Не считает
package com.javarush.task.task19.task1907;
import java.io.BufferedReader;
import java.io.FileReader;
import java.io.IOException;
import java.io.InputStreamReader;
// Считаем слово world в файле
public class Solution {
public static void main(String[] args) throws IOException {
BufferedReader buffreader = new BufferedReader(new InputStreamReader(System.in));
String fileName = buffreader.readLine();
BufferedReader inStream = new BufferedReader(new FileReader(fileName));
StringBuilder str = new StringBuilder();
int count = 0;
while (inStream.readLine() != null){
str.append(inStream.readLine());
}
while( str.toString().matches("\\bworld\\b") ) { //c:\readme.txt
count++;
str = new StringBuilder(str.substring(str.indexOf("world") + 5));
}
System.out.println(count);
buffreader.close();
inStream.close();
}
}