FileInputStreamFileInputStreamFileOutputStreamGZIPOutputStream
Decompress a GZIP File in Java example
In the previous tutorial we saw how to compress a File with the GZIP method. In this tutorial we are going to see how to decompress the File that was compressed with the GZIP method.
Basically all you have to do to decompress a gzipped file is:
- Create a
FileInputStreamto the compressed File. - Create a
GZIPInputStreamto the aboveFileInputStream. - Create a
FileOutputStreamto the decompressed File. - Read the bytes from the compressed File using the
GZIPInputStreamand write them to the uncompressed File.
Let’s take a look at the code snippet that follows:
package com.javacodegeeks.java.core;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.util.zip.GZIPInputStream;
import java.util.zip.GZIPOutputStream;
public class CompressFileGzip {
public static void main(String[] args) {
String gzip_filepath = "C:\\Users\\nikos7\\Desktop\\files\\test.gzip";
String decopressed_filepath = "C:\\Users\\nikos7\\Desktop\\files\\test2.txt";
CompressFileGzip gZipFile = new CompressFileGzip();
gZipFile.unGunzipFile(gzip_filepath, decopressed_filepath);
}
public void unGunzipFile(String compressedFile, String decompressedFile) {
byte[] buffer = new byte[1024];
try {
FileInputStream fileIn = new FileInputStream(compressedFile);
GZIPInputStream gZIPInputStream = new GZIPInputStream(fileIn);
FileOutputStream fileOutputStream = new FileOutputStream(decompressedFile);
int bytes_read;
while ((bytes_read = gZIPInputStream.read(buffer)) > 0) {
fileOutputStream.write(buffer, 0, bytes_read);
}
gZIPInputStream.close();
fileOutputStream.close();
System.out.println("The file was decompressed successfully!");
} catch (IOException ex) {
ex.printStackTrace();
}
}
}Output:
The file was decompressed successfully!Here is the full interface to compress and decompress Files using the GZIP method:
package com.javacodegeeks.java.core;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.util.zip.GZIPInputStream;
import java.util.zip.GZIPOutputStream;
public class CompressFileGzip {
public static void main(String[] args) {
String source_filepath = "C:\\Users\\nikos7\\Desktop\\files\\test.txt";
String gzip_filepath = "C:\\Users\\nikos7\\Desktop\\files\\test.gzip";
String decopressed_filepath = "C:\\Users\\nikos7\\Desktop\\files\\test2.txt";
CompressFileGzip gZipFile = new CompressFileGzip();
gZipFile.gzipFile(source_filepath, gzip_filepath);
gZipFile.unGunzipFile(gzip_filepath, decopressed_filepath);
}
public void gzipFile(String source_filepath, String destinaton_zip_filepath) {
byte[] buffer = new byte[1024];
try {
FileOutputStream fileOutputStream = new FileOutputStream(
destinaton_zip_filepath);
GZIPOutputStream gzipOuputStream = new GZIPOutputStream(
fileOutputStream);
FileInputStream fileInput = new FileInputStream(source_filepath);
int bytes_read;
while ((bytes_read = fileInput.read(buffer)) > 0) {
gzipOuputStream.write(buffer, 0, bytes_read);
}
fileInput.close();
gzipOuputStream.finish();
gzipOuputStream.close();
System.out.println("The file was compressed successfully!");
} catch (IOException ex) {
ex.printStackTrace();
}
}
public void unGunzipFile(String compressedFile, String decompressedFile) {
byte[] buffer = new byte[1024];
try {
FileInputStream fileIn = new FileInputStream(compressedFile);
GZIPInputStream gZIPInputStream = new GZIPInputStream(fileIn);
FileOutputStream fileOutputStream = new FileOutputStream(decompressedFile);
int bytes_read;
while ((bytes_read = gZIPInputStream.read(buffer)) > 0) {
fileOutputStream.write(buffer, 0, bytes_read);
}
gZIPInputStream.close();
fileOutputStream.close();
System.out.println("The file was decompressed successfully!");
} catch (IOException ex) {
ex.printStackTrace();
}
}
}Output:
The file was compressed successfully!
The file was decompressed successfully!
This was an example on how to decompress a compressed File with the GZIP method.
