Java File Class

3 Key excerpts on "Java File Class"

• 

  eBook - PDF

  Java Programming

  • Joyce Farrell(Author)
  • 2018(Publication Date)
  • Cengage Learning EMEA

    (Publisher)

  • The Path class is used to create objects that contain information about files and directories, such as their locations, sizes, creation dates, and whether they even exist. • The Files class is used to perform operations on files and directories, such as deleting them, determining their attributes, and creating input and output streams. You can include the following statement in a Java program to use both the Path and Files classes: import java.nio.file.*; The nio in java.nio stands for new input/output because its classes are “new” in that they were not developed until Java 7. Creating a Path To create a Path, you first determine the default file system on the host computer by using a statement such as the following: FileSystem fs = FileSystems.getDefault(); This statement creates a FileSystem object using the getDefault() method in the FileSystems class. The statement uses two different classes. The FileSystem class, without an ending s, is used to instantiate the object. FileSystems, with an ending s, is a class that contains factory methods, which assist in object creation. The false statement is #1. Internal computer memory (RAM) is volatile storage; disk storage is nonvolatile. TWO TRUTHS & A LIE Understanding Computer Files 1. An advantage of modern computer systems is that both internal computer memory and disk storage are nonvolatile. 2. Data files contain facts and figures; program files store software instructions that might use data files. 3. A complete list of the disk drive plus the hierarchy of directories in which a file resides is the file’s path. Copyright 2019 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part. Due to electronic rights, some third party content may be suppressed from the eBook and/or eChapter(s). Editorial review has deemed that any suppressed content does not materially affect the overall learning experience.

  Sign up to read

  Learn more about book
• 

  eBook - ePub

  100+ Solutions in Java - 2nd Edition

  Everything you need to know to develop Java applications (English Edition)

  • Dhruti Shah(Author)
  • 2023(Publication Date)
  • BPB Publications

    (Publisher)

  getParent() method helps to resolve the parent of an abstract pathname.

  A File class instance is immutable, hence, the abstract pathname represented by a File object cannot be changed once it is created. The File class stores the name and path of a file or directory and allows file manipulation through various access methods. The common operations supported include create, delete, rename, list files, and so on. File permissions need to be determined before performing any operation.

  Listed below are some important constructors of the java.io.File class:

  • File(String path) : Creates a File object with the specified pathname.
  • File(String parent, String child) : Creates a File object with the specified parent and child parameters for the pathname. Here, the parent points to the directory, and the child refers to a directory or a file.
  • File(File obj, String filename) : Creates a File object from another File object and file or directory name.
  • File(URL obj) : Converts the given URL into a pathname and generates a new File object.

  Listed below are some methods of the File class:

  • boolean exists() : Checks if the given file or directory exists.
  • boolean isFile() : Checks if the object is a normal file.
  • String getPath() : Returns the abstract pathname as a string.
  • boolean mkdir() : Creates a new directory by the given abstract pathname.
  • boolean createNewFile() : Creates a new empty file with the given file name, only if a file with a similar name does not exist. The method throws IOException

  Sign up to read

  Learn more about book
• 

  eBook - PDF

  C# For Java Programmers

  • Harold Cabrera(Author)
  • 2002(Publication Date)
  • Syngress

    (Publisher)

  Working with I/O Streams Solutions in this chapter: 406 Chapter 11 • Working with I/O Streams Introduction One of Java’s great features is providing a layer of abstraction for performing input/output and networking operations.The Java model for IO uses streams, something familiar to most Java programmers. C# also uses streams and provides a rich set of libraries for hiding the complications of data transfer.The counterpart of the java.io package is the System.IO namespace. Classes in the System.IO namespace allow you to read and write information to a file, or to the console. Other pack-ages, such as System.Net.Socket, support streams for network connections. File System In Java, files and directories are handled using a single class called File .This ambiguous design sometimes leads to confusion since it can be difficult to deter-mine if a file or directory is being used. C# distinguishes between files and direc-tories by giving us two classes to handle disk operations: File and Directory .These two classes use only static methods to perform disk operations, but there are also two corresponding classes that perform disk operations on instances: FileInfo and DirectoryInfo . For Java programmers, the latter seems more familiar. C# uses a base class for FileInfo and DirectoryInfo called FileSystemInfo .This base class contains only methods that are common to both directories and files. Many of the methods in FileSystemInfo have counterparts in java.io.File . C# also has methods that have no counterpart in Java, since the Java strategy is to create only methods that are universal across different platforms. For example, methods for accessing the last time a file was accessed or when a file was created are unique to C#. Directories The two classes for handling directories are Directory and DirectoryInfo .

  Sign up to read

  Learn more about book