- java.util.zip Package Classes
- java.util.zip - Home
- java.util.zip - Adler32
- java.util.zip - CheckedInputStream
- java.util.zip - CheckedOutputStream
- java.util.zip - CRC32
- java.util.zip - Deflater
- java.util.zip - DeflaterInputStream
- java.util.zip - DeflaterOutputStream
- java.util.zip - GZIPInputStream
- java.util.zip - GZIPOutputStream
- java.util.zip - Inflater
- java.util.zip - InflaterInputStream
- java.util.zip - InflaterOutputStream
- java.util.zip - ZipEntry
- java.util.zip - ZipFile
- java.util.zip - ZipInputStream
- java.util.zip - ZipOutputStream
- java.util.zip Package Extras
- java.util.zip - Exceptions
- java.util.zip - Error
- java.util.zip Useful Resources
- java.util.zip - Quick Guide
- java.util.zip - Useful Resources
- java.util.zip - Discussion
java.util.zip.Inflater.setDictionary() Method Example
Description
The java.util.zip.Inflater.setDictionary(byte[] b, int off, int len) method sets the preset dictionary to the given array of bytes. Should be called when inflate() returns 0 and needsDictionary() returns true indicating that a preset dictionary is required. The method getAdler() can be used to get the Adler-32 value of the dictionary needed.
Declaration
Following is the declaration for java.util.zip.Inflater.setDictionary(byte[] b, int off, int len) method.
public void setDictionary(byte[] b, int off, int len)
Parameters
b − the dictionary data bytes.
off − the start offset of the data.
len − the length of the data.
Example
The following example shows the usage of java.util.zip.Inflater.setDictionary(byte[] b, int off, int len) method.
package com.tutorialspoint; import java.io.UnsupportedEncodingException; import java.util.zip.DataFormatException; import java.util.zip.Deflater; import java.util.zip.Inflater; public class InflaterDemo { public static void main(String[] args) throws DataFormatException, UnsupportedEncodingException { String message = "Welcome to TutorialsPoint.com;" +"Welcome to TutorialsPoint.com;" +"Welcome to TutorialsPoint.com;" +"Welcome to TutorialsPoint.com;" +"Welcome to TutorialsPoint.com;" +"Welcome to TutorialsPoint.com;" +"Welcome to TutorialsPoint.com;" +"Welcome to TutorialsPoint.com;" +"Welcome to TutorialsPoint.com;" +"Welcome to TutorialsPoint.com;"; String dictionary = "Welcome"; System.out.println("Original Message length : " + message.length()); byte[] input = message.getBytes("UTF-8"); // Compress the bytes byte[] output = new byte[1024]; Deflater deflater = new Deflater(); deflater.setDictionary(dictionary.getBytes("UTF-8"),0, dictionary.length()); deflater.setInput(input); deflater.finish(); int compressedDataLength = deflater.deflate(output,0 , output.length, Deflater.NO_FLUSH); System.out.println("Total uncompressed bytes output :" + deflater.getTotalOut()); System.out.println("Compressed Message Checksum :" + deflater.getAdler()); deflater.finished(); System.out.println("Compressed Message length : " + compressedDataLength); // Decompress the bytes Inflater inflater = new Inflater(); inflater.setInput(output, 0, compressedDataLength); byte[] result = new byte[1024]; int resultLength = inflater.inflate(result); if(inflater.needsDictionary()){ inflater.setDictionary(dictionary.getBytes("UTF-8"),0, dictionary.length()); resultLength = inflater.inflate(result); } inflater.finished(); // Decode the bytes into a String message = new String(result, 0, resultLength, "UTF-8"); System.out.println("UnCompressed Message Checksum :" + inflater.getAdler()); System.out.println("UnCompressed Message length : " + message.length()); } }
Let us compile and run the above program, this will produce the following result −
Original Message length : 300 Total uncompressed bytes output :42 Compressed Message Checksum :368538129 Compressed Message length : 42 UnCompressed Message Checksum :368538129 UnCompressed Message length : 300Print
javazip_inflater.htm
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