File class properties, constructors and methods

Class File 

Lets discuss few properties of class File, constructors and the methods of file class.

java.lang.Object
  java.io.File

All Implemented Interfaces:
Serializable, Comparable<File>

public class File
extends Object
implements Serializable, Comparable<File>



Constructors:
1. File f=new File(String name);
2. File f=new File(String subdir, String name);
3. File f=new File(File f1, String name);



Methods of Class File
Below are all the methods present in Class File. The once highlighted in Yellow  are the most often used.



Method Summary
 boolean
canExecute() 
          Tests whether the application can execute the file denoted by this abstract pathname.
 boolean
canRead() 
          Tests whether the application can read the file denoted by this abstract pathname.
 boolean
canWrite() 
          Tests whether the application can modify the file denoted by this abstract pathname.
 int
compareTo(File pathname) 
          Compares two abstract pathnames lexicographically.
 boolean
createNewFile() 
          Atomically creates a new, empty file named by this abstract pathname if and only if a file with this name does not yet exist.
static File
createTempFile(String prefix, String suffix) 
          Creates an empty file in the default temporary-file directory, using the given prefix and suffix to generate its name.
static File
createTempFile(String prefix, String suffix, File directory) 
           Creates a new empty file in the specified directory, using the given prefix and suffix strings to generate its name.
 boolean
delete() 
          Deletes the file or directory denoted by this abstract pathname.
 void
deleteOnExit() 
          Requests that the file or directory denoted by this abstract pathname be deleted when the virtual machine terminates.
 boolean
equals(Object obj) 
          Tests this abstract pathname for equality with the given object.
 boolean
exists() 
          Tests whether the file or directory denoted by this abstract pathname exists.
 File
getAbsoluteFile() 
          Returns the absolute form of this abstract pathname.
 String
getAbsolutePath() 
          Returns the absolute pathname string of this abstract pathname.
 File
getCanonicalFile() 
          Returns the canonical form of this abstract pathname.
 String
getCanonicalPath() 
          Returns the canonical pathname string of this abstract pathname.
 long
getFreeSpace() 
          Returns the number of unallocated bytes in the partition named by this abstract path name.
 String
getName() 
          Returns the name of the file or directory denoted by this abstract pathname.
 String
getParent() 
          Returns the pathname string of this abstract pathname's parent, or null if this pathname does not name a parent directory.
 File
getParentFile() 
          Returns the abstract pathname of this abstract pathname's parent, or null if this pathname does not name a parent directory.
 String
getPath() 
          Converts this abstract pathname into a pathname string.
 long
getTotalSpace() 
          Returns the size of the partition named by this abstract pathname.
 long
getUsableSpace() 
          Returns the number of bytes available to this virtual machine on the partition named by this abstract pathname.
 int
hashCode() 
          Computes a hash code for this abstract pathname.
 boolean
isAbsolute() 
          Tests whether this abstract pathname is absolute.
 boolean
isDirectory() 
          Tests whether the file denoted by this abstract pathname is a directory.
 boolean
isFile() 
          Tests whether the file denoted by this abstract pathname is a normal file.
 boolean
isHidden() 
          Tests whether the file named by this abstract pathname is a hidden file.
 long
lastModified() 
          Returns the time that the file denoted by this abstract pathname was last modified.
 long
length() 
          Returns the length of the file denoted by this abstract pathname.
 String[]
list() 
          Returns an array of strings naming the files and directories in the directory denoted by this abstract pathname.
 String[]
list(FilenameFilter filter) 
          Returns an array of strings naming the files and directories in the directory denoted by this abstract pathname that satisfy the specified filter.
 File[]
listFiles() 
          Returns an array of abstract pathnames denoting the files in the directory denoted by this abstract pathname.
 File[]
listFiles(FileFilter filter) 
          Returns an array of abstract pathnames denoting the files and directories in the directory denoted by this abstract pathname that satisfy the specified filter.
 File[]
listFiles(FilenameFilter filter) 
          Returns an array of abstract pathnames denoting the files and directories in the directory denoted by this abstract pathname that satisfy the specified filter.
static File[]
listRoots() 
          List the available filesystem roots.
 boolean
mkdir() 
          Creates the directory named by this abstract pathname.
 boolean
mkdirs() 
          Creates the directory named by this abstract pathname, including any necessary but nonexistent parent directories.
 boolean
renameTo(File dest) 
          Renames the file denoted by this abstract pathname.
 boolean
setExecutable(boolean executable) 
          A convenience method to set the owner's execute permission for this abstract pathname.
 boolean
setExecutable(boolean executable, boolean ownerOnly) 
          Sets the owner's or everybody's execute permission for this abstract pathname.
 boolean
setLastModified(long time) 
          Sets the last-modified time of the file or directory named by this abstract pathname.
 boolean
setReadable(boolean readable) 
          A convenience method to set the owner's read permission for this abstract pathname.
 boolean
setReadable(boolean readable, boolean ownerOnly) 
          Sets the owner's or everybody's read permission for this abstract pathname.
 boolean
setReadOnly() 
          Marks the file or directory named by this abstract pathname so that only read operations are allowed.
 boolean
setWritable(boolean writable) 
          A convenience method to set the owner's write permission for this abstract pathname.
 boolean
setWritable(boolean writable, boolean ownerOnly) 
          Sets the owner's or everybody's write permission for this abstract pathname.
 String
toString() 
          Returns the pathname string of this abstract pathname.
 URI
toURI() 
          Constructs a file: URI that represents this abstract pathname.
 URL
toURL() 
          Deprecated. This method does not automatically escape characters that are illegal in URLs. It is recommended that new code convert an abstract pathname into a URL by first converting it into a URI, via the toURI method, and then converting the URI into a URL via the URI.toURL method.