ZipCompress.java Source code

Introduction

Here is the source code for ZipCompress.java

Source

// : 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
        }
    }
} ///:~