The Java.io File is started to use in java 1.0 onwards but coming to 1.2, 1.3 slowly stopped using Java.io File classes and used databases like oracle mysql to store and access data. But from java1.5 onwards Java.io File is also using because of storing huge data we are going for database then to store bits of data use file i/o.

 File f = newfile (“a.text”); Because of the above syntax, no physical file is created. Only the java file object with name a.text is created. The function of  this object is to check whether the file is already existing or not. If file is available then f pointing to that file else creating an new file by using below syntax. The java file object represents both directory and file.

F.create newfile();

Java.io.File class is declared as shown below: Public class File extends Object implements serializable

The fields for Java.io File class are as follows:

• Static String separator: The String separator field depends on system and represents with name string by default.
• Static String pathSeparator: The String pathSeparator field depends on system and represents the pathSeparator as string.
• Static char separatorChar: The Char SeparatorChar field depends on system and represents with name Char by default.
• Static char pathSeparatorChar: The Char pathSeparatorChar field depends on system and represents with name Char.

From the following class, methods are inherited to Java.io.File :

• Java.io.Object

Usage of  boolean canExecute() method. [c]import java.io.File; public class FileDemo { public static void main(String[] args) { File fl = null; String[] str = { "test.txt", "/test.txt" }; try { // Representing each string in string array for (String s : str) { // Creating new file fl = new File(s); // file is executable then it returns true boolean bool = fl.canExecute(); // To find the absolute path String a = fl.getAbsolutePath(); // To prints absolute path System.out.print(a); // print System.out.println(" is executable: " + bool); } } catch (Exception e) { // if any issues I/O error occurs e.printStackTrace(); } } }[/c] OutPut The result is as follows. [c]D:\Spring\Test\test.txt is executable: false D:\test.txt is executable: false[/c] Usage of Boolean canRead() method. [c] import java.io.File; public class Splesson { public static void main(String[] args) { File f = null; try { // creating a new file f = new File("c:/test.txt"); // if the file can be read it returns true boolean bl = f.canRead(); // print System.out.print("File can be read: " + bl); } catch (Exception e) { // if any issues I/O error occurs e.printStackTrace(); } } }[/c] OutPut The result is as follows. [c] File can be read: false[/c] Usage of Boolean mkdir() method. [c]import java.io.File; public class FileMkdir { //public class FileDemo { public static void main(String[] args) { File f = null; boolean bl = false; try{ //For files and directory it returns pathnames f = new File("C:/Text"); // create a directory bl = f.mkdir(); // print the output System.out.print("Directory created? "+bl); }catch(Exception e) { // if any other error occurs e.printStackTrace(); } } }[/c] OutPut The result is as follows. [c]Directory created? true [/c] Usage of File.Length() method. [c]import java.io.File; public class FileLength { //public class FileDemo { public static void main(String[] args) { File f = null; String path; long n; boolean bl = false; try{ // creating new file f = new File("c:/abc.txt"); // Returns true if the file path is a file, else false bl = f.exists(); // If the path exists if(bl) { // It returns the length in bytes n = f.length(); // Represents path path = f.getPath(); // printing the length of file System.out.print(path+" file length: "+n); } }catch(Exception e){ // if any other error occurs e.printStackTrace(); } } } [/c] OutPut The result is as follows. [c]c:\abc.txt file length: 5 [/c] Usage of File.isHidden() method. [c]import java.io.File; public class FileHidden { public static void main(String[] args) { File f = null; String path; boolean bl = false; try{ // creating new file f = new File("c:/abc.txt"); // Returns true if the file path is a hidden file bl = f.isHidden(); // get the file path path = f.getPath(); // prints is file hidden or not System.out.print(path+" is file hidden? "+bl); }catch(Exception e) { // if any error occurs e.printStackTrace(); } } }[/c] OutPut The result is as follows. [c]c:\abc.txt is file hidden? false[/c]

• Java.io File - The Java.io File is started to use in java 1.0 onwards.
• Java.io File - But from java1.5 onwards Java.io File is also using because of storing huge data we are going for database then to store bits of data use file i/o.