How To Change File Permission Using Java

In last tutorial we learn How To Check File Permissions In Java ,Now We learn how to change file permission using java code. now firstly we create a file and check its permission

 

Now we use this java code

 public class ChangeFilePermission {
  
      public static void main(String[] args) {
          String path="D:\\file\\read.txt";
        File file=new File(path);
        if (file.exists()) {
            System.out.println("read="+file.canRead());
            System.out.println("write="+file.canWrite());
            System.out.println("Execute="+file.canExecute());
            file.setReadOnly();
        }      
    }
    
}

Now we again check file permission.Definitely it will as ...

 

How To Check File Permissions In Java

In this program we learn how to know about file permission mode using java code.

 

Now we create a file in read only mode .

public class FilePermission
       public static void main(String[] args) {
           String path="D:\\file\\read.txt";
        File file=new File(path);
        if (file.exists()) {
            System.out.println("read="+file.canRead());
            System.out.println("write="+file.canWrite());
            System.out.println("Execute="+file.canExecute());
        }
       
    }


}

Read All Files From Any Directory(Folder)

Read a given directory(Folder). Filer its file and folder(directory).
and also show name of files and name of folder

import java.io.File;

public class ReadDirectory {
public static void main(String[] args) {
     String path="D:\\a";      
        try {
            File folder= new File(path);
            File[] listOfFiles= folder.listFiles();
        for (int i = 0; i < listOfFiles.length; i++) {
          if (listOfFiles[i].isFile()) {
                  System.out.println("File=" + listOfFiles[i].getName());        
          } else if (listOfFiles[i].isDirectory()) {
        System.out.println("Directory=" + listOfFiles[i].getName());
          }
          }
        } catch (Exception e) {
            System.out.println(e);
        }

}
}

Read One File And Write Other File

In this Program we two file and we copy data of first.txt file in second.txt file using java code

import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;

public class CopyData {

    public static void main(String[] args) throws IOException {
    String pathInput="D:\\a\\first.txt";
    String pathOutput="D:\\a\\second.txt";
    FileInputStream in=null;
    FileOutputStream out=null;
    try {
        in=new FileInputStream(pathInput);
        out=new FileOutputStream(pathOutput);
        int c;
        while ((c=in.read())!=-1) {
            out.write(c);
        }
    } catch (Exception e) {
        System.out.println(e);
    }finally{
        if (!(in==null)) {
            in.close();
        }
        if (!(out==null)) {
            out.close();
        }
       
    }
    System.out.println("Copy Data");
}
   
}

delete file in java

Delete file in java

import java.io.File;

public class DeleteFile {
    public static void main(String[] args) {
          File f=null;
          String path="D:\\a\\hi.txt";
          try {
            f=new File(path);
            boolean b=f.delete();
            System.out.println("file delete="+b);
        } catch (Exception e) {
            System.out.println(e);
        }
    }   
}

Read File LIne By Line In Java

 In this program we read a file line by line using buffered reader

package filles;
import interview_set1.fileRead;

import java.io.BufferedReader;
import java.io.FileInputStream;
import java.io.FileReader;

public class ReadFiles {
public static void main(String[] args) {
    String path="D:\\a\\hi.txt";
    BufferedReader br=null;
    try {
        FileReader fr=new FileReader(path);
        br=new BufferedReader(fr);
        String line;
        while ((line=br.readLine())!=null) {
            System.out.println(line);
        }
       
    } catch (Exception e) {
        System.out.println(e);
    }
}
}

File Create In Java

How To create file in java

Example:

package filles;

import java.io.BufferedWriter;
import java.io.File;
import java.io.FileWriter;

public class CreateFiles {
 
    public static void main(String[] args) {
          try{
             // create new file
             String content = "This is the content to write into create file";
             String path="D:\\a\\hi.txt";
             File file = new File(path);
   
                // if file doesnt exists, then create it
                if (!file.exists()) {
                    file.createNewFile();
                }
   
                FileWriter fw = new FileWriter(file.getAbsoluteFile());
                BufferedWriter bw = new BufferedWriter(fw);
                // write in file
                bw.write(content);
                // close connection
                bw.close();
          }catch(Exception e){
              System.out.println(e);
          }
         
    }
}

File Handling In Java

• How to Create File In java
• How To Read File Line Line In java
• How To Delete File In Java
• How To Write File In java
•  How To Copy Data From One File To Other
• How To Read All File And Folder From Given Directory In Java  
•  How To Check File Permissions In Java
•  How To Change File Permission Using Java

Read File And Count Occurrence Of Word In Java

Read a file and count the occurrence of word in java

import java.io.File;
import java.io.FileReader;
import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.io.IOException;
import java.util.TreeMap;
import java.util.StringTokenizer;

public class fileRead {

    public static void main(String [] args){

        try{
           
            String textFile ="D:\\workspace\\datastructure\\src\\javaprogram\\test.txt";
            BufferedReader input = new BufferedReader(new FileReader(textFile));
           
            //Creating the Map to store the words and their occurrences
            TreeMap<String, Integer> frequencyMap = new TreeMap<String, Integer>();
            String currentLine = null;
           
            //Reading line by line from the text file
            while((currentLine = input.readLine()) != null){
               
                //Parsing the words from each line
                StringTokenizer parser = new StringTokenizer(currentLine, " \t\n\r\f.,;:!?'\"");
                while(parser.hasMoreTokens()){
                    String currentWord = parser.nextToken();
                   
                    Integer frequency = frequencyMap.get(currentWord);
                    if(frequency == null){
                        frequency = 0;                       
                    }
                    //Putting each word and its occurrence into Map
                    frequencyMap.put(currentWord, frequency + 1);
                }
               
            }
           
            //Displaying the Result
            System.out.println(frequencyMap);
                  
        }catch(IOException ie){
            ie.printStackTrace();
            System.err.println("Your entered path is wrong");
        }       
       
    }
   
}