Why java.io.File doesn't have a close() method?
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java.io.RandomAccessFile does have a
java.io.File doesn't. Why is that? Is the file closed automatically on finalization or something?
The javadoc of the
File class describes the class as:
An abstract representation of file and directory pathnames.
File is only a representation of a pathname, with a few methods concerning the filesystem (like
exists()) and directory handling but actual streaming input and output is done elsewhere. Streams can be opened and closed, files cannot.
(My personal opinion is that it's rather unfortunate that Sun then went on to create
RandomAccessFile, causing much confusion with its inconsistent naming.)
Java.io.File Class in Java, Instances may or may not denote an actual file-system object such as a file or a directory. If it does denote such an object then that object resides in a partition. A The java.nio.file package defines interfaces and classes for the Java virtual machine to access files, file attributes, and file systems. This API may be used to overcome many of the limitations of the java.io.File class.
java.io.File doesn't represent an open file, it represents a path in the filesystem. Therefore having
close method on it doesn't make sense.
Actually, this class was misnamed by the library authors, it should be called something like
Java.io.File Class, The javadoc of the File class describes the class as: An abstract representation of file and directory pathnames. File is only a representation of a java.io.File doesn't represent an open file, it represents a path in the filesystem. Therefore having close method on it doesn't make sense. Actually, this class was misnamed by the library authors, it should be called something like Path.
Essentially random access file wraps input and output streams in order to manage the random access. You don't open and close a file, you open and close streams to a file.
Why java.io.File doesn't have a close() method?, The Java File class of the Java IO API enables you to do basic file Check if File or Directory Exists; Create a Directory if it Does Not Exist; File [Android.Runtime.Register("java/io/File", ApiSince=1, DoNotGenerateAcw=true)] public class File : Java.Lang.Object, IDisposable, Java.IO.ISerializable, Java.Lang.IComparable type File = class inherit Object interface ISerializable interface IJavaObject interface IDisposable interface IComparable
A BufferedReader can be opened and closed but a File is never opened, it just represents a path in the filesystem.
Java File, Files and directories are both represented by File objects. When a File object is created, the system doesn't test to see if a corresponding file/directory actually The user that owns the AEM java process doesn't have proper permissions to write in the java process' temp directory. Resolution Find out if the JVM parameter -Djava.io.tmpdir is set on the java process
Say suppose, you have
File f = new File("SomeFile"); f.length();
You need not close the
Files, because its just the representation of a path.
You should always consider to close only reader/writers and in fact streams.
Java: java.io.File, In Java create file tutorial, we show how to create a file in Java. We also use two third-party libraries: Apache Commons IO and Google Guava. The createNewFile() returns true if the named file does not exist and was When a java.io.File object is in use either via FileInputStream constructor (for reading the file) or ZipFile (for reading Zip file), delete method should be returning false (boolean) since the File itself is currently in use. But on UNIX JVM, it ignores that the File is in use & simply removes it from the underlying filesystem.
Java create file tutorial - learn how to create a file in Java, Class java.io.File. java.lang.Object | +----java.io.File Returns: the time the file specified by this object was last modified, or 0L if the specified file does not exist. I'm trying to delete a file using File.delete(), but it keeps returning false. I've verified that path to the file is correct and that the permissions on the file allow deleting, but it still doesn't work.
Class java.io.File, File Class. The java.io.File class encapsulates access to information about a it doesn't provide the API for reading and writing file data; there are file streams Verify that Java is enabled in the Java Control panel. If Java is not enabled in the Java Control Panel, you will be unable to run Java applications in any browser. » Enable Java content in the browser using the Java Control panel. Configure security settings. Ensure that the Java security level is not preventing the application from running.
File I/O - Learning Java, 4th Edition [Book], [Android.Runtime.Register("java/io/File", ApiSince=1, DoNotGenerateAcw=true)] public class File : Java.Lang.Object, IDisposable, Java.IO.ISerializable, Java. The File.createNewFile() method creates a new, empty file named by this abstract pathname if and only if a file with this name does not yet exist. This methods return a true value if the file is created successfully and false if the file already exists or the operation failed.
- If you look into Java API, you will be able to get the answer immediately.
- I've learned that people are more helpful than the otherwise superb Java spec.
- b/c it cannot be opened :)
- Because it doesn't open anything. And people are considerably less reliable than the offical Java specification.
- But then what about all the directory listing methods? They should've been separated from the
- Agreed, but in any case, either File or RandomAccessFile is wrongly named. Something like RandomAccessFileStream could be better, but it's many year too late now.
- "Actually, this class was misnamed by the library authors, it should be called something like Path" --> They heard you. In the nio (New I/O) package, the similar classe is now named Path. docs.oracle.com/javase/7/docs/api/java/nio/file/Path.html
- Yes. I never looked much into java.io.RandomAccessFile. I always assumed it overrode java.io.File but it does not!. File represents a path. RandomAccessFile is an object that can perform disk I/O as streams can, albeit with a much different implementation, to allow random rather than streamed access.