File Handling in JAVA

We can handle normal text file in java. For that, we must import java.io package. and create an object of the File class. This object can determine if a file exists or not. If exists, then we can easily do any thing with that file in the following example we find and count the occurrence of a pattern in a file. For that, we must create a file called test.txt in any directory [Here we put in in the same directory of the java file] and put some text in it.

Write a program that takes a file name and a search string from the user. If the search string occurs in the file, then it counts the number of occurrences of the string. ( Assume that search pattern can exist more than two times in a line ). [WBUT MCA JAVA 2011]

import java.util.*;
import java.io.*;
public class FileSearch
{
public static void main(String []args)
{
Scanner sc=new Scanner(System.in);
System.out.print("Enter a File Name : ");
String fname=sc.nextLine();
System.out.print("Enter a Word : ");
String word=sc.nextLine();
int count=0;
try
{
File f=new File(fname);
if(f.exists())
{
BufferedReader br = new BufferedReader(new FileReader(f));
String line;
String []words;
int i;
while ((line = br.readLine()) != null)
{
words=line.split(" ");
for(i=0;i<words.length;i++)
{
if(words[i].equals(word))
{
count++;
}
}
}
System.out.print("Frequency of the word \"" + word + "\" in the file " + fname + " are " + count);
}
else
{
System.out.print("File Not Found");
}
}
catch(Exception e)
{
System.out.print(e.toString());
}
}
}

Output:

Enter a File Name : test.txt
Enter a Word : You
Frequency of the word "You" in the file test.txt are 3