UrlsController/src/main/java/eu/openaire/urls_controller/util/FileDecompressor.java

57 lines
2.3 KiB
Java

package eu.openaire.urls_controller.util;
import org.apache.commons.compress.archivers.tar.TarArchiveEntry;
import org.apache.commons.compress.archivers.tar.TarArchiveInputStream;
import org.apache.commons.compress.compressors.zstandard.ZstdCompressorInputStream;
import org.apache.commons.lang.StringUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.stereotype.Component;
import java.io.BufferedInputStream;
import java.io.OutputStream;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.Paths;
import java.nio.file.StandardCopyOption;
@Component
public class FileDecompressor {
private static final Logger logger = LoggerFactory.getLogger(FileDecompressor.class);
public void decompressFiles(String zstdSource, Path targetDir) throws Exception
{
// Decompress the zstd file.
Path tarPath = Paths.get(StringUtils.replace(zstdSource, ".zstd", "", 1)); // Remove the ".zstd" extension.
try ( ZstdCompressorInputStream zsIn = new ZstdCompressorInputStream(new BufferedInputStream(Files.newInputStream(Paths.get(zstdSource))));
OutputStream out = Files.newOutputStream(tarPath) )
{
final byte[] buffer = new byte[1048576]; // 1 Mb
int n = 0;
while ( (n = zsIn.read(buffer)) != -1 ) {
out.write(buffer, 0, n);
}
}
// Now we have a decompressed tar-file, which we will Un-tar, in order to extract the full-text files.
try ( TarArchiveInputStream tarInput = new TarArchiveInputStream(new BufferedInputStream(Files.newInputStream(tarPath))) )
{
TarArchiveEntry entry;
while ( ((entry = (TarArchiveEntry) tarInput.getNextEntry()) != null) )
{
String entryName = entry.getName();
Path targetFilePath = targetDir.resolve(entryName);
Files.copy(tarInput, targetFilePath, StandardCopyOption.REPLACE_EXISTING); // Copy an individual entry.
// No need to close the tarEntry.
}
}
// Now we have a batch-directory which contains the tar-file along with the extracted full-text files.
// After uploading the full-texts, the batch-directories will be deleted.
}
}