How to read and write a file in java?

This article will show how we can read and write files from user input.

Java program to read a file line by line and display output:

Algorithm: Java program to read file

1. import java.io.*; package
2. create class Filedemo{
3. Create function: public static void p(String str){
   1. Print String: System.out.println(str);
4. Againg create another function: public static void analyze(String s){
   1. File f = new File(s)’
5. if( f.exists()){
   1. p(f.getName()+” is a file”);

   2.  p(f.canRead()?” is readable”:” is not readable”);

   3. p(f.canWrite()?” is writable”:” is not writable”);

   4. p(“Filesize:”+f.length()+” bytes”);

   5. p(“File last mdified:”+f.lastModified());

6.    if(f.isDirectory()) then

   1. p(f.getName()+” is directory”);

   2. p(“List of files”);

   3. String dir[]=f.list();

   4.  for(int i=0;i<dir.length;i++)

   5. p(dir[i])
7. Create main function: public static void main(String rr[])throws IOException{
   1. filedemo fd=new filedemo();
   2. BufferedReader br=new BufferedReader(new InputStreamReader(System.in));
   3. System.out.println(“Enter the file name:”);
   4. String s=br.readLine();
   5. fd.analyze(s);

Source Code: File Readable | File Writeable | Types of file | Size of file

import java.io.*;
class filedemo
{
public static void p(String str)
{
    System.out.println(str);
 }
 public static void analyze(String s)
File f=new File(s);
 if(f.exists())
 {
 p(f.getName()+" is a file");
 p(f.canRead()?" is readable":" is not readable");
 p(f.canWrite()?" is writable":" is not writable");
 p("Filesize:"+f.length()+" bytes");
 p("File last mdified:"+f.lastModified());
 }
 if(f.isDirectory())
 {
 p(f.getName()+" is directory");
 p("List of files");
 String dir[]=f.list();
 for(int i=0;i<dir.length;i++)
 p(dir[i]);
 }
 }

}
public class FileDetails
{
 public static void main(String rr[])throws IOException
 {
 filedemo fd=new filedemo();
 BufferedReader br=new BufferedReader(new InputStreamReader(System.in));
 System.out.println("Enter the file name:");
 String s=br.readLine();
 fd.analyze(s);
 }
}

Expected Output: