Junrar

Read and extracts from a .rar file. This is a fork of the junrar codebase, formerly on sourceforge.

Code may not be used to develop a RAR (WinRAR) compatible archiver.

• RAR up to v7
• password protected archives (also with encrypted headers)
• multi-part archives
• extract from File and InputStream
• extract to File and OutputStream

implementation "com.github.junrar:junrar:{version}"

implementation("com.github.junrar:junrar:{version}")

<dependency>
  <groupId>com.github.junrar</groupId>
  <artifactId>junrar</artifactId>
  <version>{version}</version>
</dependency>

where {version} corresponds to version as below:

• Java 8 Version:
• Java 6 Compatible Version:

Apache Commons VFS support has been removed from 5.0.0, and moved to a dedicated repo: https://github.com/junrar/commons-vfs-rar

Junrar.extract("/tmp/foo.rar", "/tmp");
//or
final File rar = new File("foo.rar");  
final File destinationFolder = new File("destinationFolder");
Junrar.extract(rar, destinationFolder);    
//or
final InputStream resourceAsStream = Foo.class.getResourceAsStream("foo.rar");//only for a single rar file
Junrar.extract(resourceAsStream, tempFolder);

// Assuming you already have an InputStream from the rar file and an OutputStream for writing to
final Archive archive = new Archive(inputStream);
while (true) {
  FileHeader fileHeader = archive.nextFileHeader();
  if (fileHeader == null) {
      break;
  }
  archive.extractFile(fileHeader, outputStream); 
}

// Assuming you already have an InputStream from the rar file and an OutputStream for writing to
final Archive archive = new Archive(inputStream);
while (true) {
  FileHeader fileHeader = archive.nextFileHeader();
  if (fileHeader == null) {
      break;
  }
  try (InputStream is = archive.getInputStream(fileHeader)) {
      // Then use the InputStream for any method that uses that as an input, ex.:
      Files.copy(is, Paths.get("destinationFile.txt"));
  }
}

If extraction fails (for example on a CRC mismatch), a read throws an IOException whose cause is the original exception, at the latest the read that reaches the entry's declared size. An entry whose stream you read up to its full size without an exception has been verified; closing the stream earlier abandons the entry.

Archive is not thread-safe. Use each instance from one thread at a time, and read the streams it returns one at a time. The static Junrar methods open their own Archive on each call.

final List<ContentDescription> contentDescriptions = Junrar.getContentsDescription(testDocuments);    

Junrar.extract("/tmp/foo.rar", "/tmp", "password");
//or
final File rar = new File("foo.rar");  
final File destinationFolder = new File("destinationFolder");
Junrar.extract(rar, destinationFolder, "password");    
//or
final InputStream resourceAsStream = Foo.class.getResourceAsStream("foo.rar");//only for a single rar file
Junrar.extract(resourceAsStream, tempFolder, "password");

Junrar.extract("/tmp/foo.001.rar", "/tmp");

Junrar allows for some tuning using System Properties:

• Options for Archive#getInputStream(FileHeader):
  • junrar.extractor.buffer-size: accepts any positive integer. Defaults to 32 * 1024.
    • Sets the maximum size used for the dynamic byte buffer in the PipedInputStream.
  • junrar.extractor.use-executor: accepts either true or false. Defaults to true.
    • If true, it uses a cached thread pool for extracting the contents, which is generally faster.
    • If false, it will create a new thread on each call. This may be slower, but may require slightly less memory.
    • Options for tuning the thread pool:
      • junrar.extractor.max-threads: accepts any positive integer. Defaults to 2^31.
        • Sets the maximum number of threads to be used in the pool. By default, there is no hard limit on the number of threads, but they are only created when needed, so the maximum should not exceed the number of threads calling this method at any given moment. Use this if you need to restrict the number of threads.
      • junrar.extractor.thread-keep-alive-seconds: accepts any positive integer. Defaults to 5.
        • Sets the number of seconds a thread can be kept alive in the pool, waiting for a next extraction operation. After that time, the thread may be stopped.