Package org.apache.commons.compress.archivers.sevenz

Class SevenZFile

  • All Implemented Interfaces:
    java.io.Closeable, java.lang.AutoCloseable
    public class SevenZFile
extends java.lang.Object
implements java.io.Closeable
    Reads a 7z file, using SeekableByteChannel under the covers.

    The 7z file format is a flexible container that can contain many compression and encryption types, but at the moment only only Copy, LZMA, LZMA2, BZIP2, Deflate and AES-256 + SHA-256 are supported.

    The format is very Windows/Intel specific, so it uses little-endian byte order, doesn't store user/group or permission bits, and represents times using NTFS timestamps (100 nanosecond units since 1 January 1601). Hence the official tools recommend against using it for backup purposes on *nix, and recommend .tar.7z or .tar.lzma or .tar.xz instead.

    Both the header and file contents may be compressed and/or encrypted. With both encrypted, neither file names nor file contents can be read, but the use of encryption isn't plausibly deniable.

    Multi volume archives can be read by concatenating the parts in correct order - either manually or by using {link org.apache.commons.compress.utils.MultiReadOnlySeekableByteChannel} for example.

    Since:
    1.6

    • Constructor Summary

      Constructors 
      Constructor Description
      SevenZFile​(java.io.File fileName)
      Reads a file as unencrypted 7z archive
      SevenZFile​(java.io.File fileName, byte[] password)
      Deprecated.
      use the char[]-arg version for the password instead
      SevenZFile​(java.io.File fileName, char[] password)
      Reads a file as 7z archive
      SevenZFile​(java.io.File fileName, char[] password, SevenZFileOptions options)
      Reads a file as 7z archive with additional options.
      SevenZFile​(java.io.File fileName, SevenZFileOptions options)
      Reads a file as unencrypted 7z archive
      SevenZFile​(java.nio.channels.SeekableByteChannel channel)
      Reads a SeekableByteChannel as 7z archive
      SevenZFile​(java.nio.channels.SeekableByteChannel channel, byte[] password)
      Deprecated.
      use the char[]-arg version for the password instead
      SevenZFile​(java.nio.channels.SeekableByteChannel channel, char[] password)
      Reads a SeekableByteChannel as 7z archive
      SevenZFile​(java.nio.channels.SeekableByteChannel channel, char[] password, SevenZFileOptions options)
      Reads a SeekableByteChannel as 7z archive with additional options.
      SevenZFile​(java.nio.channels.SeekableByteChannel channel, java.lang.String fileName)
      Reads a SeekableByteChannel as 7z archive
      SevenZFile​(java.nio.channels.SeekableByteChannel channel, java.lang.String fileName, byte[] password)
      Deprecated.
      use the char[]-arg version for the password instead
      SevenZFile​(java.nio.channels.SeekableByteChannel channel, java.lang.String fileName, char[] password)
      Reads a SeekableByteChannel as 7z archive
      SevenZFile​(java.nio.channels.SeekableByteChannel channel, java.lang.String fileName, char[] password, SevenZFileOptions options)
      Reads a SeekableByteChannel as 7z archive with addtional options.
      SevenZFile​(java.nio.channels.SeekableByteChannel channel, java.lang.String fileName, SevenZFileOptions options)
      Reads a SeekableByteChannel as 7z archive with additional options.
      SevenZFile​(java.nio.channels.SeekableByteChannel channel, SevenZFileOptions options)
      Reads a SeekableByteChannel as 7z archive with addtional options.

    • Constructor Detail

      • SevenZFile

        public SevenZFile​(java.io.File fileName,
                  char[] password)
           throws java.io.IOException
        Reads a file as 7z archive
        Parameters:
        fileName - the file to read
        password - optional password if the archive is encrypted
        Throws:
        java.io.IOException - if reading the archive fails
        Since:
        1.17

      • SevenZFile

        public SevenZFile​(java.io.File fileName,
                  char[] password,
                  SevenZFileOptions options)
           throws java.io.IOException
        Reads a file as 7z archive with additional options.
        Parameters:
        fileName - the file to read
        password - optional password if the archive is encrypted
        options - the options to apply
        Throws:
        java.io.IOException - if reading the archive fails or the memory limit (if set) is too small
        Since:
        1.19

      • SevenZFile

        @Deprecated
public SevenZFile​(java.io.File fileName,
                  byte[] password)
           throws java.io.IOException
        Deprecated.
        use the char[]-arg version for the password instead
        Reads a file as 7z archive
        Parameters:
        fileName - the file to read
        password - optional password if the archive is encrypted - the byte array is supposed to be the UTF16-LE encoded representation of the password.
        Throws:
        java.io.IOException - if reading the archive fails

      • SevenZFile

        public SevenZFile​(java.nio.channels.SeekableByteChannel channel)
           throws java.io.IOException
        Reads a SeekableByteChannel as 7z archive

        SeekableInMemoryByteChannel allows you to read from an in-memory archive.

        Parameters:
        channel - the channel to read
        Throws:
        java.io.IOException - if reading the archive fails
        Since:
        1.13

      • SevenZFile

        public SevenZFile​(java.nio.channels.SeekableByteChannel channel,
                  SevenZFileOptions options)
           throws java.io.IOException
        Reads a SeekableByteChannel as 7z archive with addtional options.

        SeekableInMemoryByteChannel allows you to read from an in-memory archive.

        Parameters:
        channel - the channel to read
        options - the options to apply
        Throws:
        java.io.IOException - if reading the archive fails or the memory limit (if set) is too small
        Since:
        1.19

      • SevenZFile

        public SevenZFile​(java.nio.channels.SeekableByteChannel channel,
                  char[] password)
           throws java.io.IOException
        Reads a SeekableByteChannel as 7z archive

        SeekableInMemoryByteChannel allows you to read from an in-memory archive.

        Parameters:
        channel - the channel to read
        password - optional password if the archive is encrypted
        Throws:
        java.io.IOException - if reading the archive fails
        Since:
        1.17

      • SevenZFile

        public SevenZFile​(java.nio.channels.SeekableByteChannel channel,
                  char[] password,
                  SevenZFileOptions options)
           throws java.io.IOException
        Reads a SeekableByteChannel as 7z archive with additional options.

        SeekableInMemoryByteChannel allows you to read from an in-memory archive.

        Parameters:
        channel - the channel to read
        password - optional password if the archive is encrypted
        options - the options to apply
        Throws:
        java.io.IOException - if reading the archive fails or the memory limit (if set) is too small
        Since:
        1.19

      • SevenZFile

        public SevenZFile​(java.nio.channels.SeekableByteChannel channel,
                  java.lang.String fileName,
                  char[] password)
           throws java.io.IOException
        Reads a SeekableByteChannel as 7z archive

        SeekableInMemoryByteChannel allows you to read from an in-memory archive.

        Parameters:
        channel - the channel to read
        fileName - name of the archive - only used for error reporting
        password - optional password if the archive is encrypted
        Throws:
        java.io.IOException - if reading the archive fails
        Since:
        1.17

      • SevenZFile

        public SevenZFile​(java.nio.channels.SeekableByteChannel channel,
                  java.lang.String fileName,
                  char[] password,
                  SevenZFileOptions options)
           throws java.io.IOException
        Reads a SeekableByteChannel as 7z archive with addtional options.

        SeekableInMemoryByteChannel allows you to read from an in-memory archive.

        Parameters:
        channel - the channel to read
        fileName - name of the archive - only used for error reporting
        password - optional password if the archive is encrypted
        options - the options to apply
        Throws:
        java.io.IOException - if reading the archive fails or the memory limit (if set) is too small
        Since:
        1.19

      • SevenZFile

        public SevenZFile​(java.nio.channels.SeekableByteChannel channel,
                  java.lang.String fileName)
           throws java.io.IOException
        Reads a SeekableByteChannel as 7z archive

        SeekableInMemoryByteChannel allows you to read from an in-memory archive.

        Parameters:
        channel - the channel to read
        fileName - name of the archive - only used for error reporting
        Throws:
        java.io.IOException - if reading the archive fails
        Since:
        1.17

      • SevenZFile

        public SevenZFile​(java.nio.channels.SeekableByteChannel channel,
                  java.lang.String fileName,
                  SevenZFileOptions options)
           throws java.io.IOException
        Reads a SeekableByteChannel as 7z archive with additional options.

        SeekableInMemoryByteChannel allows you to read from an in-memory archive.

        Parameters:
        channel - the channel to read
        fileName - name of the archive - only used for error reporting
        options - the options to apply
        Throws:
        java.io.IOException - if reading the archive fails or the memory limit (if set) is too small
        Since:
        1.19

      • SevenZFile

        @Deprecated
public SevenZFile​(java.nio.channels.SeekableByteChannel channel,
                  byte[] password)
           throws java.io.IOException
        Deprecated.
        use the char[]-arg version for the password instead
        Reads a SeekableByteChannel as 7z archive

        SeekableInMemoryByteChannel allows you to read from an in-memory archive.

        Parameters:
        channel - the channel to read
        password - optional password if the archive is encrypted - the byte array is supposed to be the UTF16-LE encoded representation of the password.
        Throws:
        java.io.IOException - if reading the archive fails
        Since:
        1.13

      • SevenZFile

        @Deprecated
public SevenZFile​(java.nio.channels.SeekableByteChannel channel,
                  java.lang.String fileName,
                  byte[] password)
           throws java.io.IOException
        Deprecated.
        use the char[]-arg version for the password instead
        Reads a SeekableByteChannel as 7z archive

        SeekableInMemoryByteChannel allows you to read from an in-memory archive.

        Parameters:
        channel - the channel to read
        fileName - name of the archive - only used for error reporting
        password - optional password if the archive is encrypted - the byte array is supposed to be the UTF16-LE encoded representation of the password.
        Throws:
        java.io.IOException - if reading the archive fails
        Since:
        1.13

      • SevenZFile

        public SevenZFile​(java.io.File fileName)
           throws java.io.IOException
        Reads a file as unencrypted 7z archive
        Parameters:
        fileName - the file to read
        Throws:
        java.io.IOException - if reading the archive fails

      • SevenZFile

        public SevenZFile​(java.io.File fileName,
                  SevenZFileOptions options)
           throws java.io.IOException
        Reads a file as unencrypted 7z archive
        Parameters:
        fileName - the file to read
        options - the options to apply
        Throws:
        java.io.IOException - if reading the archive fails or the memory limit (if set) is too small
        Since:
        1.19

    • Method Detail

      • close

        public void close()
           throws java.io.IOException
        Closes the archive.
        Specified by:
        close in interface java.lang.AutoCloseable
        Specified by:
        close in interface java.io.Closeable
        Throws:
        java.io.IOException - if closing the file fails

      • getNextEntry

        public SevenZArchiveEntry getNextEntry()
                                throws java.io.IOException
        Returns the next Archive Entry in this archive.
        Returns:
        the next entry, or null if there are no more entries
        Throws:
        java.io.IOException - if the next entry could not be read

      • getEntries

        public java.lang.Iterable<SevenZArchiveEntry> getEntries()
        Returns a copy of meta-data of all archive entries.

        This method only provides meta-data, the entries can not be used to read the contents, you still need to process all entries in order using getNextEntry() for that.

        The content methods are only available for entries that have already been reached via getNextEntry().

        Returns:
        a copy of meta-data of all archive entries.
        Since:
        1.11

      • read

        public int read()
         throws java.io.IOException
        Reads a byte of data.
        Returns:
        the byte read, or -1 if end of input is reached
        Throws:
        java.io.IOException - if an I/O error has occurred

      • getInputStream

        public java.io.InputStream getInputStream​(SevenZArchiveEntry entry)
                                   throws java.io.IOException
        Returns an InputStream for reading the contents of the given entry.

        For archives using solid compression randomly accessing entries will be significantly slower than reading the archive sequentially.

        Parameters:
        entry - the entry to get the stream for.
        Returns:
        a stream to read the entry from.
        Throws:
        java.io.IOException - if unable to create an input stream from the zipentry
        Since:
        Compress 1.20

      • read

        public int read​(byte[] b)
         throws java.io.IOException
        Reads data into an array of bytes.
        Parameters:
        b - the array to write data to
        Returns:
        the number of bytes read, or -1 if end of input is reached
        Throws:
        java.io.IOException - if an I/O error has occurred

      • read

        public int read​(byte[] b,
                int off,
                int len)
         throws java.io.IOException
        Reads data into an array of bytes.
        Parameters:
        b - the array to write data to
        off - offset into the buffer to start filling at
        len - of bytes to read
        Returns:
        the number of bytes read, or -1 if end of input is reached
        Throws:
        java.io.IOException - if an I/O error has occurred

      • getStatisticsForCurrentEntry

        public InputStreamStatistics getStatisticsForCurrentEntry()
        Provides statistics for bytes read from the current entry.
        Returns:
        statistics for bytes read from the current entry
        Since:
        1.17

      • matches

        public static boolean matches​(byte[] signature,
                              int length)
        Checks if the signature matches what is expected for a 7z file.
        Parameters:
        signature - the bytes to check
        length - the number of bytes to check
        Returns:
        true, if this is the signature of a 7z archive.
        Since:
        1.8

      • toString

        public java.lang.String toString()
        Overrides:
        toString in class java.lang.Object

      • getDefaultName

        public java.lang.String getDefaultName()
        Derives a default file name from the archive name - if known.

        This implements the same heuristics the 7z tools use. In 7z's case if an archive contains entries without a name - i.e. SevenZArchiveEntry.getName() returns null - then its command line and GUI tools will use this default name when extracting the entries.

        Returns:
        null if the name of the archive is unknown. Otherwise if the name of the archive has got any extension, it is stripped and the remainder returned. Finally if the name of the archive hasn't got any extension then a ~ character is appended to the archive name.
        Since:
        1.19