net.lingala.zip4j.io.inputstream.InflaterInputStream Maven / Gradle / Ivy

Go to download

Show more of this group Show more artifacts with this name
Show all versions of zip4j Show documentation

An open source java library to handle zip files

There is a newer version: 2.11.5

package net.lingala.zip4j.io.inputstream;

import java.io.EOFException;
import java.io.IOException;
import java.io.InputStream;
import java.io.PushbackInputStream;
import java.util.zip.DataFormatException;
import java.util.zip.Inflater;

public class InflaterInputStream extends DecompressedInputStream {

  private Inflater inflater;
  private byte[] buff;
  private byte[] singleByteBuffer = new byte[1];
  private int len;

  public InflaterInputStream(CipherInputStream cipherInputStream, int bufferSize) {
    super(cipherInputStream);
    this.inflater = new Inflater(true);
    buff = new byte[bufferSize];
  }

  @Override
  public int read() throws IOException {
    int readLen = read(singleByteBuffer);

    if (readLen == -1) {
      return -1;
    }

    return singleByteBuffer[0];
  }

  @Override
  public int read(byte[] b) throws IOException {
    return read(b, 0, b.length);
  }

  @Override
  public int read(byte[] b, int off, int len) throws IOException {
    try {
      int n;
      while ((n = inflater.inflate(b, off, len)) == 0) {
        if (inflater.finished() || inflater.needsDictionary()) {
          return -1;
        }
        if (inflater.needsInput()) {
          fill();
        }
      }
      return n;
    } catch (DataFormatException e) {
      throw new IOException(e);
    }
  }

  @Override
  public void endOfEntryReached(InputStream inputStream) throws IOException {
    if (inflater != null) {
      inflater.end();
      inflater = null;
    }
    super.endOfEntryReached(inputStream);
  }

  @Override
  public void pushBackInputStreamIfNecessary(PushbackInputStream pushbackInputStream) throws IOException {
    int n = inflater.getRemaining();
    if (n > 0) {
      byte[] rawDataCache = getLastReadRawDataCache();
      pushbackInputStream.unread(rawDataCache, len - n, n);
    }
  }

  @Override
  public void close() throws IOException {
    if (inflater != null) {
      inflater.end();
    }
    super.close();
  }

  private void fill() throws IOException {
    len = super.read(buff, 0, buff.length);
    if (len == -1) {
      throw new EOFException("Unexpected end of input stream");
    }
    inflater.setInput(buff, 0, len);
  }
}