Develop Reference

zip file is being create but without any files in it

i copied this code directly from oracle website. i have two .png file inside d:\barcode. while i run this code myfigs.zip is created in d: drive but it is corruped and 0kb size.
code:-
public class Zip {
static final int BUFFER = 2048;
public static void main (String argv[]) {
try {
BufferedInputStream origin = null;
FileOutputStream dest = new
FileOutputStream("D:\\myfigs.zip");
CheckedOutputStream checksum = new
CheckedOutputStream(dest, new Adler32());
ZipOutputStream out = new
ZipOutputStream(new
BufferedOutputStream(checksum));
//out.setMethod(ZipOutputStream.DEFLATED);
byte data[] = new byte[BUFFER];
// get a list of files from current directory
File f = new File("D:\\barcode");
String files[] = f.list();
for (int i=0; i<files.length; i++) {
System.out.println("Adding: "+files[i]);
FileInputStream fi = new FileInputStream(files[i]);
origin = new BufferedInputStream(fi, BUFFER);
ZipEntry entry = new ZipEntry(files[i]);
out.putNextEntry(entry);
int count;
while((count = origin.read(data, 0,
BUFFER)) != -1) {
out.write(data, 0, count);
}
origin.close();
}
out.close();
System.out.println("checksum: "+checksum.getChecksum().getValue());
} catch(Exception e) {
e.printStackTrace();
}
}
}
to add more information whenever i run the code in debug mode code is successfully compiled to FileInputStream fi line then it is stopped there. the error thrown is
java.io.FileNotFoundException: barcode.png (The system cannot find the file specified)
Adding: barcode.png
at java.io.FileInputStream.open0(Native Method)
at java.io.FileInputStream.open(FileInputStream.java:195)
at java.io.FileInputStream.<init>(FileInputStream.java:138)
at java.io.FileInputStream.<init>(FileInputStream.java:93)

The exception says "file not found". Your "adding" print statement gives you the answer:
Adding: barcode.png
The file "barcode.png" is not the same as the file "D:\barcode\barcode.png". You're just looking for a file named "barcode.png" in whatever your current working directory is set to, and it isn't there.
As per the docs for list() and the conclusion you should have made from your observations of your printed output and exception:
Names denoting the directory itself and the directory's parent directory are not included in the result. Each string is a file name rather than a complete path.
So you need to either:
Change your working directory to "D:\barcode" first, or
Add the parent directory name ("D:\barcode") back to the beginning of your filename ("barcode.png") before opening it, or
Look at some of the other functions File has to offer and see if there's one that helps you avoid this problem entirely.
Couple other minor notes:
It should be no surprise that the zip file was empty, given that your code threw an exception before you wrote anything to it.
"whenever i run the code in debug mode code is successfully compiled to FileInputStream fi line then it is stopped there" - This terminology is not correct. Your error was not a compiler error, it was a runtime error. The code compiled just fine.
The root cause of your problem was blind modification of the code copied from the Oracle site. Note the original comment, "get a list of files from current directory" -- This code assumed the files came from the current working directory. When you added your own directory in, that was no longer the case, and the program broke.

You can use as below code for zip one file:
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.util.zip.ZipEntry;
import java.util.zip.ZipOutputStream;
/**
* Create by Cuder
*
*/
public class SampleZipFile {
/**
* Create by Cuder
*/
public static void main(String[] args) {
ZipOutputStream zipOutputStream = null;
FileInputStream fileInputStream = null;
try {
File fileInput = new File(
"D:\\eclipse4.4\\workspace\\SampleJava\\resource\\sampleZipFile.txt");
File fileOutput = new File(
"D:\\eclipse4.4\\workspace\\SampleJava\\resource\\sampleZipFile.zip");
FileOutputStream fileOutputStream = new FileOutputStream(fileOutput);
zipOutputStream = new ZipOutputStream(fileOutputStream);
fileInputStream = new FileInputStream(fileInput);
ZipEntry entry = new ZipEntry(fileInput.getName());
zipOutputStream.putNextEntry(entry);
byte[] buf = new byte[1024];
int byteRead = 0;
while ((byteRead = fileInputStream.read(buf)) > 0) {
zipOutputStream.write(buf, 0, byteRead);
}
} catch (FileNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} finally {
try {
if (null != fileInputStream) {
fileInputStream.close();
}
if (null != zipOutputStream) {
zipOutputStream.close();
}
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
}

Android java zipping files and send with intent

I have this method that zips files from a List and another method that uses this for send it with mail through intent.
My problem is that when I send it two or three times the app crashes and shows me this.
E/StrictMode: A resource was acquired at attached stack trace but never released. See java.io.Closeable for information on avoiding resource leaks.
java.lang.Throwable: Explicit termination method 'close' not called
at dalvik.system.CloseGuard.open(CloseGuard.java:184)
at java.io.FileOutputStream.<init>(FileOutputStream.java:89)
at java.io.FileOutputStream.<init>(FileOutputStream.java:72)
at com.waffles.vatsandbats.VisaDatai.zip(VisaDatai.java:1172)
at com.waffles.vatsandbats.VisaDatai.sendZippedMail(VisaDatai.java:207)
at com.waffles.vatsandbats.VisaDatai.getFiles(VisaDatai.java:298)
at com.waffles.vatsandbats.VisaDatai$7$1.run(VisaDatai.java:1823)
at android.os.Handler.handleCallback(Handler.java:739)
at android.os.Handler.dispatchMessage(Handler.java:95)
at android.os.Looper.loop(Looper.java:211)
at android.app.ActivityThread.main(ActivityThread.java:5373)
at java.lang.reflect.Method.invoke(Native Method)
at java.lang.reflect.Method.invoke(Method.java:372)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1020)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:815)
The main problem (I think) is in this message
at com.waffles.vatsandbats.VisaDatai.zip(VisaDatai.java:1172)
That refers to this
in = new FileInputStream(files.get(i)
.getCanonicalFile());
Here's the method that creates the zip and that has the error code
public static File zip(List<File> files, String filename) {
File zipfile = new File(filename);
// Create a buffer for reading the files
FileInputStream in=null;
byte[] buf = new byte[1024];
try {
// create the ZIP file
ZipOutputStream out = new ZipOutputStream(new FileOutputStream(
zipfile));
// compress the files
for (int i = 0; i < files.size(); i++) {
in = new FileInputStream(files.get(i)
.getCanonicalFile());
// add ZIP entry to output stream
out.putNextEntry(new ZipEntry(files.get(i).getName()));
// transfer bytes from the file to the ZIP file
int len;
while ((len = in.read(buf)) > 0) {
out.write(buf, 0, len);
}
// complete the entry
out.closeEntry();
in.close();
}
// complete the ZIP file
out.close();
return zipfile;
} catch (IOException ex) {
ex.printStackTrace();
}
return null;
}
The list of files that I zip is several PrintedPdfDocuments with images and texts (this class has it owns disadvantages but Im lazy changing that right now)
I just can't find the problem. Maybe I need to change the method that zips. Any suggestions?

You should close your streams in a finally block to make sure they are closed properly even when an exception occurs.
Also using getCanonicalFile() creates a new file when you are creating your FileInputStream. You probably want:
in = new FileInputStream(files.get(i));

I solved it. I closed the FileInputStream inside the for loop. So every time it looped and opened the stream I also closed it.
I added a own try catch for the close block at finally just for being sure but when I took away the close section in the for loop it crashed.
Here's the working code
public File zip(List<File> files, String filename) {
File zipfile = new File(filename);
FileInputStream in=null;
ZipOutputStream out=null;
// Create a buffer for reading the files
byte[] buf = new byte[1024];
try {
// create the ZIP file
out = new ZipOutputStream(new FileOutputStream(
zipfile));
// compress the files
for (int i = 0; i < files.size(); i++) {
in = new FileInputStream(files.get(i));
// add ZIP entry to output stream
out.putNextEntry(new ZipEntry(files.get(i).getName()));
// transfer bytes from the file to the ZIP file
int len;
while ((len = in.read(buf)) > 0) {
out.write(buf, 0, len);
}
try {
in.close();
} catch (IOException e1) {
e1.printStackTrace();
}
}
} catch (IOException ex) {
ex.printStackTrace();
}finally {
try {
try {
in.close();
} catch (IOException e1) {
e1.printStackTrace();
}
out.closeEntry();
out.close();
}catch (Exception ex) {
ex.printStackTrace();
}
}
return zipfile;
}

Setting permissions for created directory to copy files into it

During the execution of my program it creates a directory which contains two sub-directories/two folders. Into one of these folders I need to copy a Jar-File. My programm resembles an installation routine. The copying of the Jar file is not the problem here, but the permissions of the created directories.
I tried to set the permissions of the directories (before actually creating them with the mkdirs() method) with File.setWritable(true, false) and also with the .setExecutable and .setReadable methods, but the access to the sub-directories is still denied.
Here's an excerpt of my code for the creation of one of the two sub-directories:
folderfile = new File("my/path/to/directory");
folderfile.setExecutable(true, false);
folderfile.setReadable(true, false);
folderfile.setWritable(true, false);
result = folderfile.mkdirs();
if (result) {
System.out.println("Folder created.");
}else {
JOptionPane.showMessageDialog(chooser, "Error");
}
File source = new File("src/config/TheJar.jar");
File destination = folderfile;
copyJar(source, destination);
And my "copyJar" method:
private void copyJar(File source, File dest) throws IOException {
InputStream is = null;
OutputStream os = null;
try {
is = new FileInputStream(source);
os = new FileOutputStream(dest);
byte[] buffer = new byte[1024];
int length;
while ((length = is.read(buffer))>0) {
os.write(buffer, 0, length);
}
} catch (Exception e) {
e.printStackTrace();
}
is.close();
os.close();
}
At os = new FileOutputStream(dest); the debugger throws a FileNotFoundException with the description that the access to the directory has been denied.
Does anyone have an idea what I am doing wrong or have a better solution for setting the permissions via Java? Thanks in advance!

A similar question was asked there are several years.
A possible solution for Java 7 and Unix system is available here : How do i programmatically change file permissions?
Or, below the best response, a example with JNA.
I hope that that will help you !

I solved the problem. In the end it was much easier to solve than expected.
The main problem was not the permission issue but the FileNotFoundException. The file that is assigned to the OutputStream is not really a file, but just a directory so that the Stream can't find it. You have to create the file before initializing the OutputStream and after that you copy your source file into the newly created file. The code:
private void copyJar(File source, File dest) throws IOException {
InputStream is = null;
File dest2 = new File(dest+"/TheJar.jar");
dest2.createNewFile();
OutputStream os = null;
try {
is = new FileInputStream(source);
os = new FileOutputStream(dest2);
byte[] buffer = new byte[1024];
int length;
while ((length = is.read(buffer))>0) {
os.write(buffer, 0, length);
}
} catch (Exception e) {
e.printStackTrace();
}
is.close();
os.close();
}

Java unzip from URL misses 2kb on file

I am trying to unzip a file from the internet using the following code. On one of the files("uq.class"), after it has been unzipped from the online source, is missing about 2kb of file size(the original file is 10,084, unzipped I get 8,261). All the other files seem to be completely fine, and when I copy the uq.class file from the zip and place it in manually, it functions perfectly. Can anyone explain whats going on and provide a fix? Below is the unzipping portions of the code.
public static File unpackArchive(URL url, File targetDir) throws IOException {
if (!targetDir.exists()) {
targetDir.mkdirs();
}
InputStream in = new BufferedInputStream(url.openStream(), 2048);
// make sure we get the actual file
File zip = File.createTempFile("arc", ".zip", targetDir);
OutputStream out = new BufferedOutputStream(new FileOutputStream(zip),2048);
copyInputStream(in, out);
out.close();
return unpackArchive(zip, targetDir);
}
public static File unpackArchive(File theFile, File targetDir) throws IOException {
if (!theFile.exists()) {
throw new IOException(theFile.getAbsolutePath() + " does not exist");
}
if (!buildDirectory(targetDir)) {
throw new IOException("Could not create directory: " + targetDir);
}
ZipFile zipFile = new ZipFile(theFile);
for (Enumeration entries = zipFile.entries(); entries.hasMoreElements();) {
ZipEntry entry = (ZipEntry) entries.nextElement();
File file = new File(targetDir, File.separator + entry.getName());
if (!buildDirectory(file.getParentFile())) {
throw new IOException("Could not create directory: " + file.getParentFile());
}
if (!entry.isDirectory()) {
copyInputStream(zipFile.getInputStream(entry), new BufferedOutputStream(new FileOutputStream(file),2048));
} else {
if (!buildDirectory(file)) {
throw new IOException("Could not create directory: " + file);
}
}
}
zipFile.close();
theFile.delete();
return theFile;
}
public static void copyInputStream(InputStream in, OutputStream out) throws IOException {
byte[] buffer = new byte[1024];
int len = in.read(buffer);
while (len >= 0) {
out.write(buffer, 0, len);
len = in.read(buffer);
}
in.close();
out.close();
}
public static boolean buildDirectory(File file) {
return file.exists() || file.mkdirs();
}

Cannot directly see anything wrong with the code at first sight. What I would recommend you doing however is closing your streams more safely. In your current implementation you close the in and out streams at the same time, close statements can cause exceptions as can read and write statements! If any one of those fails, your files will be left open and in time your application will run out of file descriptors. You're better off doing the closing in a finally statement, that way you're sure they get closed.

I don't know why I cant sign in, but I figured out the issue. I did the whole cart before the horse thing. I extracted the proper file, then extracted the old file over it, so I kept re-integrating the older file. 5 hours of programming out the window. Remember, kiddies, proper programming architecture saves you A TON of headaches.

Problem in Zipping a File

When I run my code and use the files that are in the resource folder of my project itself, I face no problems. It zips the file successfully and I can extract it using WINZIP. The problem comes when I try to zip a file that is not in the project folder.
When I do the same, I am passing the Absolute Path of both the src and the dest files. My program doesn't give any exceptions, but when I try to open that zip file, I get an error saying, File is Invalid.
Can anyone tell me why this may be happening.
public static void compress(String srcPath, String destPath) {
srcFile = new File(srcPath);
destFile = new File(destPath);
try {
fileInputStream = new FileInputStream(srcFile);
fileOutputStream = new FileOutputStream(destFile);
zipEntry = new ZipEntry(srcPath);
zipOutputStream = new ZipOutputStream(fileOutputStream);
zipOutputStream.putNextEntry(zipEntry);
byte[] data = new byte[12];
while ((fileInputStream.read(data)) != -1) {
zipOutputStream.write(data);
}
} catch (Exception e) {
e.printStackTrace();
} finally {
try{
fileInputStream.close();
zipOutputStream.close();}catch (Exception e) {
e.printStackTrace();
}
}
}

You should not store paths with drive letters in your zip file because when you try to extract your zip, it will try to create a directory with the name of the drive and fail.
You will need to change your code so that it removes the drive letter from the path before creating the ZipEntry.