org.apache.commons.compress.archivers.zip

## Class ZipArchiveInputStream

- java.lang.Object
- - java.io.InputStream
  - - org.apache.commons.compress.archivers.ArchiveInputStream
    - - org.apache.commons.compress.archivers.zip.ZipArchiveInputStream

- All Implemented Interfaces:
    Closeable, AutoCloseable
  Direct Known Subclasses:
    JarArchiveInputStream

      public class ZipArchiveInputStream
      extends ArchiveInputStream

  Implements an input stream that can read Zip archives.

  As of Apache Commons Compress it transparently supports Zip64 extensions and thus individual entries and archives larger than 4 GB or with more than 65536 entries.

  The `ZipFile` class is preferred when reading from files as `ZipArchiveInputStream` is limited by not being able to read the central directory header before returning entries. In particular `ZipArchiveInputStream`

  - may return entries that are not part of the central directory at all and shouldn't be considered part of the archive.
  - may return several entries with the same name.
  - will not return internal or external attributes.
  - may return incomplete extra field data.
  - may return unknown sizes and CRC values for entries until the next entry has been reached if the archive uses the data descriptor feature.
  See Also:
    `ZipFile`
  This class is not thread-safe

- - ### Constructor Summary

    Constructors
    Constructor and Description
    `ZipArchiveInputStream(InputStream inputStream)` Create an instance using UTF-8 encoding
    `ZipArchiveInputStream(InputStream inputStream, String encoding)` Create an instance using the specified encoding
    `ZipArchiveInputStream(InputStream inputStream, String encoding, boolean useUnicodeExtraFields)` Create an instance using the specified encoding
    `ZipArchiveInputStream(InputStream inputStream, String encoding, boolean useUnicodeExtraFields, boolean allowStoredEntriesWithDataDescriptor)` Create an instance using the specified encoding

  - ### Method Summary

    Methods
    Modifier and Type | Method and Description
    --- | ---
    `boolean` | `canReadEntryData(ArchiveEntry ae)` Whether this class is able to read the given entry.
    `void` | `close()`
    `ArchiveEntry` | `getNextEntry()` Returns the next Archive Entry in this Stream.
    `ZipArchiveEntry` | `getNextZipEntry()`
    `static boolean` | `matches(byte[] signature, int length)` Checks if the signature matches what is expected for a zip file.
    `int` | `read(byte[] buffer, int offset, int length)`
    `long` | `skip(long value)` Skips over and discards value bytes of data from this input stream.

    - ### Methods inherited from class org.apache.commons.compress.archivers.ArchiveInputStream

      `count, count, getBytesRead, getCount, pushedBackBytes, read`

    - ### Methods inherited from class java.io.InputStream

      `available, mark, markSupported, read, reset`

    - ### Methods inherited from class java.lang.Object

      `clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait`

- - ### Constructor Detail

    - #### ZipArchiveInputStream

          public ZipArchiveInputStream(InputStream inputStream)

      Create an instance using UTF-8 encoding
      Parameters:
        `inputStream` - the stream to wrap

    - #### ZipArchiveInputStream

          public ZipArchiveInputStream(InputStream inputStream,
                               String encoding)

      Create an instance using the specified encoding
      Parameters:
        `inputStream` - the stream to wrap
        `encoding` - the encoding to use for file names, use null for the platform's default encoding
      Since:
        1.5

    - #### ZipArchiveInputStream

          public ZipArchiveInputStream(InputStream inputStream,
                               String encoding,
                               boolean useUnicodeExtraFields)

      Create an instance using the specified encoding
      Parameters:
        `inputStream` - the stream to wrap
        `encoding` - the encoding to use for file names, use null for the platform's default encoding
        `useUnicodeExtraFields` - whether to use InfoZIP Unicode Extra Fields (if present) to set the file names.

    - #### ZipArchiveInputStream

          public ZipArchiveInputStream(InputStream inputStream,
                               String encoding,
                               boolean useUnicodeExtraFields,
                               boolean allowStoredEntriesWithDataDescriptor)

      Create an instance using the specified encoding
      Parameters:
        `inputStream` - the stream to wrap
        `encoding` - the encoding to use for file names, use null for the platform's default encoding
        `useUnicodeExtraFields` - whether to use InfoZIP Unicode Extra Fields (if present) to set the file names.
        `allowStoredEntriesWithDataDescriptor` - whether the stream will try to read STORED entries that use a data descriptor
      Since:
        1.1

  - ### Method Detail

    - #### getNextZipEntry

          public ZipArchiveEntry getNextZipEntry()
                                          throws IOException

      Throws:
        `IOException`

    - #### getNextEntry

          public ArchiveEntry getNextEntry()
                                    throws IOException

      Description copied from class: `ArchiveInputStream`
      Returns the next Archive Entry in this Stream.
      Specified by:
        `getNextEntry` in class `ArchiveInputStream`
      Returns:
        the next entry, or `null` if there are no more entries
      Throws:
        `IOException` - if the next entry could not be read

    - #### canReadEntryData

          public boolean canReadEntryData(ArchiveEntry ae)

      Whether this class is able to read the given entry.

      May return false if it is set up to use encryption or a compression method that hasn't been implemented yet.

      Overrides:
        `canReadEntryData` in class `ArchiveInputStream`
      Parameters:
        `ae` - the entry to test
      Returns:
        This implementation always returns true.
      Since:
        1.1

    - #### read

          public int read(byte[] buffer,
                 int offset,
                 int length)
                   throws IOException

      Overrides:
        `read` in class `InputStream`
      Throws:
        `IOException`

    - #### close

          public void close()
                     throws IOException

      Specified by:
        `close` in interface `Closeable`
      Specified by:
        `close` in interface `AutoCloseable`
      Overrides:
        `close` in class `InputStream`
      Throws:
        `IOException`

    - #### skip

          public long skip(long value)
                    throws IOException

      Skips over and discards value bytes of data from this input stream.

      This implementation may end up skipping over some smaller number of bytes, possibly 0, if and only if it reaches the end of the underlying stream.

      The actual number of bytes skipped is returned.

      Overrides:
        `skip` in class `InputStream`
      Parameters:
        `value` - the number of bytes to be skipped.
      Returns:
        the actual number of bytes skipped.
      Throws:
        `IOException` - - if an I/O error occurs.
        `IllegalArgumentException` - - if value is negative.

    - #### matches

          public static boolean matches(byte[] signature,
                        int length)

      Checks if the signature matches what is expected for a zip file. Does not currently handle self-extracting zips which may have arbitrary leading content.
      Parameters:
        `signature` - the bytes to check
        `length` - the number of bytes to check
      Returns:
        true, if this stream is a zip archive stream, false otherwise

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