Getting a absolute path

To find a file or directory it is very necessary to know the path of the file or directory so that you can access it. If you know the path then it is very easy to work on it. Suppose a situation where a problem comes in front you where you don't know the path of the file, then what will you do. Then this problem can be solved by using a method getAbsolutePath().The method getAbsolutePath() should be used where we don't know the exact path of the file.
To find an absolute path of a file, Firstly we have to make a class GetAbsolutePath. Inside this class define the main method. Inside this method  define a File class of java.io package. Inside the constructor of a File class pass the name of the file whose absolute path you want to know. Now call the method getAbsolutePath() of the File class by the reference of  File class and store it in a String variable. Now print the string, you will get a absolute path of the file.
In this class we have make use of the following things by which this problem can be solved.
File: It is class in java.io package. It implements Comparable and Serializable interface.
getAbsolutePath():  It returns the absolute path name in  the form of string.
Code of the program is given below:

import java.io.*;

  public class  GetAbsolutePath{
 
 public static void main(String[] args){
 
   String str = args[0];


      File file = new File(str);
    String absolutePathOfFirstFile = file.getAbsolutePath();

    System.out.println(" The absolute path in first form is " 
                          + absolutePathOfFirstFile);


      file = new File( "chandan" + File.separatorChar+ str);
    String absolutePathOfSecondFile = file.getAbsolutePath();
    System.out.println(" The absolute path is " + absolutePathOfSecondFile);


      file = new File("chandan" + File.separator + ".." + File.separator + str);
    String absolutePathOfThirdFile = file.getAbsolutePath();
    System.out.println(" The absolute path is " + absolutePathOfThirdFile); 

    }
 
} 

Output of the program 

C:\java>java GetAbsolutePath chandan The absolute path in first form is C:\tapan\chandan The absolute path is C:\tapan\chandan\chandan The absolute path is C:\tapan\chandan\..\chandan

Download this example.
Getting the Parents of a Filename
Program uses getParent( ) method of the File class object to find the parent directory name of the current directory. For example,
System.getProperty("user.dir"):
This method returns the user's current directory. The getProperty() method is the system method which is imported from the System class of the java.lang.*; package. This method tells about the system property according to the indicating argument. Here, the indicating argument user.dir indicates about the current directory.
Here is the code of the program : 

import java.io.*;

  public class  GetParentDir{
 
 private static void dirlist(String fname){

    File dir = new File(fname);

    String parentpath = dir.getParent();
  
  System.out.println("Current Directory : "+ dir);

    System.out.println("parent Directory : "+ parentpath);
 
 }

 
  public static void main(String[] args){
 
   String currentdir = System.getProperty("user.dir");

    dirlist(currentdir);
 
 }

} 

Output of the program 

C:\nisha>javac GetParentDir.java C:\nisha>java GetParentDir Current Directory : C:\nisha parent Directory : C:\ C:\nisha>

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