Introduce S3OutputStream that uploads data to S3 directly

src/main/java/com/upplication/s3fs/S3FileSystemProvider.java

@@ -23,16 +23,19 @@
 import java.io.ByteArrayInputStream;
 import java.io.IOException;
 import java.io.InputStream;
+import java.io.OutputStream;
 import java.net.URI;
 import java.nio.channels.SeekableByteChannel;
 import java.nio.file.*;
 import java.nio.file.attribute.BasicFileAttributes;
 import java.nio.file.attribute.FileAttribute;
 import java.nio.file.attribute.FileAttributeView;
 import java.nio.file.spi.FileSystemProvider;
+import java.util.Arrays;
 import java.util.EnumSet;
 import java.util.HashMap;
 import java.util.Iterator;
+import java.util.LinkedHashSet;
 import java.util.Map;
 import java.util.Properties;
 import java.util.Set;
@@ -318,7 +321,52 @@ public InputStream newInputStream(Path path, OpenOption... options) throws IOExc
  }
 }
 
-@Override
+ @Override
+ public OutputStream newOutputStream(final Path path, final OpenOption... options) throws IOException {
+ S3Path s3Path = toS3Path(path);
+
+ // validate options
+ if (options.length > 0) {
+ Set<OpenOption> opts = new LinkedHashSet<>(Arrays.asList(options));
+
+ // cannot handle APPEND here -> use newByteChannel() implementation
+ if (opts.contains(StandardOpenOption.APPEND)) {
+ return super.newOutputStream(path, options);
+ }
+
+ if (opts.contains(StandardOpenOption.READ)) {
+ throw new IllegalArgumentException("READ not allowed");
+ }
+
+ boolean create = opts.remove(StandardOpenOption.CREATE);
+ boolean createNew = opts.remove(StandardOpenOption.CREATE_NEW);
+ boolean truncateExisting = opts.remove(StandardOpenOption.TRUNCATE_EXISTING);
+
+ // remove irrelevant/ignored options
+ opts.remove(StandardOpenOption.WRITE);
+ opts.remove(StandardOpenOption.SPARSE);
+
+ if (!opts.isEmpty()) {
+ throw new UnsupportedOperationException(opts.iterator().next() + " not supported");
+ }
+
+ if (!(create && truncateExisting)) {
+ if (s3Path.getFileSystem().provider().exists(s3Path)) {
+ if (createNew || !truncateExisting) {
+ throw new FileAlreadyExistsException(path.toString());
+ }
+ } else {
+ if (!createNew && !create) {
+ throw new NoSuchFileException(path.toString());
+ }
+ }
+ }
+ }
+
+ return new S3OutputStream(s3Path.getFileSystem().getClient(), s3Path.toS3ObjectId());
+ }
+
+ @Override
 public SeekableByteChannel newByteChannel(Path path, Set<? extends OpenOption> options, FileAttribute<?>... attrs) throws IOException {
  S3Path s3Path = toS3Path(path);
  return new S3SeekableByteChannel(s3Path, options);