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Web Service to Display a PDF, deleting the file once displayed

I am attempting to display PDFs to the user in their browser using a web service. Once they pass in the URL containing the variables needed. My program first downloads the PDF to local storage then proceeds to copy it to the stream and displays it. Once the viewer is able to view the PDF we wish to delete the file locally so that we do not wind up storing every file searched for. I have managed to accomplish most of this task however I am having issues deleting the file once it is displayed to the user.
Even when I attempt to manually delete the file I receive the "Currently in use in the Java SE Binary" message
Code below:
File testFile = new File("C:\\Users\\stebela\\workspace\\my-app\\invoice"+invNum+".pdf");
try
{
ServletOutputStream os = res.raw().getOutputStream();
FileInputStream inputStr = new FileInputStream(testFile);
IOUtils.copy(inputStr, os);
os.close();
inputStr.close();
//finished settings
res.status(200);
testFile.delete();
} catch (IOException e)
{
System.out.println(e.getMessage());
}

If you don't write to the file, you'r code should work.
If you call inputStr.close(); the file is no longer used by java and it can be deleted.
Pleace check, if your file is not used by any other programm. It's the best if you reboot your PC.
If it still not works, it would be interessting to know, what res is and if your file get's sendet.
I've read this part of the documentation and i think this should solve your problem.
It reads the file into a String and change the header for png images. As the http Body it uses the String of the file.
Make sure, if you change the response type, you have to change the line res.type("image/png"); to the new one.
Here you find the most common ones
File testFile = null;
try {
testFile = new File("C:\\Users\\stebela\\workspace\\my-app\\invoice"+invNum+".png");
FileInputStream fin = new FileInputStream(testFile);
int charAsInt = 0;
String httpBody = "";
while((charAsInt = fin.read()) != -1){
httpBody +=(char)charAsInt;
}
fin.close();
res.body(httpBody);
res.type("image/png");
res.status(200);
testFile.delete();
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}

Java utility library for Nested ZIP file handling

I am aware that Oracle notes ZIP/GZIP file compressor/decompressor methods on their website. But I have a scenario where I need to scan and find out whether any nested ZIPs/RARs are involved. For example, the following case:
-MyFiles.zip
-MyNestedFiles.zip
-MyMoreNestedFiles.zip
-MoreProbably.zip
-Other_non_zips
-Other_non_zips
-Other_non_zips
I know that apache commons compress package and java.util.zip are the wideley used packages where commons compress actually caters for the missing features in java.util.zip e.g. some character setting whilst doing zipouts. But what I am not sure about is the utilities for recursing through nested zip files and the answers provided on SO are not very good examples of doing this. I tried the following code (which I got from Oracle blog), but as I suspected, the nested directory recursion fails because it simply cannot find the files:
public static void processZipFiles(String pathName) throws Exception{
ZipInputStream zis = null;
InputStream is = null;
try {
ZipFile zipFile = new ZipFile(new File(pathName));
String nestPathPrefix = zipFile.getName().substring(0, zipFile.getName().length() -4);
for(Enumeration e = zipFile.entries(); e.hasMoreElements();){
ZipEntry ze = (ZipEntry)e.nextElement();
if(ze.getName().contains(".zip")){
is = zipFile.getInputStream(ze);
zis = new ZipInputStream(is);
ZipEntry zentry = zis.getNextEntry();
while (zentry!=null){
System.out.println(zentry.getName());
zentry = zis.getNextEntry();
ZipFile nestFile = new ZipFile(nestPathPrefix+"\\"+zentry.getName());
if (zentry.getName().contains(".zip")) {
processZipFiles(nestPathPrefix+"\\"+zentry.getName());
}
}
is.close();
}
}
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
} finally{
if(is != null)
is.close();
if(zis!=null)
zis.close();
}
}
May be I am doing something wrong - or using the wrong utils. My objective is to identify whether any of the files or nested zip files have got file extensions which I am not allowing. This is to make sure that I can prevent my users to upload forbidden files even when they are zipping it. I also have the option to use Tika which can do recursive parsing (Using Zukka Zitting's solution), but I am not sure if I can use the Metadata to do this detection how I want.
Any help/suggestion is appreciated.

Using Commons Compress would be easier, not least because it has sensible shared interfaces between the various decompressors which make life easier + allows handling of other compression formats (eg Tar) at the same time
If you do want to use only the built-in Zip support, I'd suggest you do something like this:
File file = new File("outermost.zip");
FileInputStream input = new FileInputStream(file);
check(input, file.toString());
public static void check(InputStream compressedInput, String name) {
ZipInputStream input = new ZipInputStream(compressedInput);
ZipEntry entry = null;
while ( (entry = input.getNextEntry()) != null ) {
System.out.println("Found " + entry.getName() + " in " + name);
if (entry.getName().endsWith(".zip")) { // TODO Better checking
check(input, name + "/" + entry.getName());
}
}
}
Your code will fail as you're trying to read inner.zip within outer.zip as a local file, but it doesn't exist as a standalone file. The code above will process things ending with .zip as another zip file, and will recurse
You probably want to use commons compress though, so you can handle things with alternate filenames, other compression formats etc

Converted blob to Mp3 but File is unplayable

This is my function for converting blob to mp3:
private void convertByyeToMP3(byte[] bytearray,String trackName) {
try {
ContextWrapper c = new ContextWrapper(getApplicationContext());
File directory = new File(c.getFilesDir().getAbsolutePath()
+ "/Music");
if (!directory.exists()){
directory.mkdir();
}
File tempMp3 = File.createTempFile(trackName, ".mp3",
directory);
FileOutputStream fos = new FileOutputStream(tempMp3);
fos.write(bytearray);
fos.close();
Log.d("Byte array to mp3 conversion: ", "successfull");
} catch (Exception ex) {
Log.d("In convertToByteToMp3 Function:", ex.toString());
}
}
When I execute this function ,I can see the created mp3 files in my app folder but when I try to play them Using my own code or using ES File Explorer, they both can't play it.
This is the function I use play my music:
private MediaPlayer mp = new MediaPlayer();
private void playSong(String songPath) {
try {
mp.reset();
mp.setDataSource(songPath);
mp.prepare();
mp.start();
} catch (IOException e) {
Log.v(getString(R.string.app_name), e.getMessage());
}
}
And I use this sample code to play the track:
ContextWrapper c = new ContextWrapper(getApplicationContext());
File directory = new File(c.getFilesDir().getAbsolutePath() + "/Music");
playSong(directory.getPath() + File.separator + "kurchina");
This is where I read database and send the blob:
cursor = mDbHelper.GetTables();
byte[] blob = null;
DATAS data = new DATAS();
while (cursor.moveToNext()) {
blob = cursor.getBlob(cursor.getColumnIndex("data"));
if (blob != null) {convertByyeToMP3(blob,data_MusicName);}
db.addDATAS(data);
}
FYIs:
-Read and Write permissions added to manifest.
-Path and filename are check and they exist
-blob byte is not corrupted

There are all sorts of things that might have gone wrong, either in the code that you have shown us or elsewhere. So you need to do your own troubleshooting. Methodically.
Figure out if the problem is with the song file you have extracted or the way you are playing it. For example, try to play the extracted file using a free-standing mp3 player utility.
Assuming that the problem is the extracted file, the next thing is to figure out if the file is the same as the one that you originally inserted into the database. Compare the file sizes and the checksums using the relevant external applications.
and so on.

Found the problem.
It didn't play because the music files were stored in my app folder which is only accessible using a rooted device.
When I copied the music to my sdcard they played well, but in my app folder using rooted nexus 7 I couldn't play it even with an mp3-player app.

java Extracting Zip file

I'm looking for a way to extract Zip file. So far I have tried java.util.zip and org.apache.commons.compress, but both gave a corrupted output.
Basically, the input is a ZIP file contain one single .doc file.
java.util.zip: Output corrupted.
org.apache.commons.compress: Output blank file, but with 2 mb size.
So far only the commercial software like Winrar work perfectly. Is there a java library that make use of this?
This is my method using java.util library:
public void extractZipNative(File fileZip)
{
ZipInputStream zis;
StringBuilder sb;
try {
zis = new ZipInputStream(new FileInputStream(fileZip));
ZipEntry ze = zis.getNextEntry();
byte[] buffer = new byte[(int) ze.getSize()];
FileOutputStream fos = new FileOutputStream(this.tempFolderPath+ze.getName());
int len;
while ((len=zis.read(buffer))>0)
{
fos.write(buffer);
}
fos.flush();
fos.close();
} catch (FileNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} finally
{
if (zis!=null)
{
try { zis.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
}
Many thanks,
Mike

I think your input may be compressed by some "incompatible" zip program like 7zip.
Try investigating first if it can be unpacked with a classical WinZip or such.
Javas zip handling is very well able to deal with zipped archives that come from a "compatible" zip compressor.

It is an error in my code. I need to specify the offset and len of bytes write.

it works for me
ZipFile Vanilla = new ZipFile(new File("Vanilla.zip")); //zipfile defined and needs to be in directory
Enumeration<? extends ZipEntry> entries = Vanilla.entries();// all (files)entries of zip file
while(entries.hasMoreElements()){//runs while there is files in zip
ZipEntry entry = entries.nextElement();//gets name of file in zip
File folderw =new File("tkwgter5834");//creates new directory
InputStream stream = Vanilla.getInputStream(entry);//gets input
FileInputStream inpure= new FileInputStream("Vanilla.zip");//file input stream for zip file to read bytes of file
FileOutputStream outter = new FileOutputStream(new File(folderw +"//"+ entry.toString())); //fileoutput stream creates file inside defined directory(folderw variable) by file's name
outter.write(inpure.readAllBytes());// write into files which were created
outter.close();//closes fileoutput stream
}

Have you tried jUnrar? Perhaps it might work:
https://github.com/edmund-wagner/junrar
If that doesn't work either, I guess your archive is corrupted in some way.

If you know the environment that you're going to be running this code in, I think you're much better off just making a call to the system to unzip it for you. It will be way faster than anything that you implement in java.
I wrote the code to extract a zip file with nested directories and it ran slowly and took a lot of CPU. I wound up replacing it with this:
Runtime.getRuntime().exec(String.format("unzip %s -d %s", archive.getAbsolutePath(), basePath));
That works a lot better.

Extract file from .apk?

in my android app I'm using an own java library that extracts a .db-file from jar. In Java desktop it works well, but when I try to do it on android, the inputstream blocks forever. The copy method looks like this:
InputStream in = classloader.getResourceAsStream(...);
OutputStream out = new FileOutputStream(new File(...));
try {
while ((read = in.read()) != -1) {
out.write(read);
}
} finally {
try {
in.close();
} catch (final Exception e) {
LOGGER.debug("Error", e);
}
try {
out.close();
} catch (final Exception e) {
LOGGER.debug("Error", e);
}
}
I want to copy this file to the external files dir and android.permission.WRITE_EXTERNAL_STORAGE is granted.
Is there a way to access the file in /data/app/...apk? If not, how can I detect that it can not be accessed without blocking forever?

You should put the database-file in the /assets-folder and copy it to the /databases-folder on first run. A tutorial on this can be found here.
However, if you only want to create the tables and some sample-entry's, you might want to use the onCreate()-method from the SQLiteOpenHelper to do so.

Maybe you should store your data in the raw folder, you access it then :)
http://developer.android.com/guide/topics/resources/index.html

Answering to the question : we can only extract the class files from the apk that we have got, we will not get the layout/xml files or any other files.
There are ways by which we can extract the class files from the apk.