- 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.DeflaterInputStream.read() Method Example
Description
The java.util.zip.DeflaterInputStream.read(byte[] b, int off, int len) method reads a single byte of compressed data from the input stream. This method will block until some input can be read and compressed.
Declaration
Following is the declaration for java.util.zip.DeflaterInputStream.read(byte[] b, int off, int len) method.
public int read(byte[] b, int off, int len) throws IOException
Parameters
b − buffer into which the data is read.
off − starting offset of the data within b.
len − maximum number of compressed bytes to read into b.
Returns
the actual number of bytes read, or -1 if the end of the uncompressed input stream is reached.
Exceptions
IndexOutOfBoundsException − if len > b.length - off.
IOException − if an I/O error occurs or if this stream is already closed.
Example
The following example shows the usage of java.util.zip.DeflaterInputStream.read(byte[] b, int off, int len) method.
package com.tutorialspoint; import java.io.ByteArrayInputStream; import java.io.IOException; import java.util.zip.DataFormatException; import java.util.zip.Deflater; import java.util.zip.InflaterInputStream; public class DeflaterInputStreamDemo { public static void main(String[] args) throws DataFormatException, IOException { 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;"; System.out.println("Original Message length : " + message.length()); byte[] input = message.getBytes("UTF-8"); int length = message.length(); // Compress the bytes byte[] output = new byte[1024]; Deflater deflater = new Deflater(); deflater.setInput(input); deflater.finish(); int compressedDataLength = deflater.deflate(output,0 , output.length, Deflater.NO_FLUSH); System.out.println("Total uncompressed bytes input :" + deflater.getTotalIn()); System.out.println("Compressed Message Checksum :" + deflater.getAdler()); deflater.finished(); System.out.println("Compressed Message length : " + compressedDataLength); ByteArrayInputStream bin = new ByteArrayInputStream(output); InflaterInputStream inflaterInputStream = new InflaterInputStream(bin); byte[] result = new byte[1024]; inflaterInputStream.read(result,0,result.length); inflaterInputStream.close(); // Decode the bytes into a String String message1 = new String(result,0, length,"UTF-8"); System.out.println(message.equals(message1)); } }
Let us compile and run the above program, this will produce the following result −
Original Message length : 300 Total uncompressed bytes input :300 Compressed Message Checksum :368538129 Compressed Message length : 42 truePrint