- 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.ZipInputStream.read() Method Example
Description
The java.util.zip.ZipInputStream.read(byte[] buf, int off, int len) method reads from the current ZIP entry into an array of bytes. If len is not zero, the method blocks until some input is available; otherwise, no bytes are read and 0 is returned.
Declaration
Following is the declaration for java.util.zip.ZipInputStream.read(byte[] buf, int off, int len) method.
public int read(byte[] buf, int off, int len) throws IOException
Parameters
buf − 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 read, or -1 if the end of the stream is reached.
Exceptions
NullPointerException − If buf is null.
IndexOutOfBoundsException − If off is negative, len is negative, or len is greater than buf.length - off.
ZipException − if a ZIP file error has occurred.
IOException − if an I/O error has occurred.
Pre-requisite
Create a file Hello.txt in D:> test > directory with the following content.
This is an example.
Example
The following example shows the usage of java.util.zip.ZipInputStream.read(byte[] buf, int off, int len) method.
package com.tutorialspoint; import java.io.FileInputStream; import java.io.FileOutputStream; import java.io.IOException; import java.util.Date; import java.util.zip.Adler32; import java.util.zip.CheckedOutputStream; import java.util.zip.ZipEntry; import java.util.zip.ZipInputStream; import java.util.zip.ZipOutputStream; public class ZipInputStreamDemo { private static String SOURCE_FILE = "D:\\test\\Hello.txt"; private static String TARGET_FILE = "D:\\test\\Hello.zip"; public static void main(String[] args) { try { createZipFile(); readZipFile(); } catch(IOException ioe) { System.out.println("IOException : " + ioe); } } private static void createZipFile() throws IOException{ FileOutputStream fout = new FileOutputStream(TARGET_FILE); CheckedOutputStream checksum = new CheckedOutputStream(fout, new Adler32()); ZipOutputStream zout = new ZipOutputStream(checksum); FileInputStream fin = new FileInputStream(SOURCE_FILE); ZipEntry zipEntry = new ZipEntry(SOURCE_FILE); zout.putNextEntry(zipEntry); int length; byte[] buffer = new byte[1024]; while((length = fin.read(buffer)) > 0) { zout.write(buffer, 0, length); } zout.closeEntry(); fin.close(); zout.close(); } private static void readZipFile() throws IOException{ ZipInputStream zin = new ZipInputStream(new FileInputStream(TARGET_FILE)); ZipEntry entry; while((entry = zin.getNextEntry())!=null){ System.out.printf("File: %s Modified on %TD %n", entry.getName(), new Date(entry.getTime())); extractFile(entry, zin); System.out.printf("Zip file %s extracted successfully.", SOURCE_FILE); zin.closeEntry(); } zin.close(); } private static void extractFile(final ZipEntry entry, ZipInputStream is) throws IOException { FileOutputStream fos = null; try { fos = new FileOutputStream(entry.getName()); final byte[] buf = new byte[1024]; int read = 0; int length; while ((length = is.read(buf, 0, buf.length)) >= 0) { fos.write(buf, 0, length); } } catch (IOException ioex) { fos.close(); } } }
Let us compile and run the above program, this will produce the following result −
File: D:\test\Hello.txt Modified on 05/22/17 Zip file D:\test\Hello.txt extracted successfully.Print