         return BytesInput.from(buffers);
@@ -1418,7 +1411,7 @@ private class ConsecutivePartList {
 
     private final long offset;
     private int length;
-    private final List<ChunkDescriptor> chunks = new ArrayList<ChunkDescriptor>();
+    private final List<ChunkDescriptor> chunks = new ArrayList<>();
 
     /**
      * @param offset where the first chunk starts
@@ -1443,7 +1436,6 @@ public void addChunk(ChunkDescriptor descriptor) {
      * @throws IOException if there is an error while reading from the stream
      */
     public void readAll(SeekableInputStream f, ChunkListBuilder builder) throws IOException {
-      List<Chunk> result = new ArrayList<Chunk>(chunks.size());
       f.seek(offset);
 
       int fullAllocations = length / options.getMaxAllocationSize();
@@ -1468,8 +1460,7 @@ public void readAll(SeekableInputStream f, ChunkListBuilder builder) throws IOEx
       // report in a counter the data we just scanned
       BenchmarkCounter.incrementBytesRead(length);
       ByteBufferInputStream stream = ByteBufferInputStream.wrap(buffers);
-      for (int i = 0; i < chunks.size(); i++) {
-        ChunkDescriptor descriptor = chunks.get(i);
+      for (final ChunkDescriptor descriptor : chunks) {
         builder.add(descriptor, stream.sliceBuffers(descriptor.size), f);
       }
     }