java-io

I'm trying to stitch some images together using java. I have a bunch of images I'd like to stitch together and they are all the same dimensions so it's really just a question of lining them up next to each other I suppose. I have it working but it's very slow and probably very memory intensive. I'm wondering if there's an easier way: public static void main(String[] args) throws IOException { int dim = 256; BufferedImage merged = null; for(int y = 0; y<10;y++) { for(int x = 0; x<10;x++) { URL url = new URL(someURL); BufferedImage nextImage = ImageIO.read(url); if(merged==null) merged=nextImage

I have some code that saves some preferences to file using FileOutputStream . It is standard code I've written a thousand times: FileOutputStream out = new FileOutputStream(file); try { BufferedOutputStream bos = new BufferedOutputStream(out); try { store(bos, comments); } finally { bos.close(); } } finally { out.close(); } One of our users is reporting the following error on Linux during the close() call. java.io.IOException: Inappropriate ioctl for device at java.io.FileOutputStream.close0(Native Method) at java.io.FileOutputStream.close(FileOutputStream.java:341) at java.io

Assumption: Stream s are lazy, hence the following statement does not load the entire children of the directory referenced by the path into memory; instead it loads them one by one, and after each invocation of forEach , the directory referenced by p is eligible for garbage collection, so its file descriptor should also become closed: Files.list(path).forEach(p -> absoluteFileNameQueue.add( p.toAbsolutePath().toString() ) ); Based on this assumption, I have implemented a breadth-first file traversal tool: public class FileSystemTraverser { public void traverse(String path) throws IOException {

In the book I'm reading on Java, it demonstrates serialization by using a program that writes to a file and stores it away. I'm getting a strange error that I don't know how to read and it denies me access to creating a .txt file. Here's the error: Exception in thread "main" java.io.FileNotFoundException: C:\testFile.txt (Access is denied) at java.io.FileOutputStream.open(Native Method) at java.io.FileOutputStream.<init>(Unknown Source) at java.io.FileOutputStream.<init>(Unknown Source) at serializableTests.MyProgram.main(MyProgram.java:18) Here's the two classes for the program: User class:

The Java.iO.File document says the following words about its constructor which takes the pathname : public File(String pathname) Creates a new File instance by converting the given pathname string into an abstract pathname. If the given string is the empty string, then the result is the empty abstract pathname. But what if the pathname points to a file which is already existing ? File file = new File(PATH_TO_AN_EXISTING_FILE); Does the above file instance represent a fresh new file (with the existing one be deleted?) Or does it represent the existing file ? What the documentation says is that

i am writing a code i am creating a directory with java nio api my segment of code is Path target = Paths.get(""+folder_path+xx[0]); Set<PosixFilePermission> perms = null; if(xx[2].toLowerCase().equals("read")) perms =PosixFilePermissions.fromString("r--------"); if(xx[2].toLowerCase().equals("read/write")) { perms =PosixFilePermissions.fromString("rw-------"); } FileAttribute<Set<PosixFilePermission>> attr = PosixFilePermissions.asFileAttribute(perms); Files.createDirectory(target, attr); but it is throwing an error java.nio.file.FileAlreadyExistsException: /home/ritesh/Desktop/userA reason i

I am writing a JUnit for a program created in an exercise. That means the test needs to cover as many cases as possible and I don't have any influence on how certain things in the program are implemented. Also, the program runs an infinite loop where at one point, it requires the user to input something. For the JUnit test I run the program in another Thread and simulate the user input from within the JUnit Thread . So far, everything works fine if the program reads the user input from System.in , because this stream can easily replaced. But there's also the possiblity that the program