package org.kodejava.util.zip;
import java.io.*;
import java.util.zip.ZipInputStream;
import java.util.zip.ZipEntry;
import java.util.zip.CheckedInputStream;
import java.util.zip.Adler32;
public class UnzipWithChecksum {
public static void main(String[] args) throws Exception {
String zipName = "data-1.zip";
try (FileInputStream fis = new FileInputStream(zipName);
// Creating input stream that also maintains the checksum of
// the data which later can be used to validate data
// integrity.
CheckedInputStream checksum =
new CheckedInputStream(fis, new Adler32());
ZipInputStream zis =
new ZipInputStream(new BufferedInputStream(checksum))) {
ZipEntry entry;
// Read each entry from the ZipInputStream until no more entry
// found indicated by a null return value of the getNextEntry()
// method.
while ((entry = zis.getNextEntry()) != null) {
System.out.println("Unzipping: " + entry.getName());
int size;
byte[] buffer = new byte[1048];
try (FileOutputStream fos =
new FileOutputStream(entry.getName());
BufferedOutputStream bos =
new BufferedOutputStream(fos, buffer.length)) {
while ((size = zis.read(buffer, 0, buffer.length)) != -1) {
bos.write(buffer, 0, size);
}
bos.flush();
}
}
// Print out the checksum value
long value = checksum.getChecksum().getValue();
System.out.println("Checksum = " + value);
}
}
}
Tag Archives: ZipInputStream
How do I decompress a zip file using ZipInputStream?
The code below shows how to decompress and extract files from a zip archive. In the example we use the java.util.zip.ZipInputStream
class.
package org.kodejava.util.zip;
import java.io.*;
import java.util.zip.ZipInputStream;
import java.util.zip.ZipEntry;
public class UnzipDemo {
public static void main(String[] args) {
String zipName = "data.zip";
try (FileInputStream fis = new FileInputStream(zipName);
ZipInputStream zis =
new ZipInputStream(new BufferedInputStream(fis))) {
ZipEntry entry;
// Read each entry from the ZipInputStream until no
// more entry found indicated by a null return value
// of the getNextEntry() method.
while ((entry = zis.getNextEntry()) != null) {
System.out.println("Unzipping: " + entry.getName());
int size;
byte[] buffer = new byte[2048];
try (FileOutputStream fos =
new FileOutputStream(entry.getName());
BufferedOutputStream bos =
new BufferedOutputStream(fos, buffer.length)) {
while ((size = zis.read(buffer, 0, buffer.length)) != -1) {
bos.write(buffer, 0, size);
}
bos.flush();
}
}
} catch (IOException e) {
e.printStackTrace();
}
}
}