Revert "[refactor] Fix issues with ByteBuffer vs Buffer API change in Java 9+"

This can be done now that `<complianceLevel>8</complianceLevel>` has been removed.

This reverts commit 3f2965f.

Author: adamretter

exist-core/src/main/java/org/exist/storage/blob/BlobStoreDumpTool.java

@@ -43,7 +43,6 @@
 
 import java.io.IOException;
 import java.io.PrintStream;
-import java.nio.Buffer;
 import java.nio.ByteBuffer;
 import java.nio.channels.SeekableByteChannel;
 import java.nio.file.Files;
@@ -128,19 +127,19 @@ public static void dump(final DigestType digestType, final Path persistentFile,
             // write a CSV table header
             printStream.println("blobId,referenceCount");
 
-            ((Buffer)buffer).clear();
+            buffer.clear();
 
             final byte[] id = new byte[digestBytesLen];
 
             while (channel.read(buffer) > -1) {
-                ((Buffer)buffer).flip();
+                buffer.flip();
                 buffer.get(id);
                 final BlobId blobId = new BlobId(id);
                 final int count = buffer.getInt();
 
                 printStream.println(blobId + "," + count);
 
-                ((Buffer)buffer).clear();
+                buffer.clear();
             }
         }
     }
@@ -157,12 +156,12 @@ public static void dump(final DigestType digestType, final Path persistentFile,
      */
     private static void dumpFileHeader(final PrintStream printStream, final ByteBuffer buffer, final Path persistentFile,
             final SeekableByteChannel channel) throws IOException {
-        ((Buffer)buffer).clear();
-        ((Buffer)buffer).limit(BLOB_STORE_HEADER_LEN);
+        buffer.clear();
+        buffer.limit(BLOB_STORE_HEADER_LEN);
 
         channel.read(buffer);
 
-        ((Buffer)buffer).flip();
+        buffer.flip();
 
         final boolean validMagic =
                 buffer.get() == BLOB_STORE_MAGIC_NUMBER[0]

exist-core/src/main/java/org/exist/storage/blob/BlobStoreImpl.java

@@ -60,7 +60,6 @@
 import java.io.IOException;
 import java.io.InputStream;
 import java.io.OutputStream;
-import java.nio.Buffer;
 import java.nio.ByteBuffer;
 import java.nio.channels.SeekableByteChannel;
 import java.nio.file.Files;
@@ -485,7 +484,7 @@ private void closeAfterRecoveryAttempt() {
      */
     private void closeBlobStore() {
         if (buffer != null) {
-            ((Buffer)buffer).clear();
+            buffer.clear();
             buffer = null;
         }
 
@@ -564,18 +563,18 @@ private ConcurrentMap<BlobId, BlobReference> compactPersistentReferences(final B
         try (final SeekableByteChannel channel = Files.newByteChannel(persistentFile, READ)) {
 
             validateFileHeader(buffer, persistentFile, channel);
-            ((Buffer)buffer).clear();
+            buffer.clear();
 
             try (final SeekableByteChannel compactChannel = Files.newByteChannel(compactPersistentFile,
                     CREATE_NEW, APPEND)) {
 
                 writeFileHeader(buffer, compactChannel);
 
-                ((Buffer)buffer).clear();
+                buffer.clear();
 
                 while (channel.read(buffer) > -1) {
                     final byte[] id = new byte[digestType.getDigestLengthBytes()];
-                    ((Buffer)buffer).flip();
+                    buffer.flip();
                     buffer.get(id);
                     final BlobId blobId = new BlobId(id);
                     final int count = buffer.getInt();
@@ -587,11 +586,11 @@ private ConcurrentMap<BlobId, BlobReference> compactPersistentReferences(final B
 
                         compactReferences.put(blobId, new BlobReference(count, compactChannel.position()));
 
-                        ((Buffer)buffer).flip();
+                        buffer.flip();
                         compactChannel.write(buffer);
                     }
 
-                    ((Buffer)buffer).clear();
+                    buffer.clear();
                 }
             }
         }
@@ -618,11 +617,11 @@ private ConcurrentMap<BlobId, BlobReference> compactPersistentReferences(final B
     private long writeFileHeader(final ByteBuffer buffer, final SeekableByteChannel channel) throws IOException {
         final long start = channel.position();
 
-        ((Buffer)buffer).clear();
+        buffer.clear();
         writeFileHeader(buffer);
 
-        ((Buffer)buffer).flip();
-        ((Buffer)buffer).limit(BLOB_STORE_HEADER_LEN);
+        buffer.flip();
+        buffer.limit(BLOB_STORE_HEADER_LEN);
         channel.write(buffer);
 
         return channel.position() - start;
@@ -649,12 +648,12 @@ private static void writeFileHeader(final ByteBuffer buffer) {
      */
     private void validateFileHeader(final ByteBuffer buffer, final Path file, final SeekableByteChannel channel)
             throws IOException {
-        ((Buffer)buffer).clear();
-        ((Buffer)buffer).limit(BLOB_STORE_HEADER_LEN);
+        buffer.clear();
+        buffer.limit(BLOB_STORE_HEADER_LEN);
 
         channel.read(buffer);
 
-        ((Buffer)buffer).flip();
+        buffer.flip();
 
         final boolean validMagic =
                 buffer.get() == BLOB_STORE_MAGIC_NUMBER[0]
@@ -1217,26 +1216,26 @@ private void undoStoreBlobFile(final BlobId blobId, final String stagedUuid) thr
      * @throws IOException if the blob's reference count cannot be set
      */
     private void updateBlogRefCount(final BlobId blobId, final int count) throws IOException {
-        ((Buffer)buffer).clear();
-        ((Buffer)buffer).limit(digestType.getDigestLengthBytes());  // we are only going to read the BlobIds
+        buffer.clear();
+        buffer.limit(digestType.getDigestLengthBytes());  // we are only going to read the BlobIds
 
         // start immediately after the file header
         channel.position(BLOB_STORE_HEADER_LEN);
 
         boolean updatedCount = false;
 
         while (channel.read(buffer) > 0) {
-            ((Buffer)buffer).flip();
+            buffer.flip();
             final byte[] id = new byte[digestType.getDigestLengthBytes()];
             buffer.get(id);
             final BlobId readBlobId = new BlobId(id);
 
             if (blobId.equals(readBlobId)) {
 
-                ((Buffer)buffer).clear();
-                ((Buffer)buffer).limit(REFERENCE_COUNT_LEN);
+                buffer.clear();
+                buffer.limit(REFERENCE_COUNT_LEN);
                 buffer.putInt(count);
-                ((Buffer)buffer).flip();
+                buffer.flip();
 
                 channel.write(buffer);
 
@@ -1255,11 +1254,11 @@ private void updateBlogRefCount(final BlobId blobId, final int count) throws IOE
          * the next call to compactPersistentReferences
          */
         if (!updatedCount) {
-            ((Buffer)buffer).clear();
+            buffer.clear();
             buffer.put(blobId.getId());
             buffer.putInt(count);
 
-            ((Buffer)buffer).flip();
+            buffer.flip();
 
             channel.write(buffer);
         }
@@ -1618,10 +1617,10 @@ private void writeEntry(final BlobId blobId, final BlobReference blobReference,
 
             channel.position(blobReference.persistentOffset);
 
-            ((Buffer)buffer).clear();
+            buffer.clear();
             buffer.put(blobId.getId());
             buffer.putInt(newCount);
-            ((Buffer)buffer).flip();
+            buffer.flip();
 
             channel.write(buffer);
         }

exist-core/src/main/java/org/exist/storage/journal/Journal.java

@@ -22,7 +22,6 @@
 package org.exist.storage.journal;
 
 import java.io.*;
-import java.nio.Buffer;
 import java.nio.BufferOverflowException;
 import java.nio.ByteBuffer;
 import java.nio.channels.FileChannel;
@@ -353,14 +352,14 @@ public synchronized void writeToLog(final Loggable entry) throws JournalExceptio
             // TODO(AR) this is needed as the journal is initialised by starting a transaction for loading the SymbolTable... before recovery! which is likely wrong!!! as Recovery Cannot run if the Journal file has been switched!
             final long pos = channel != null ? channel.position() : 0;
 
-            currentLsn = new Lsn(currentJournalFileNumber, pos + ((Buffer)currentBuffer).position() + 1);
+            currentLsn = new Lsn(currentJournalFileNumber, pos + currentBuffer.position() + 1);
         } catch (final IOException e) {
             throw new JournalException("Unable to create LSN for: " + entry.dump());
         }
         entry.setLsn(currentLsn);
 
         try {
-            final int currentBufferEntryOffset = ((Buffer)currentBuffer).position();
+            final int currentBufferEntryOffset = currentBuffer.position();
 
             // write entryHeader
             currentBuffer.put(entry.getLogType());
@@ -374,7 +373,7 @@ public synchronized void writeToLog(final Loggable entry) throws JournalExceptio
             currentBuffer.putShort((short) (size + LOG_ENTRY_HEADER_LEN));
 
             // write checksum
-            final long checksum = xxHash64.hash(currentBuffer, currentBufferEntryOffset, ((Buffer)currentBuffer).position() - currentBufferEntryOffset, XXHASH64_SEED);
+            final long checksum = xxHash64.hash(currentBuffer, currentBufferEntryOffset, currentBuffer.position() - currentBufferEntryOffset, XXHASH64_SEED);
             currentBuffer.putLong(checksum);
         } catch (final BufferOverflowException e) {
             throw new JournalException("Buffer overflow while writing log record: " + entry.dump(), e);
@@ -450,8 +449,8 @@ private void flushBuffer() {
         }
 
         try {
-            if (((Buffer)currentBuffer).position() > 0) {
-                ((Buffer)currentBuffer).flip();
+            if (currentBuffer.position() > 0) {
+                currentBuffer.flip();
                 final int size = currentBuffer.remaining();
                 while (currentBuffer.hasRemaining()) {
                     channel.write(currentBuffer);
@@ -462,7 +461,7 @@ private void flushBuffer() {
         } catch (final IOException e) {
             LOG.warn("Flushing log file failed!", e);
         } finally {
-            ((Buffer)currentBuffer).clear();
+            currentBuffer.clear();
         }
     }
 
@@ -600,7 +599,7 @@ static void writeJournalHeader(final SeekableByteChannel channel) throws IOExcep
         ByteConversion.shortToByteH(JOURNAL_VERSION, journalVersion, 0);
         buf.put(journalVersion);
 
-        ((Buffer)buf).flip();
+        buf.flip();
         channel.write(buf);
     }
 

exist-core/src/main/java/org/exist/storage/journal/JournalReader.java

@@ -30,7 +30,6 @@
 
 import javax.annotation.Nullable;
 import java.io.IOException;
-import java.nio.Buffer;
 import java.nio.ByteBuffer;
 import java.nio.channels.SeekableByteChannel;
 import java.nio.file.Files;
@@ -83,7 +82,7 @@ private void validateJournalHeader(final Path file, final SeekableByteChannel fc
         // read the magic number
         final ByteBuffer buf = ByteBuffer.allocateDirect(JOURNAL_HEADER_LEN);
         fc.read(buf);
-        ((Buffer)buf).flip();
+        buf.flip();
 
         // check the magic number
         final boolean validMagic =
@@ -146,12 +145,12 @@ Loggable previousEntry() throws LogException {
 
             // go back 8 bytes (checksum length) + 2 bytes (backLink length) and read the backLink (2 bytes) of the last entry
             fc.position(fc.position() - LOG_ENTRY_CHECKSUM_LEN - LOG_ENTRY_BACK_LINK_LEN);
-            ((Buffer)header).clear().limit(LOG_ENTRY_BACK_LINK_LEN);
+            header.clear().limit(LOG_ENTRY_BACK_LINK_LEN);
             final int read = fc.read(header);
             if (read != LOG_ENTRY_BACK_LINK_LEN) {
                 throw new LogException("Unable to read journal entry back-link!");
             }
-            ((Buffer)header).flip();
+            header.flip();
             final short backLink = header.getShort();
 
             // position the channel to the start of the previous entry and mark it
@@ -196,7 +195,7 @@ Loggable readEntry() throws LogException {
             final Lsn lsn = new Lsn(fileNumber, fc.position() + 1);
 
             // read the entry header
-            ((Buffer)header).clear();
+            header.clear();
             int read = fc.read(header);
             if (read <= 0) {
                 return null;
@@ -205,19 +204,19 @@ Loggable readEntry() throws LogException {
                 throw new LogException("Incomplete journal entry header found, expected  "
                         + LOG_ENTRY_HEADER_LEN + " bytes, but found " + read + " bytes");
             }
-            ((Buffer)header).flip();
+            header.flip();
 
             // prepare the checksum for the header
             xxHash64.reset();
             if (header.hasArray()) {
                 xxHash64.update(header.array(), 0, LOG_ENTRY_HEADER_LEN);
             } else {
-                final int mark = ((Buffer)header).position();
-                ((Buffer)header).position(0);
+                final int mark = header.position();
+                header.position(0);
                 final byte buf[] = new byte[LOG_ENTRY_HEADER_LEN];
                 header.get(buf);
                 xxHash64.update(buf, 0, LOG_ENTRY_HEADER_LEN);
-                ((Buffer)header).position(mark);
+                header.position(mark);
             }
 
             final byte entryType = header.get();
@@ -240,12 +239,12 @@ Loggable readEntry() throws LogException {
                 // resize the payload buffer
                 payload = ByteBuffer.allocateDirect(remainingEntryBytes);
             }
-            ((Buffer)payload).clear().limit(remainingEntryBytes);
+            payload.clear().limit(remainingEntryBytes);
             read = fc.read(payload);
             if (read < remainingEntryBytes) {
                 throw new LogException("Incomplete log entry found!");
             }
-            ((Buffer)payload).flip();
+            payload.flip();
 
             // read entry data
             loggable.read(payload);
@@ -261,12 +260,12 @@ Loggable readEntry() throws LogException {
             if (payload.hasArray()) {
                 xxHash64.update(payload.array(), 0, size + LOG_ENTRY_BACK_LINK_LEN);
             } else {
-                final int mark = ((Buffer)payload).position();
-                ((Buffer)payload).position(0);
+                final int mark = payload.position();
+                payload.position(0);
                 final byte buf[] = new byte[size + LOG_ENTRY_BACK_LINK_LEN];
                 payload.get(buf);
                 xxHash64.update(buf, 0, size + LOG_ENTRY_BACK_LINK_LEN);
-                ((Buffer)payload).position(mark);
+                payload.position(mark);
             }
 
             // read the entry checksum

exist-core/src/main/java/org/exist/storage/lock/FileLock.java

@@ -28,7 +28,6 @@
 import org.exist.util.ReadOnlyException;
 
 import java.io.IOException;
-import java.nio.Buffer;
 import java.nio.ByteBuffer;
 import java.nio.channels.SeekableByteChannel;
 import java.nio.file.Files;
@@ -238,10 +237,10 @@ protected void save() throws IOException {
             }
 
             long now = System.currentTimeMillis();
-            ((Buffer)buf).clear();
+            buf.clear();
             buf.put(MAGIC);
             buf.putLong(now);
-            ((Buffer)buf).flip();
+            buf.flip();
             channel.position(0);
             channel.write(buf);
             //channel.force(true); //handled by SYNC on open option
@@ -262,9 +261,9 @@ private void read() throws IOException {
         }
 
         channel.read(buf);
-        ((Buffer)buf).flip();
-        if (((Buffer)buf).limit() < 16) {
-            ((Buffer)buf).clear();
+        buf.flip();
+        if (buf.limit() < 16) {
+            buf.clear();
             throw new IOException(message("Could not read file lock.", null));
         }
 
@@ -275,7 +274,7 @@ private void read() throws IOException {
         }
 
         lastHeartbeat = buf.getLong();
-        ((Buffer)buf).clear();
+        buf.clear();
 
         final DateFormat df = DateFormat.getDateInstance();
         message("File lock last access timestamp: " + df.format(getLastHeartbeat()), null);