Class InflaterInputStream

All Implemented Interfaces:
Closeable, AutoCloseable
Direct Known Subclasses:
GZIPInputStream, ZipInputStream

public class InflaterInputStream extends FilterInputStream
This class implements a stream filter for uncompressing data in the "deflate" compression format. It is also used as the basis for other decompression filters, such as GZIPInputStream.

Unless otherwise noted, passing a null argument to a constructor or method in this class will cause a NullPointerException to be thrown.

Since:
1.1
See Also:
  • Field Summary

    Fields
    Modifier and Type
    Field
    Description
    protected byte[]
    Input buffer for decompression.
    protected Inflater
    Decompressor for this stream.
    protected int
    The total number of bytes read into the input buffer.

    Fields declared in class java.io.FilterInputStream

    in
  • Constructor Summary

    Constructors
    Constructor
    Description
    Creates a new input stream with a default decompressor and buffer size.
    Creates a new input stream with the specified decompressor and a default buffer size.
    Creates a new input stream with the specified decompressor and buffer size.
  • Method Summary

    Modifier and Type
    Method
    Description
    int
    Returns 0 after EOF has been reached, otherwise always return 1.
    void
    Closes this input stream and releases any system resources associated with the stream.
    protected void
    Fills input buffer with more data to decompress.
    void
    mark(int readlimit)
    Marks the current position in this input stream.
    boolean
    Tests if this input stream supports the mark and reset methods.
    int
    Reads a byte of uncompressed data.
    int
    read(byte[] b, int off, int len)
    Reads uncompressed data into an array of bytes, returning the number of inflated bytes.
    void
    Repositions this stream to the position at the time the mark method was last called on this input stream.
    long
    skip(long n)
    Skips specified number of bytes of uncompressed data.

    Methods declared in class java.io.FilterInputStream

    read

    Methods declared in class java.lang.Object

    clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
  • Field Details

    • inf

      protected Inflater inf
      Decompressor for this stream.
    • buf

      protected byte[] buf
      Input buffer for decompression.
    • len

      protected int len
      The total number of bytes read into the input buffer.
  • Constructor Details

    • InflaterInputStream

      public InflaterInputStream(InputStream in, Inflater inf, int size)
      Creates a new input stream with the specified decompressor and buffer size.
      Parameters:
      in - the input stream
      inf - the decompressor ("inflater")
      size - the input buffer size
      Throws:
      IllegalArgumentException - if size <= 0
    • InflaterInputStream

      public InflaterInputStream(InputStream in, Inflater inf)
      Creates a new input stream with the specified decompressor and a default buffer size.
      Parameters:
      in - the input stream
      inf - the decompressor ("inflater")
    • InflaterInputStream

      public InflaterInputStream(InputStream in)
      Creates a new input stream with a default decompressor and buffer size.
      Parameters:
      in - the input stream
  • Method Details

    • read

      public int read() throws IOException
      Reads a byte of uncompressed data. This method will block until enough input is available for decompression.
      Overrides:
      read in class FilterInputStream
      Returns:
      the byte read, or -1 if end of compressed input is reached
      Throws:
      IOException - if an I/O error has occurred
      See Also:
    • read

      public int read(byte[] b, int off, int len) throws IOException
      Reads uncompressed data into an array of bytes, returning the number of inflated bytes. If len is not zero, the method will block until some input can be decompressed; otherwise, no bytes are read and 0 is returned.

      If this method returns a nonzero integer n then buf[off] through buf[off+n-1] contain the uncompressed data. The content of elements buf[off+n] through buf[off+len-1] is undefined, contrary to the specification of the InputStream superclass, so an implementation is free to modify these elements during the inflate operation. If this method returns -1 or throws an exception then the content of buf[off] through buf[off+len -1] is undefined.

      Overrides:
      read in class FilterInputStream
      Parameters:
      b - the buffer into which the data is read
      off - the start offset in the destination array b
      len - the maximum number of bytes read
      Returns:
      the actual number of bytes inflated, or -1 if the end of the compressed input is reached or a preset dictionary is needed
      Throws:
      IndexOutOfBoundsException - If off is negative, len is negative, or len is greater than b.length - off
      ZipException - if a ZIP format error has occurred
      IOException - if an I/O error has occurred
      See Also:
    • available

      public int available() throws IOException
      Returns 0 after EOF has been reached, otherwise always return 1.

      Programs should not count on this method to return the actual number of bytes that could be read without blocking.

      Overrides:
      available in class FilterInputStream
      Returns:
      1 before EOF and 0 after EOF.
      Throws:
      IOException - if an I/O error occurs.
    • skip

      public long skip(long n) throws IOException
      Skips specified number of bytes of uncompressed data. This method may block until the specified number of bytes are skipped or end of stream is reached.
      Overrides:
      skip in class FilterInputStream
      Implementation Note:
      This method skips at most Integer.MAX_VALUE bytes.
      Parameters:
      n - the number of bytes to skip. If n is zero then no bytes are skipped.
      Returns:
      the actual number of bytes skipped, which might be zero
      Throws:
      IOException - if an I/O error occurs or if this stream is already closed
      IllegalArgumentException - if n < 0
      See Also:
    • close

      public void close() throws IOException
      Closes this input stream and releases any system resources associated with the stream.
      Specified by:
      close in interface AutoCloseable
      Specified by:
      close in interface Closeable
      Overrides:
      close in class FilterInputStream
      Throws:
      IOException - if an I/O error has occurred
      See Also:
    • fill

      protected void fill() throws IOException
      Fills input buffer with more data to decompress.
      Implementation Requirements:
      This method will read up to buf.length bytes into the input buffer, buf, starting at element 0. The len field will be set to the number of bytes read.
      Throws:
      IOException - if an I/O error has occurred
      EOFException - if the end of input stream has been reached unexpectedly
    • markSupported

      public boolean markSupported()
      Tests if this input stream supports the mark and reset methods. The markSupported method of InflaterInputStream returns false.
      Overrides:
      markSupported in class FilterInputStream
      Returns:
      a boolean indicating if this stream type supports the mark and reset methods.
      See Also:
    • mark

      public void mark(int readlimit)
      Marks the current position in this input stream.
      Overrides:
      mark in class FilterInputStream
      Implementation Requirements:
      The mark method of InflaterInputStream does nothing.
      Parameters:
      readlimit - the maximum limit of bytes that can be read before the mark position becomes invalid.
      See Also:
    • reset

      public void reset() throws IOException
      Repositions this stream to the position at the time the mark method was last called on this input stream.
      Overrides:
      reset in class FilterInputStream
      Implementation Requirements:
      The method reset for class InflaterInputStream does nothing except throw an IOException.
      Throws:
      IOException - if this method is invoked.
      See Also: