Introduction to the String Decompression class library (Zip, GZIP, Quicklz, Snappy, LZF, Jzlib)

1, ZIP, GZIP computer file compression algorithm, JDK java.util.zip.* in the implementation. Mainly include Zipinputstream/zipoutputstream, Gzipinputstream/zipoutputstream.

2, Quicklz is known as the world's fastest compression library, and is also an open source compression library, which complies with the GPL 1, 2 or 3 protocol.

3, Snappy is a C + + compression and decompression of the development package, its goal is not to maximize compression, and incompatible with other compression formats. It is designed to provide high speed compression and reasonable compression rate. On the Core i7 processor in 64-bit mode, the compression speed of 250~500 MB per second is up. Widely used within Google, from BigTable to mapreduce and internal RPC systems.

4. LZF uses a hybrid encoding similar to LZ77 and LZSS for the string compression algorithm.

5, Jzlib is a pure Java open source decompression, compression package, and JDK zlib similar.

Introduction to pre-selection decompression class library use--zip

Compression

string s = "This is a string for testing";

Bytearrayoutputstream out = new Bytearrayoutputstream ();

Zipoutputstreamzout = new Zipoutputstream (out);

Zout.putnextentry (New ZipEntry ("0"));

Zout.write (S.getbytes ());

Zout.closeentry ();

byte[] Compressed = Out.tobytearray (); --Returns a byte array of the compressed string

Extract

Bytearrayoutputstream out = new Bytearrayoutputstream ();

Bytearrayinputstream in = new Bytearrayinputstream (compressed);

Zipinputstreamzin = new Zipinputstream (in);

Zin.getnextentry ();

byte[] buffer = new byte[1024];

Intoffset =-1;

while (offset = zin.read (buffer))! =-1) {

Out.write (buffer, 0, offset);

}

byte[] uncompressed = Out.tobytearray (); --Returns a byte array of the extracted string

Introduction to pre-selection decompression class library use--gzip

Compression

string s = "This is a string for testing";

Bytearrayoutputstream out = new Bytearrayoutputstream ();

Gzipoutputstream gout = new Gzipoutputstream (out);

Gout.write (S.getbytes ());

byte[] Compressed = Out.tobytearray (); --Returns a byte array of the compressed string

Extract

Bytearrayoutputstream out = new Bytearrayoutputstream ();

Bytearrayinputstream in = new Bytearrayinputstream (compressed);

Gzipinputstreamgzin =newgzipinputstream (in);

byte[] buffer = new byte[1024];

Intoffset =-1;

while (offset = gzin.read (buffer))! =-1) {

Out.write (buffer, 0, offset);

}

byte[] uncompressed = Out.tobytearray (); --Returns a byte array of the extracted string

Introduction to pre-selection decompression class library use--quicklz

Compression

string s = "This is a string for testing";

--level 1

Byte[] Compressed =quicklz.compress (S.getbytes (), 1); --Returns a byte array of the compressed string

--level3

Byte[] Compressed =quicklz.compress (S.getbytes (), 3); --Returns a byte array of the compressed string

Extract

Byte[] Uncompressed =quicklz.decompress (compressed); --Returns a byte array of the extracted string

Introduction to pre-selection decompression class library use--snappy

Compression

string s = "This is a string for testing";

Byte[] Compressed =snappy.compress (S.getbytes ()); --Returns a byte array of the compressed string

Extract

Byte[] Uncompressed =snappy.uncompress (compressed); --Returns a byte array of the extracted string

Introduction to the use of preselection decompression class library--LZF

Compression

string s = "This is a string for testing";

byte[] Compressed = Lzfencoder.encode (S.getbytes ()); --Returns a byte array of the compressed string

Extract

byte[] uncompressed = Lzfdecoder. Decode   (compressed); --Returns a byte array of the extracted string

Introduction to the use of preselection decompression class library--Jzlib

Compression

string s = "This is a string for testing";

Bytearrayoutputstream out = new Bytearrayoutputstream ();

Deflateroutputstreamdout = new Deflateroutputstream (out);

Dout.write (S.getbytes ());

Dout.close (); --Need to close first

byte[] Compressed = Out.tobytearray (); --Returns a byte array of the compressed string

Extract

Bytearrayoutputstream out= new Bytearrayoutputstream ();

Bytearrayinputstream in = new Bytearrayinputstream (COMPRESSEDSTR);

Inflaterinputstream input = new Inflaterinputstream (in);

byte[] buffer = new byte[1024];

Intoffset =-1;

while (offset = input.read (buffer))! =-1) {

Out.write (buffer, 0, offset);

}

Out.close (); --Need to close first

byte[] uncompressed = Out.tobytearray (); --Returns a byte array of the extracted string

Transferred from: http://blog.csdn.net/mcpang/article/details/41141261

Introduction to the String Decompression class library (Zip, GZIP, Quicklz, Snappy, LZF, Jzlib)