zip/compress a folder full of files on android

This code should do the trick.

Note: you must add file write permissions to your app by adding the WRITE_EXTERNAL_STORAGE permission to your manifest.xml file.

/* *  * Zips a file at a location and places the resulting zip file at the toLocation * Example: zipFileAtPath("downloads/myfolder", "downloads/myFolder.zip"); */public boolean zipFileAtPath(String sourcePath, String toLocation) {    final int BUFFER = 2048;    File sourceFile = new File(sourcePath);    try {        BufferedInputStream origin = null;        FileOutputStream dest = new FileOutputStream(toLocation);        ZipOutputStream out = new ZipOutputStream(new BufferedOutputStream(                dest));        if (sourceFile.isDirectory()) {            zipSubFolder(out, sourceFile, sourceFile.getParent().length());        } else {            byte data[] = new byte[BUFFER];            FileInputStream fi = new FileInputStream(sourcePath);            origin = new BufferedInputStream(fi, BUFFER);            ZipEntry entry = new ZipEntry(getLastPathComponent(sourcePath));            entry.setTime(sourceFile.lastModified()); // to keep modification time after unzipping            out.putNextEntry(entry);            int count;            while ((count = origin.read(data, 0, BUFFER)) != -1) {                out.write(data, 0, count);            }        }        out.close();    } catch (Exception e) {        e.printStackTrace();        return false;    }    return true;}/* *  * Zips a subfolder *  */private void zipSubFolder(ZipOutputStream out, File folder,        int basePathLength) throws IOException {    final int BUFFER = 2048;    File[] fileList = folder.listFiles();    BufferedInputStream origin = null;    for (File file : fileList) {        if (file.isDirectory()) {            zipSubFolder(out, file, basePathLength);        } else {            byte data[] = new byte[BUFFER];            String unmodifiedFilePath = file.getPath();            String relativePath = unmodifiedFilePath                    .substring(basePathLength);            FileInputStream fi = new FileInputStream(unmodifiedFilePath);            origin = new BufferedInputStream(fi, BUFFER);            ZipEntry entry = new ZipEntry(relativePath);            entry.setTime(file.lastModified()); // to keep modification time after unzipping            out.putNextEntry(entry);            int count;            while ((count = origin.read(data, 0, BUFFER)) != -1) {                out.write(data, 0, count);            }            origin.close();        }    }}/* * gets the last path component *  * Example: getLastPathComponent("downloads/example/fileToZip"); * Result: "fileToZip" */public String getLastPathComponent(String filePath) {    String[] segments = filePath.split("/");    if (segments.length == 0)        return "";    String lastPathComponent = segments[segments.length - 1];    return lastPathComponent;}

this is how I do it:

private static void zipFolder(String inputFolderPath, String outZipPath) {    try {        FileOutputStream fos = new FileOutputStream(outZipPath);        ZipOutputStream zos = new ZipOutputStream(fos);        File srcFile = new File(inputFolderPath);        File[] files = srcFile.listFiles();        Log.d("", "Zip directory: " + srcFile.getName());        for (int i = 0; i < files.length; i++) {            Log.d("", "Adding file: " + files[i].getName());            byte[] buffer = new byte[1024];            FileInputStream fis = new FileInputStream(files[i]);            zos.putNextEntry(new ZipEntry(files[i].getName()));            int length;            while ((length = fis.read(buffer)) > 0) {                zos.write(buffer, 0, length);            }            zos.closeEntry();            fis.close();        }        zos.close();    } catch (IOException ioe) {        Log.e("", ioe.getMessage());    }}

I have reworked the code from HailZeon to work properly under windows. Zip Entries must be closed before new ones are started and a starting "/" at entry names like "/file.txt" makes also problems

/** * Zips a Folder to "[Folder].zip" * @param toZipFolder Folder to be zipped * @return the resulting ZipFile */public static File zipFolder(File toZipFolder) {    File ZipFile = new File(toZipFolder.getParent(), format("%s.zip", toZipFolder.getName()));    try {        ZipOutputStream out = new ZipOutputStream(new FileOutputStream(ZipFile));        zipSubFolder(out, toZipFolder, toZipFolder.getPath().length());        out.close();        return ZipFile;    } catch (Exception ex) {        ex.printStackTrace();        return null;    }}/** * Main zip Function * @param out Target ZipStream * @param folder Folder to be zipped * @param basePathLength Length of original Folder Path (for recursion) */private static void zipSubFolder(ZipOutputStream out, File folder, int basePathLength) throws IOException {    final int BUFFER = 2048;    File[] fileList = folder.listFiles();    BufferedInputStream origin = null;    for (File file : fileList) {        if (file.isDirectory()) {            zipSubFolder(out, file, basePathLength);        } else {            byte data[] = new byte[BUFFER];            String unmodifiedFilePath = file.getPath();            String relativePath = unmodifiedFilePath.substring(basePathLength + 1);            FileInputStream fi = new FileInputStream(unmodifiedFilePath);            origin = new BufferedInputStream(fi, BUFFER);            ZipEntry entry = new ZipEntry(relativePath);            entry.setTime(file.lastModified()); // to keep modification time after unzipping            out.putNextEntry(entry);            int count;            while ((count = origin.read(data, 0, BUFFER)) != -1) {                out.write(data, 0, count);            }            origin.close();            out.closeEntry();        }    }}