Mega Code Archive
Uses Zip compression to compress any number of files given on the command line
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// : c12:ZipCompress.java
// Uses Zip compression to compress any
// number of files given on the command line.
// {Args: ZipCompress.java}
// {Clean: test.zip}
// From 'Thinking in Java, 3rd ed.' (c) Bruce Eckel 2002
// www.BruceEckel.com. See copyright notice in CopyRight.txt.
import java.io.BufferedInputStream;
import java.io.BufferedOutputStream;
import java.io.BufferedReader;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.FileReader;
import java.io.IOException;
import java.util.Enumeration;
import java.util.zip.Adler32;
import java.util.zip.CheckedInputStream;
import java.util.zip.CheckedOutputStream;
import java.util.zip.ZipEntry;
import java.util.zip.ZipFile;
import java.util.zip.ZipInputStream;
import java.util.zip.ZipOutputStream;
public class ZipCompress {
// Throw exceptions to console:
public static void main(String[] args) throws IOException {
FileOutputStream f = new FileOutputStream("test.zip");
CheckedOutputStream csum = new CheckedOutputStream(f, new Adler32());
ZipOutputStream zos = new ZipOutputStream(csum);
BufferedOutputStream out = new BufferedOutputStream(zos);
zos.setComment("A test of Java Zipping");
// No corresponding getComment(), though.
for (int i = 0; i < args.length; i++) {
System.out.println("Writing file " + args[i]);
BufferedReader in = new BufferedReader(new FileReader(args[i]));
zos.putNextEntry(new ZipEntry(args[i]));
int c;
while ((c = in.read()) != -1)
out.write(c);
in.close();
}
out.close();
// Checksum valid only after the file has been closed!
System.out.println("Checksum: " + csum.getChecksum().getValue());
// Now extract the files:
System.out.println("Reading file");
FileInputStream fi = new FileInputStream("test.zip");
CheckedInputStream csumi = new CheckedInputStream(fi, new Adler32());
ZipInputStream in2 = new ZipInputStream(csumi);
BufferedInputStream bis = new BufferedInputStream(in2);
ZipEntry ze;
while ((ze = in2.getNextEntry()) != null) {
System.out.println("Reading file " + ze);
int x;
while ((x = bis.read()) != -1)
System.out.write(x);
}
System.out.println("Checksum: " + csumi.getChecksum().getValue());
bis.close();
// Alternative way to open and read zip files:
ZipFile zf = new ZipFile("test.zip");
Enumeration e = zf.entries();
while (e.hasMoreElements()) {
ZipEntry ze2 = (ZipEntry) e.nextElement();
System.out.println("File: " + ze2);
// ... and extract the data as before
}
}
} ///:~
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