Develop Reference

How to programmatically zip a file in Android?

I know this question already exists, but I'm not sure how to implement it in my case...
First I created an DataOutuputStream that will write in a file with .uedl extension:
private static DataOutputStream os;
public static final String BASE_PATH = Environment.getExternalStorageDirectory().getAbsolutePath() + "/myApp/logs/"
public static void startReceiveLogs() {
if (debugBaudRate > -1) {
mReadFlag = true;
String time = TimeUtils.getCurrentTime(TimeZone.getDefault());
try {
os = new DataOutputStream(new FileOutputStream(BASE_PATH + time + "_logs.uedl"));
} catch (FileNotFoundException e) {
e.printStackTrace();
}
mReceiveLogsThread = new Thread(new ReceiveLogsThread());
mReceiveLogsThread.start();
}
}
Here is the writing stuff:
public void run() {
byte[] rbuf = new byte[64];
while (mReadFlag) {
try {
int len = mSerial.readLog(rbuf, mSerialPortLog);
if (len > 0) {
os.write(rbuf, 0, len);
}
} catch (NullPointerException e1) {
e1.printStackTrace();
} catch (Exception e) {
e.printStackTrace();
}
}
}
Once this thread stops running, I'd like to compress that file at the same path.

You try this it will help for you
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;
}
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();
}
}
}
public String getLastPathComponent(String filePath) {
String[] segments = filePath.split("/");
if (segments.length == 0)
return "";
String lastPathComponent = segments[segments.length - 1];
return lastPathComponent;
}

Android ZIP folders

I use this code to ZIP folders including inner folders :
public boolean zipFileAtPath(String sourcePath, String toLocation) {
// ArrayList<String> contentList = new ArrayList<String>();
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));
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;
}
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);
Log.i("ZIP SUBFOLDER", "Relative Path : " + relativePath);
FileInputStream fi = new FileInputStream(unmodifiedFilePath);
origin = new BufferedInputStream(fi, BUFFER);
ZipEntry entry = new ZipEntry(relativePath);
out.putNextEntry(entry);
int count;
while ((count = origin.read(data, 0, BUFFER)) != -1) {
out.write(data, 0, count);
}
origin.close();
}
}
}
public String getLastPathComponent(String filePath) {
String[] segments = filePath.split("/");
String lastPathComponent = segments[segments.length - 1];
return lastPathComponent;
}
It works fine when folder looks like :
Folder
txt file
jpg file
txt file
It also works fine when folder looks like :
Folder
txt file
Folder
txt file
txt file
However in this case :
Folder
txt file
Folder
txt file
jpg file
txt file
it starts endless loop, when ZIP file continuously increases.
I noted, that it happens because this loop :
private void zipSubFolder(ZipOutputStream out, File folder,
int basePathLength) throws IOException {
.....
while ((count = origin.read(data, 0, BUFFER)) != -1) {
out.write(data, 0, count);
}
....
}
doesn't stop in the case, described above.
Any ideas why this can happen ? Thanks )

Here is the solution.
I save ZIP file inside the same folder, that is zipped. So it starts to zip the ZIP file itself, saving new ZIP file inside again and again and again.
Not sure, if it's clear, but anyway, pay attention where do you save ZIP file.

Ways to compress resources and/or files in Asset folders?

I am approaching finishing my application. My asset folder has over 20 PDF files in it, and obviously they are taking up quite a bit of space. Is there a way I can compress these files to make the Application smaller? What are other good techniques for checking / lowering memory consumption in my code / throughout my project? Thanks in advance for any input.

You could zip your files then decrompress when needed
Here's a tutorial Zip programmatically with Android
Check the java.util.zip class , it provides both zip & gzip functionality for compression and decompression.
You could also download the pdfs from another site once the application is installed
Or This Should work:
/*
*
* 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) {
// ArrayList<String> contentList = new ArrayList<String>();
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));
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);
Log.i("ZIP SUBFOLDER", "Relative Path : " + relativePath);
FileInputStream fi = new FileInputStream(unmodifiedFilePath);
origin = new BufferedInputStream(fi, BUFFER);
ZipEntry entry = new ZipEntry(relativePath);
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("/");
String lastPathComponent = segments[segments.length - 1];
return lastPathComponent;
}

Android - some unzipped files have 0 size (are empty)

i'm facing a problem with unzipping files in Android. Here is the code snippet:
public void unzip() {
try {
FileInputStream fin = new FileInputStream(_zipFile);
BufferedInputStream in = new BufferedInputStream(fin);
ZipInputStream zin = new ZipInputStream(in);
ZipEntry ze = null;
while ((ze = zin.getNextEntry()) != null) {
Log.v("Decompress", "Unzipping " + ze.getName());
if(ze.isDirectory()) {
_dirChecker(ze.getName());
} else {
FileOutputStream fout = new FileOutputStream(_location + ze.getName());
BufferedOutputStream out = new BufferedOutputStream(fout);
byte[] buffer = new byte[1024];
int length;
while ((length = zin.read(buffer,0,1024)) >= 0) {
out.write(buffer,0,length);
}
/* while ((length = zin.read(buffer))>0) {
out.write(buffer, 0, length);
}*/
/*for (int c = zin.read(); c != -1; c = zin.read()) {
fout.write(c);
}*/
zin.closeEntry();
fout.close();
}
}
zin.close();
} catch(Exception e) {
Log.e("Decompress", "unzip", e);
}
}
Smaller files (smaller than 10kB) are unzipped like empty - size 0 (html files, .jpg). Other files are ok. If I use this same code, but without buffers all the files are ok - ofcourse, unzipping without buffers is out of the question since it runs too long. Files are stored on SD card on real device. I have already tried setting smaller buffer size ( even new byte[2]). Thanks in advance...

Try this code instead,
public void doUnzip(String inputZipFile, String destinationDirectory)
throws IOException {
int BUFFER = 2048;
List zipFiles = new ArrayList();
File sourceZipFile = new File(inputZip);
File unzipDestinationDirectory = new File(destinationDirectory);
unzipDestinationDirectory.mkdir();
ZipFile zipFile;
// Open Zip file for reading
zipFile = new ZipFile(sourceZipFile, ZipFile.OPEN_READ);
// Create an enumeration of the entries in the zip file
Enumeration zipFileEntries = zipFile.entries();
// Process each entry
while (zipFileEntries.hasMoreElements()) {
// grab a zip file entry
ZipEntry entry = (ZipEntry) zipFileEntries.nextElement();
String currentEntry = entry.getName();
File destFile = new File(unzipDestinationDirectory, currentEntry);
// destFile = new File(unzipDestinationDirectory, destFile.getName());
if (currentEntry.endsWith(".zip")) {
zipFiles.add(destFile.getAbsolutePath());
}
// grab file's parent directory structure
File destinationParent = destFile.getParentFile();
// create the parent directory structure if needed
destinationParent.mkdirs();
try {
// extract file if not a directory
if (!entry.isDirectory()) {
BufferedInputStream is =
new BufferedInputStream(zipFile.getInputStream(entry));
int currentByte;
// establish buffer for writing file
byte data[] = new byte[BUFFER];
// write the current file to disk
FileOutputStream fos = new FileOutputStream(destFile);
BufferedOutputStream dest =
new BufferedOutputStream(fos, BUFFER);
// read and write until last byte is encountered
while ((currentByte = is.read(data, 0, BUFFER)) != -1) {
dest.write(data, 0, currentByte);
}
dest.flush();
dest.close();
is.close();
}
} catch (IOException ioe) {
ioe.printStackTrace();
}
}
zipFile.close();
for (Iterator iter = zipFiles.iterator(); iter.hasNext();) {
String zipName = (String)iter.next();
doUnzip(
zipName,
destinationDirectory +
File.separatorChar +
zipName.substring(0,zipName.lastIndexOf(".zip"))
);
}
}

How to zip and unzip the files?

How to zip and unzip the files which are all already in DDMS : data/data/mypackage/files/ I need a simple example for that. I've already search related to zip and unzip. But, no one example available for me. Can anyone tell some example. Advance Thanks.

Take a look at java.util.zip.* classes for zip functionality. I've done some basic zip/unzip code, which I've pasted below. Hope it helps.
public static void zip(String[] files, String zipFile) throws IOException {
BufferedInputStream origin = null;
ZipOutputStream out = new ZipOutputStream(new BufferedOutputStream(new FileOutputStream(zipFile)));
try {
byte data[] = new byte[BUFFER_SIZE];
for (int i = 0; i < files.length; i++) {
FileInputStream fi = new FileInputStream(files[i]);
origin = new BufferedInputStream(fi, BUFFER_SIZE);
try {
ZipEntry entry = new ZipEntry(files[i].substring(files[i].lastIndexOf("/") + 1));
out.putNextEntry(entry);
int count;
while ((count = origin.read(data, 0, BUFFER_SIZE)) != -1) {
out.write(data, 0, count);
}
}
finally {
origin.close();
}
}
}
finally {
out.close();
}
}
public static void unzip(String zipFile, String location) throws IOException {
try {
File f = new File(location);
if(!f.isDirectory()) {
f.mkdirs();
}
ZipInputStream zin = new ZipInputStream(new FileInputStream(zipFile));
try {
ZipEntry ze = null;
while ((ze = zin.getNextEntry()) != null) {
String path = location + ze.getName();
if (ze.isDirectory()) {
File unzipFile = new File(path);
if(!unzipFile.isDirectory()) {
unzipFile.mkdirs();
}
}
else {
FileOutputStream fout = new FileOutputStream(path, false);
try {
for (int c = zin.read(); c != -1; c = zin.read()) {
fout.write(c);
}
zin.closeEntry();
}
finally {
fout.close();
}
}
}
}
finally {
zin.close();
}
}
catch (Exception e) {
Log.e(TAG, "Unzip exception", e);
}
}

The zip function brianestey provided works well, but the unzip function is very slow due to reading one byte at a time. Here is a modified version of his unzip function that utilizes a buffer and is much faster.
/**
* Unzip a zip file. Will overwrite existing files.
*
* #param zipFile Full path of the zip file you'd like to unzip.
* #param location Full path of the directory you'd like to unzip to (will be created if it doesn't exist).
* #throws IOException
*/
public static void unzip(String zipFile, String location) throws IOException {
int size;
byte[] buffer = new byte[BUFFER_SIZE];
try {
if ( !location.endsWith(File.separator) ) {
location += File.separator;
}
File f = new File(location);
if(!f.isDirectory()) {
f.mkdirs();
}
ZipInputStream zin = new ZipInputStream(new BufferedInputStream(new FileInputStream(zipFile), BUFFER_SIZE));
try {
ZipEntry ze = null;
while ((ze = zin.getNextEntry()) != null) {
String path = location + ze.getName();
File unzipFile = new File(path);
if (ze.isDirectory()) {
if(!unzipFile.isDirectory()) {
unzipFile.mkdirs();
}
} else {
// check for and create parent directories if they don't exist
File parentDir = unzipFile.getParentFile();
if ( null != parentDir ) {
if ( !parentDir.isDirectory() ) {
parentDir.mkdirs();
}
}
// unzip the file
FileOutputStream out = new FileOutputStream(unzipFile, false);
BufferedOutputStream fout = new BufferedOutputStream(out, BUFFER_SIZE);
try {
while ( (size = zin.read(buffer, 0, BUFFER_SIZE)) != -1 ) {
fout.write(buffer, 0, size);
}
zin.closeEntry();
}
finally {
fout.flush();
fout.close();
}
}
}
}
finally {
zin.close();
}
}
catch (Exception e) {
Log.e(TAG, "Unzip exception", e);
}
}

Using File instead of the file path String.
This answer is based off of #brianestey's excellent answer.
I have modified his zip method to accept a list of Files instead of file paths and an output zip File instead of a filepath, which might be helpful to others if that's what they're dealing with.
public static void zip( List<File> files, File zipFile ) throws IOException {
final int BUFFER_SIZE = 2048;
BufferedInputStream origin = null;
ZipOutputStream out = new ZipOutputStream(new BufferedOutputStream(new FileOutputStream(zipFile)));
try {
byte data[] = new byte[BUFFER_SIZE];
for ( File file : files ) {
FileInputStream fileInputStream = new FileInputStream( file );
origin = new BufferedInputStream(fileInputStream, BUFFER_SIZE);
String filePath = file.getAbsolutePath();
try {
ZipEntry entry = new ZipEntry( filePath.substring( filePath.lastIndexOf("/") + 1 ) );
out.putNextEntry(entry);
int count;
while ((count = origin.read(data, 0, BUFFER_SIZE)) != -1) {
out.write(data, 0, count);
}
}
finally {
origin.close();
}
}
}
finally {
out.close();
}
}

This answer is based of brianestey, Ben, Giacomo Mattiuzzi, Joshua Pinter.
Functions rewritten to Kotlin and added functions for working with Uri.
import android.content.Context
import android.net.Uri
import java.io.*
import java.util.zip.ZipEntry
import java.util.zip.ZipInputStream
import java.util.zip.ZipOutputStream
private const val MODE_WRITE = "w"
private const val MODE_READ = "r"
fun zip(zipFile: File, files: List<File>) {
ZipOutputStream(BufferedOutputStream(FileOutputStream(zipFile))).use { outStream ->
zip(outStream, files)
}
}
fun zip(context: Context, zipFile: Uri, files: List<File>) {
context.contentResolver.openFileDescriptor(zipFile, MODE_WRITE).use { descriptor ->
descriptor?.fileDescriptor?.let {
ZipOutputStream(BufferedOutputStream(FileOutputStream(it))).use { outStream ->
zip(outStream, files)
}
}
}
}
private fun zip(outStream: ZipOutputStream, files: List<File>) {
files.forEach { file ->
outStream.putNextEntry(ZipEntry(file.name))
BufferedInputStream(FileInputStream(file)).use { inStream ->
inStream.copyTo(outStream)
}
}
}
fun unzip(zipFile: File, location: File) {
ZipInputStream(BufferedInputStream(FileInputStream(zipFile))).use { inStream ->
unzip(inStream, location)
}
}
fun unzip(context: Context, zipFile: Uri, location: File) {
context.contentResolver.openFileDescriptor(zipFile, MODE_READ).use { descriptor ->
descriptor?.fileDescriptor?.let {
ZipInputStream(BufferedInputStream(FileInputStream(it))).use { inStream ->
unzip(inStream, location)
}
}
}
}
private fun unzip(inStream: ZipInputStream, location: File) {
if (location.exists() && !location.isDirectory)
throw IllegalStateException("Location file must be directory or not exist")
if (!location.isDirectory) location.mkdirs()
val locationPath = location.absolutePath.let {
if (!it.endsWith(File.separator)) "$it${File.separator}"
else it
}
var zipEntry: ZipEntry?
var unzipFile: File
var unzipParentDir: File?
while (inStream.nextEntry.also { zipEntry = it } != null) {
unzipFile = File(locationPath + zipEntry!!.name)
if (zipEntry!!.isDirectory) {
if (!unzipFile.isDirectory) unzipFile.mkdirs()
} else {
unzipParentDir = unzipFile.parentFile
if (unzipParentDir != null && !unzipParentDir.isDirectory) {
unzipParentDir.mkdirs()
}
BufferedOutputStream(FileOutputStream(unzipFile)).use { outStream ->
inStream.copyTo(outStream)
}
}
}
}