java read a file inside a zip file code example

Example: reading zip file in java

import java.io.BufferedInputStream;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.util.Date;
import java.util.Enumeration;
import java.util.zip.ZipEntry;
import java.util.zip.ZipFile;
import java.util.zip.ZipInputStream;

/**
 * Java program to iterate and read file entries from Zip archive.
 * This program demonstrate two ways to retrieve files from Zip using ZipFile and by using ZipInputStream class.
 * @author Javin
 */

public class ZipFileReader {

    // This Zip file contains 11 PNG images
    private static final String FILE_NAME = "C:\\temp\\pics.zip";
    private static final String OUTPUT_DIR = "C:\\temp\\Images\\";
    private static final int BUFFER_SIZE = 8192;

    public static void main(String args[]) throws IOException {

        // Prefer ZipFile over ZipInputStream
        readUsingZipFile();
    //  readUsingZipInputStream();

    }

    /*
     * Example of reading Zip archive using ZipFile class
     */

    private static void readUsingZipFile() throws IOException {
        final ZipFile file = new ZipFile(FILE_NAME);
        System.out.println("Iterating over zip file : " + FILE_NAME);

        try {
            final Enumeration<? extends ZipEntry> entries = file.entries();
            while (entries.hasMoreElements()) {
                final ZipEntry entry = entries.nextElement();
                System.out.printf("File: %s Size %d  Modified on %TD %n", entry.getName(), entry.getSize(), new Date(entry.getTime()));
                extractEntry(entry, file.getInputStream(entry));
            }
            System.out.printf("Zip file %s extracted successfully in %s", FILE_NAME, OUTPUT_DIR);
        } finally {
            file.close();
        }

    }

    /*
     * Example of reading Zip file using ZipInputStream in Java.
     */

    private static void readUsingZipInputStream() throws IOException {
        BufferedInputStream bis = new BufferedInputStream(new FileInputStream(FILE_NAME));
        final ZipInputStream is = new ZipInputStream(bis);

        try {
            ZipEntry entry;
            while ((entry = is.getNextEntry()) != null) {
                System.out.printf("File: %s Size %d  Modified on %TD %n", entry.getName(), entry.getSize(), new Date(entry.getTime()));
                extractEntry(entry, is);
            }
        } finally {
            is.close();
        }

    }

    /*
     * Utility method to read  data from InputStream
     */

    private static void extractEntry(final ZipEntry entry, InputStream is) throws IOException {
        String exractedFile = OUTPUT_DIR + entry.getName();
        FileOutputStream fos = null;

        try {
            fos = new FileOutputStream(exractedFile);
            final byte[] buf = new byte[BUFFER_SIZE];
            int read = 0;
            int length;

            while ((length = is.read(buf, 0, buf.length)) >= 0) {
                fos.write(buf, 0, length);
            }

        } catch (IOException ioex) {
            fos.close();
        }

    }

}

Output:
Iterating over zip file : C:\temp\pics.zip
File: Image  (11).png Size 21294  Modified on 10/24/13
File: Image  (1).png Size 22296  Modified on 11/19/13
File: Image  (2).png Size 10458  Modified on 10/24/13
File: Image  (3).png Size 18425  Modified on 11/19/13
File: Image  (4).png Size 31888  Modified on 11/19/13
File: Image  (5).png Size 27454  Modified on 11/19/13
File: Image  (6).png Size 67608  Modified on 11/19/13
File: Image  (7).png Size 8659  Modified on 11/19/13
File: Image  (8).png Size 40015  Modified on 11/19/13
File: Image  (9).png Size 17062  Modified on 10/24/13
File: Image  (10).png Size 42467  Modified on 10/24/13
Zip file C:\temp\pics.zip extracted successfully in C:\temp\Images\