Programming Articles - Page 2856 of 3363

In this article, we will learn to use Java to make a file read-only and check if it can still be written. A file can be set to read-only by using the method java.io.File.setReadOnly(). This method requires no parameters and returns true if the file is set to read-only and false otherwise. The method java.io.File.canWrite() is used to check whether the file can be written in Java and if not, then the file is confirmed to be read-only. Problem StatementThe task is to write a Java program that makes the file read-only and then checks whether the file can still ... Read More

A file or directory with the required abstract pathname can be deleted when the program ends i.e. after the virtual machine terminates using the method java.io.File.deleteOnExit(). This method requires no parameters and it does not return a value.A program that demonstrates this is given as follows −Example Live Demoimport java.io.File; public class Demo {    public static void main(String[] args) {       try {          File file = new File("demo1.txt");          file.createNewFile();          System.out.println("File: " + file);          file.deleteOnExit();       } catch(Exception e) {   ... Read More

The java.io.File class has display constants File.separatorChar and File.pathSeparatorChar mainly. The File.separatorChar is ‘/’ and the File.pathSeparatorChar is ‘:’ for Unix.A program that demonstrates this is given as follows −Example Live Demoimport java.io.File; public class Demo {    public static void main(String[] args) {       try {          System.out.println("File.pathSeparatorChar = " + File.pathSeparatorChar);          System.out.println("File.separatorChar = " + File.separatorChar);       } catch(Exception e) {          e.printStackTrace();       }    } }The output of the above program is as follows −OutputFile.pathSeparatorChar = : File.separatorChar = /Now let ... Read More

A new empty file with the required abstract path name can be created using the method java.io.File.createNewFile(). This method requires no parameters and it returns true if the file is newly created and it did not exist previously. If the file existed previously, it returns false.A program that demonstrates this is given as follows −Example Live Demoimport java.io.File; public class Demo {    public static void main(String[] args) {       try {          File file = new File("demo1.txt");          file.createNewFile();          System.out.println("File: " + file);       } catch(Exception ... Read More

A directory can be created with the required abstract path name using the method java.io.File.mkdir(). This method requires no parameters and it returns true on the success of the directory creation or false otherwise.A program that demonstrates this is given as follows −Example Live Demoimport java.io.File; public class Demo {    public static void main(String[] args) {       try {          File file = new File("c:\demo1\");          file.createNewFile();          boolean flag = file.mkdir();          System.out.print("Directory created? " + flag);       } catch(Exception e) {   ... Read More

The method File.renameTo() method of the java.io package is used to rename a file or directory. This method requires a single parameter i.e. the name that the file or directory is renamed to and it returns true on the success of the renaming or false otherwise. Syntax public boolean renameTo(File dest) Steps to rename a file or directory using File renameTo() method Below are the steps to rename a file or directory using the File renameTo() method − Import File class from java.io package Define the demo class with the main method. ... Read More

The length of the current file specified by the abstract path name can be displayed using the method java.io.File.length(). The method returns the file length in bytes and does not require any parameters.A program that demonstrates this is given as follows −Example Live Demoimport java.io.File; public class Demo {    public static void main(String[] args) {       try {          File file = new File("demo1.txt");          file.createNewFile();          System.out.println("Length of file: " + file.length());       } catch(Exception e) {          e.printStackTrace();       } ... Read More

The method java.io.File.getAbsoluteFile() is used to get the File object with the absolute path for the directory or file. This method requires no parameters.A program that demonstrates this is given as follows −Example Live Demoimport java.io.File; public class Demo {    public static void main(String[] args) {       File file = new File("C:" + File.separator + "jdk11.0.2" + File.separator, "demo1.java");       System.out.println("The absolute file is: " + file.getAbsoluteFile());    } }The output of the above program is as follows −OutputThe absolute file is:/C:/jdk11.0.2/demo1.javaNow let us understand the above program.The file object with the absolute path is obtained ... Read More

The method java.io.File.getAbsolutePath() is used to obtain the absolute path name of a file or directory in the form of a string. This method requires no parameters.A program that demonstrates this is given as follows −Example Live Demoimport java.io.File; public class Demo {    public static void main(String[] args) {       File file = new File("C:" + File.separator + "jdk11.0.2" + File.separator, "demo1.java");       System.out.println("The absolute path name is: " + file.getAbsolutePath());    } }The output of the above program is as follows −OutputThe absolute path name is:/C:/jdk11.0.2/demo1.javaNow let us understand the above program.The absolute pathname of ... Read More

The method java.io.File.canWrite() is used to check whether the file can be written to in Java. This method returns true if the file specified by the abstract path name can be written to by an application and false otherwise.A program that demonstrates this is given as follows −Example Live Demoimport java.io.File; public class Demo {    public static void main(String[] args) {       try {          File file = new File("demo1.txt");          file.createNewFile();          System.out.println("The file can be written to? " + file.canWrite());       } catch(Exception e) { ... Read More