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Java FilePermission implies() Method with Example

FilePermission Class implies() method: Here, we are going to learn about the implies() method of FilePermission Class with its syntax and example.
Submitted by Preeti Jain, on April 02, 2020

FilePermission Class implies() method

• implies() method is available in java.io package.
• implies() method is used to check whether this FilePermission implies the given permission (perm) or not.
• implies() method is a non-static method, it is accessible with the class object only and if we try to access the method with the class name then we will get an error.
• implies() method does not throw an exception at the time of implies the given permission.

Syntax:

    public boolean implies(Permission perm);

Parameter(s):

• Permission perm – represents the permission object to be checked.

Return value:

The return type of the method is boolean, it returns true based on some statements:

• When the given permission object is an instance of FilePermission.
• When the given permission actions are a proper subset of this FilePermission object actions.
• When the pathname of the given permission object is implied by this FilePermission object pathname.
• Otherwise, it returns false.

Example:

// Java program to demonstrate the example 
// of boolean implies(Permission perm) method 
// of FilePermission

import java.io.*;

public class ImpliesOfFP {
 public static void main(String[] args) throws Exception {
  FilePermission fp1 = null;
  FilePermission fp2 = null;

  try {
   // Instantiates FilePermission fp1 , fp2 
   fp1 = new FilePermission("D:\\includehelp.txt", "read");
   fp2 = new FilePermission("D:\\includehelp.txt", "write");

   // By using implies() method is to check
   // whether this FilePermission implies the
   // given permission or not
   boolean status = fp1.implies(fp1);
   System.out.println("fp1.implies(fp1): " + status);

   status = fp2.implies(fp1);
   System.out.println("fp2.implies(fp1): " + status);
  } catch (Exception ex) {
   System.out.println(ex.toString());
  }
 }
}

Output

fp1.implies(fp1): true
fp2.implies(fp1): false