content: /*
   * Copyright (c) 2006, 2013, Oracle and/or its affiliates. All rights reserved.
   * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   *
   * This code is free software; you can redistribute it and/or modify it
   * under the terms of the GNU General Public License version 2 only, as
   * published by the Free Software Foundation.  Oracle designates this
   * particular file as subject to the "Classpath" exception as provided
   * by Oracle in the LICENSE file that accompanied this code.
   *
   * This code is distributed in the hope that it will be useful, but WITHOUT
   * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
   * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
   * version 2 for more details (a copy is included in the LICENSE file that
   * accompanied this code).
   *
   * You should have received a copy of the GNU General Public License version
   * 2 along with this work; if not, write to the Free Software Foundation,
   * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
   *
   * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
   * or visit www.oracle.com if you need additional information or have any
   * questions.
   */
  
  package java.util.zip;
  
  import java.io.FilterOutputStream;
  import java.io.IOException;
  import java.io.OutputStream;
  
  /**
   * Implements an output stream filter for uncompressing data stored in the
   * "deflate" compression format.
   *
   * @since       1.6
   * @author      David R Tribble (david@tribble.com)
   *
   * @see InflaterInputStream
   * @see DeflaterInputStream
   * @see DeflaterOutputStream
   */
  
  public class InflaterOutputStream extends FilterOutputStream {
      /** Decompressor for this stream. */
      protected final Inflater inf;
  
      /** Output buffer for writing uncompressed data. */
      protected final byte[] buf;
  
      /** Temporary write buffer. */
      private final byte[] wbuf = new byte[1];
  
      /** Default decompressor is used. */
      private boolean usesDefaultInflater = false;
  
      /** true iff {@link #close()} has been called. */
      private boolean closed = false;
  
      /**
       * Checks to make sure that this stream has not been closed.
       */
      private void ensureOpen() throws IOException {
          if (closed) {
              throw new IOException("Stream closed");
          }
      }
  
      /**
       * Creates a new output stream with a default decompressor and buffer
       * size.
       *
       * @param out output stream to write the uncompressed data to
       * @throws NullPointerException if {@code out} is null
       */
      public InflaterOutputStream(OutputStream out) {
          this(out, new Inflater());
          usesDefaultInflater = true;
      }
  
      /**
       * Creates a new output stream with the specified decompressor and a
       * default buffer size.
       *
       * @param out output stream to write the uncompressed data to
       * @param infl decompressor ("inflater") for this stream
       * @throws NullPointerException if {@code out} or {@code infl} is null
       */
      public InflaterOutputStream(OutputStream out, Inflater infl) {
          this(out, infl, 512);
      }
  
      /**
       * Creates a new output stream with the specified decompressor and
       * buffer size.
       *
       * @param out output stream to write the uncompressed data to
       * @param infl decompressor ("inflater") for this stream
       * @param bufLen decompression buffer size
       * @throws IllegalArgumentException if {@code bufLen <= 0}
       * @throws NullPointerException if {@code out} or {@code infl} is null
       */
      public InflaterOutputStream(OutputStream out, Inflater infl, int bufLen) {
          super(out);
  
          // Sanity checks
          if (out == null)
              throw new NullPointerException("Null output");
          if (infl == null)
              throw new NullPointerException("Null inflater");
          if (bufLen <= 0)
              throw new IllegalArgumentException("Buffer size < 1");
  
          // Initialize
          inf = infl;
          buf = new byte[bufLen];
      }
  
      /**
       * Writes any remaining uncompressed data to the output stream and closes
       * the underlying output stream.
       *
       * @throws IOException if an I/O error occurs
       */
      public void close() throws IOException {
          if (!closed) {
              // Complete the uncompressed output
              try {
                  finish();
              } finally {
                  out.close();
                  closed = true;
              }
          }
      }
  
      /**
       * Flushes this output stream, forcing any pending buffered output bytes to be
       * written.
       *
       * @throws IOException if an I/O error occurs or this stream is already
       * closed
       */
      public void flush() throws IOException {
          ensureOpen();
  
          // Finish decompressing and writing pending output data
          if (!inf.finished()) {
              try {
                  while (!inf.finished()  &&  !inf.needsInput()) {
                      int n;
  
                      // Decompress pending output data
                      n = inf.inflate(buf, 0, buf.length);
                      if (n < 1) {
                          break;
                      }
  
                      // Write the uncompressed output data block
                      out.write(buf, 0, n);
                  }
                  super.flush();
              } catch (DataFormatException ex) {
                  // Improperly formatted compressed (ZIP) data
                  String msg = ex.getMessage();
                  if (msg == null) {
                      msg = "Invalid ZLIB data format";
                  }
                  throw new ZipException(msg);
              }
          }
      }
  
      /**
       * Finishes writing uncompressed data to the output stream without closing
       * the underlying stream.  Use this method when applying multiple filters in
       * succession to the same output stream.
       *
       * @throws IOException if an I/O error occurs or this stream is already
       * closed
       */
      public void finish() throws IOException {
          ensureOpen();
  
          // Finish decompressing and writing pending output data
          flush();
          if (usesDefaultInflater) {
              inf.end();
          }
      }
  
      /**
       * Writes a byte to the uncompressed output stream.
       *
       * @param b a single byte of compressed data to decompress and write to
       * the output stream
       * @throws IOException if an I/O error occurs or this stream is already
       * closed
       * @throws ZipException if a compression (ZIP) format error occurs
       */
      public void write(int b) throws IOException {
          // Write a single byte of data
          wbuf[0] = (byte) b;
          write(wbuf, 0, 1);
      }
  
      /**
       * Writes an array of bytes to the uncompressed output stream.
       *
       * @param b buffer containing compressed data to decompress and write to
       * the output stream
       * @param off starting offset of the compressed data within {@code b}
       * @param len number of bytes to decompress from {@code b}
       * @throws IndexOutOfBoundsException if {@code off < 0}, or if
       * {@code len < 0}, or if {@code len > b.length - off}
       * @throws IOException if an I/O error occurs or this stream is already
       * closed
       * @throws NullPointerException if {@code b} is null
       * @throws ZipException if a compression (ZIP) format error occurs
       */
      public void write(byte[] b, int off, int len) throws IOException {
          // Sanity checks
          ensureOpen();
          if (b == null) {
              throw new NullPointerException("Null buffer for read");
          } else if (off < 0 || len < 0 || len > b.length - off) {
              throw new IndexOutOfBoundsException();
          } else if (len == 0) {
              return;
          }
  
          // Write uncompressed data to the output stream
          try {
              for (;;) {
                  int n;
  
                  // Fill the decompressor buffer with output data
                  if (inf.needsInput()) {
                      int part;
  
                      if (len < 1) {
                          break;
                      }
  
                      part = (len < 512 ? len : 512);
                      inf.setInput(b, off, part);
                      off += part;
                      len -= part;
                  }
  
                  // Decompress and write blocks of output data
                  do {
                      n = inf.inflate(buf, 0, buf.length);
                      if (n > 0) {
                          out.write(buf, 0, n);
                      }
                  } while (n > 0);
  
                  // Check the decompressor
                  if (inf.finished()) {
                      break;
                  }
                  if (inf.needsDictionary()) {
                      throw new ZipException("ZLIB dictionary missing");
                  }
              }
          } catch (DataFormatException ex) {
              // Improperly formatted compressed (ZIP) data
              String msg = ex.getMessage();
              if (msg == null) {
                  msg = "Invalid ZLIB data format";
              }
              throw new ZipException(msg);
          }
      }
  }
  