I want my program to display the contents of the file the user inputs with each line preceded with a line number followed by a colon. The line numbering should start at 1.
This is my program so far:
import java.util.*;
import java.io.*;
public class USERTEST {
public static void main(String[] args) throws IOException
{
Scanner keyboard = new Scanner(System.in);
System.out.print("Enter a file name: ");
String filename = keyboard.nextLine();
File file = new File(filename);
Scanner inputFile = new Scanner(file);
String line = inputFile.nextLine();
while (inputFile.hasNext()){
String name = inputFile.nextLine();
System.out.println(name);
}
inputFile.close();
}
}
I can display the contents of the file so far, but I don't know how to display the contents with the line numbers.
Integer i = 0;
while (inputFile.hasNext()) {
i++;
String line = inputFile.nextLine();
System.out.println(i.toString() + ": " + line);
}
You just need to concat an index to your output string.
int i=1;
while (inputFile.hasNext()){
String name = inputFile.nextLine();
System.out.println(i+ ","+name);
i++;
}
int lineNumber=0;
while (inputFile.hasNext()){
String name = inputFile.nextLine();
`System.out.println(lineNumber+ ":"+name);`
linenumber++;
}
Use an int initialized to 1 and increment it every time you read a line, then just output it before the line contents.
What about creating a numerical counter (increased every time you read a line) ... and putting that in front of the string that you are printing?
Related
I've been doing some exercises from my study book, and I can't seem to figure out this specific one. The instructions are: repeat Exercise P7.2, but allow the user to specify the file name on the command line. If the user does not specify any file name, then prompt the user for the name.
Ín P7.2, which I've completed, we were supposed to write a program that reads a file containing text, read each line and send it to the output file, preceded by line numbers. Basically, what I'm wondering is what I'm supposed to do exactly?
This is my code right now:
public static void main(String[] args) {
Scanner input = new Scanner(System.in);
System.out.print("Enter name of file for reading: ");
String fileNameReading = input.next();
System.out.print("Enter name of file for writing: ");
String fileNameWriting = input.next(); om
input.close();
File fileReading = new File(fileNameReading);
Scanner in = null;
File fileWriting = new File(fileNameWriting);
PrintWriter out = null;
try {
in = new Scanner(fileReading);
out = new PrintWriter(fileWriting); fileWriting
} catch (FileNotFoundException e1) {
System.out.println("Files are not found!");
}
int lineNumber = 1;
while (in.hasNextLine()) {
String line = in.nextLine();
out.write(String.format("/* %d */ %s%n", lineNumber, line));
lineNumber++;
}
out.close();
in.close();
System.out.println();
System.out.println("Filen was read and re-written!");
}
I think your exercise just requires a small refactor to use the command line arguments to specify the file for reading:
public static void main(String[] args) {
Scanner input = new Scanner(System.in);
String fileNameReading;
// check if input file were passed as a parameter
if (args != null && args.length > 0) {
fileNameReading = args[0];
}
// if not, then prompt the user for the input filename
else {
System.out.print("Enter name of file for reading: ");
fileNameReading = input.next();
}
System.out.print("Enter name of file for writing: ");
String fileNameWriting = input.next();
// rest of your code as is
}
You would run your code, for example, as:
java YourClass input.txt
Here we pass in the name of the input file as a parameter.
I am attempting to write a program that will take user input ( a long message of characters), store the message and search a text file to see if those words occur in the text file. The problem I am having is that I am only ever able to read in the first string of the message and compare it to the text file. For instance if I type in "learning"; a word in the text file, I will get a result showing that is is found in the file. However if I type "learning is" It will still only return learning as a word found in the file even though "is" is also a word in the text file. My program seems to not be able to read past the blank space. So I suppose my questions is, how do I augment my program to do this and read every word in the file? Would it also be possible for my program to read every word, with or without spaces, in the original message taken from the user, and compare that to the text file?
Thank you
import java.io.*;
import java.util.Scanner;
public class Affine_English2
{
public static void main(String[] args) throws IOException
{
String message = "";
String name = "";
Scanner input = new Scanner(System.in);
Scanner scan = new Scanner(System.in);
System.out.println("Please enter in a message: ");
message = scan.next();
Scanner file = new Scanner(new File("example.txt"));
while(file.hasNextLine())
{
String line = file.nextLine();
for(int i = 0; i < message.length(); i++)
{
if(line.indexOf(message) != -1)
{
System.out.println(message + " is an English word ");
break;
}
}
}
}
}
I recommend you first process the file and build a set of legal English words:
public static void main(String[] args) throws IOException {
Set<String> legalEnglishWords = new HashSet<String>();
Scanner file = new Scanner(new File("example.txt"));
while (file.hasNextLine()) {
String line = file.nextLine();
for (String word : line.split(" ")) {
legalEnglishWords.add(word);
}
}
file.close();
Next, get input from the user:
Scanner input = new Scanner(System.in);
System.out.println("Please enter in a message: ");
String message = input.nextLine();
input.close();
Finally, split the user's input to tokens and check each one if it is a legal word:
for (String userToken : message.split(" ")) {
if (legalEnglishWords.contains(userToken)) {
System.out.println(userToken + " is an English word ");
}
}
}
}
You may try with this. With this solution you can find each word entered by the user in your example.txt file:
public static void main(String[] args) throws IOException
{
String message = "";
String name = "";
Scanner input = new Scanner(System.in);
Scanner scan = new Scanner(System.in);
System.out.println("Please enter in a message: ");
message = scan.nextLine();
Scanner file = new Scanner(new File("example.txt"));
while (file.hasNextLine())
{
String line = file.nextLine();
for (String word : message.split(" "))
{
if (line.contains(word))
{
System.out.println(word + " is an English word ");
}
}
}
}
As Mark pointed out in the comment, change
scan.next();
To:
scan.nextLine();
should work, i tried and works for me.
If you can use Java 8 and Streams API
public static void main(String[] args) throws Exception{ // You need to handle this exception
String message = "";
Scanner input = new Scanner(System.in);
System.out.println("Please enter in a message: ");
message = input.nextLine();
List<String> messageParts = Arrays.stream(message.split(" ")).collect(Collectors.toList());
BufferedReader reader = new BufferedReader(new FileReader("example.txt"));
reader.lines()
.filter( line -> !messageParts.contains(line))
.forEach(System.out::println);
}
You have many solution, but when it comes to find matches I suggest you to take a look to the Pattern and Matcher and use Regular Expression
I haven't fully understood your question, but you could do add something like this (I did not tested the code but the idea should work fine):
public static void main(String[] args) throws IOException{
String message = "";
String name = "";
Scanner input = new Scanner(System.in);
Scanner scan = new Scanner(System.in);
System.out.println("Please enter in a message: ");
message = scan.next();
Scanner file = new Scanner(new File("example.txt"));
String pattern = "";
for(String word : input.split(" ")){
pattern += "(\\b" + word + "\\b)";
}
Pattern r = Pattern.compile(pattern);
while(file.hasNextLine())
{
String line = file.nextLine();
Matcher m = r.matcher(line);
if(m.matches()) {
System.out.println("Word found in: " + line);
}
}
}
I need to write code that reads and does a text analysis of a file. One of the things it needs to do is to count how many words there are in the file. I wrote a method countWords, but when I run the program it returns 0. The text file I am using contains the following:
Ask not what your country can do for you
ask what you can do for your country
So it clearly should return 17 and not 0. What did I do wrong?
public class TextAnalysis {
public static void main (String [] args) throws IOException {
File in01 = new File("a5_testfiles/in01.txt");
Scanner fileScanner = new Scanner(in01);
System.out.println("TEXT FILE STATISTICS");
System.out.println("--------------------");
System.out.println("Length of the longest word: " + longestWord(fileScanner));
System.out.println("Number of words in file wordlist: " );
countWords(fileScanner);
}
public static String longestWord (Scanner s) {
String longest = "";
while (s.hasNext()) {
String word = s.next();
if (word.length() > longest.length()) {
longest = word;
}
}
return (longest.length() + " " + "(\"" + longest + "\")");
}
public static void countWords (Scanner s) throws IOException {
int count = 0;
while(s.hasNext()) {
String word = s.next();
count++;
}
System.out.println(count);
}
try this?
void countWords()
{
String temp;
File path = new File("c:/Bala/");//give ur path
File file = new File(path, "Bala.txt");//give ur filename
FileReader fr = new FileReader(file);
char cbuf[] = new char[(int) file.length()];
fr.read(cbuf);
temp = new String(cbuf);
String count[]=test.split("\\s");
System.out.println("Count:"+t.length);
}
You already read the scanner and reading it again. just create another scanner to use in count words method
fileScanner = new Scanner(<your file object>);
before
countWords(fileScanner);
Hope this helps.
Declare a new scanner for your count words method, the problem lies under s.next(); it reads the next word in your buffer and discard the previous ones, so after you called your longest word method, the scanner buffer has been used up.
hi I have this Java code,
import java.io.*;
import java.util.*;
public class SongWriter
{
public static void main(String[] args)
{
PrintWriter outputStream = null; // Scope must be outside the try/catch structure
try
{
outputStream = new PrintWriter("Song.txt"); // new
FileOutputStream("Song.txt")
}
catch(FileNotFoundException e)
{
System.out.println("Error opening the file Song.txt.");
System.exit(0);
}
System.out.println("\n classical songs has many lines");
System.out.println("\nNow enter the three lines of your Song.");
String line = null;
Scanner keyboard = new Scanner(System.in);
int count;
for (count = 1; count <= 3; count++)
{
System.out.println("\nEnter line " + count + ": ");
line = keyboard.nextLine();
outputStream.println(count + "\t" + line);
}
outputStream.close();
System.out.println("\nYour Song has been written to the file Song.txt.\n");
} // end of main
} // end of class
how do I Adjust the program so it first asks for a name of the file to write to. Use the Scanner class and its next() method. Read in the file name as a string variable after informing the reader the file name should end in the suffix .txt
Eg:- Song with the file names Haiku1.txt, Haiku2.txt and Haiku3.txt.
You almost had it.
Scanner keyboard = new Scanner(System.in);
System.out.println("Enter first file name:");
String first = keyboard.nextLine();
System.out.println("Enter second file name:");
String second = keyboard.nextLine();
System.out.println("Enter third file name:");
String third = keyboard.nextLine();
//and so on and continue whatever you want to do..
EDIT: After your comment.
First store the 3 lines in a StringBuilder and then ask for the file name to write. Now you have the lyrics and file name.
Using the Scanner class to get input from the user:
String fileName1;
Scanner keyboard = new Scanner(System.in); //creates Scanner object
System.out.print ("Enter the name of the file. The file should end in the suffix .txt") //prompt the user to enter the file name
fileName1 = keyboard.next(); //store the name of the file
You should do this before the try/catch block so that you can use the filename that the user entered instead hardcoding it (like you did here with song.txt).
You can prompt the user this way for as many file names as you need.
I am creating a simple program that counts the number of words, lines and total characters (not including whitespace) in a paper. It is a very simple program. My file compiles but when I run it I get this error:
Exception in thread "main" java.util.NoSuchElementException
at java.util.Scanner.throwFor(Scanner.java:838)
at java.util.Scanner.next(Scanner.java:1347)
at WordCount.wordCounter(WordCount.java:30)
at WordCount.main(WordCount.java:16)
Does anyone know why this is happening?
import java.util.*;
import java.io.*;
public class WordCount {
//throws the exception
public static void main(String[] args) throws FileNotFoundException {
//calls on each counter method and prints each one
System.out.println("Number of Words: " + wordCounter());
System.out.println("Number of Lines: " + lineCounter());
System.out.println("Number of Characters: " + charCounter());
}
//static method that counts words in the text file
public static int wordCounter() throws FileNotFoundException {
//inputs the text file
Scanner input = new Scanner(new File("words.txt"));
int countWords = 0;
//while there are more lines
while (input.hasNextLine()) {
//goes to each next word
String word = input.next();
//counts each word
countWords++;
}
return countWords;
}
//static method that counts lines in the text file
public static int lineCounter() throws FileNotFoundException {
//inputs the text file
Scanner input2 = new Scanner(new File("words.txt"));
int countLines = 0;
//while there are more lines
while (input2.hasNextLine()) {
//casts each line as a string
String line = input2.nextLine();
//counts each line
countLines++;
}
return countLines;
}
//static method that counts characters in the text file
public static int charCounter() throws FileNotFoundException {
//inputs the text file
Scanner input3 = new Scanner(new File("words.txt"));
int countChar = 0;
int character = 0;
//while there are more lines
while(input3.hasNextLine()) {
//casts each line as a string
String line = input3.nextLine();
//goes through each character of the line
for(int i=0; i < line.length(); i++){
character = line.charAt(i);
//if character is not a space (gets rid of whitespace)
if (character != 32){
//counts each character
countChar++;
}
}
}
return countChar;
}
}
I can't really say the exact reason for the problem without looking at the file (Maybe even not then).
while (input.hasNextLine()) {
//goes to each next word
String word = input.next();
//counts each word
countWords++;
}
Is your problem. If you are using the input.hasNextLine() in the while conditional statement use input.nextLine(). Since you are using input.next() you should use input.hasNext() in the while loops conditional statement.
public static int wordCounter() throws FileNotFoundException
{
Scanner input = new Scanner(new File("words.txt"));
int countWords = 0;
while (input.hasNextLine()) {
if(input.hasNext()) {
String word = input.next();
countWords++;
}
}
return countWords;
}
I have just added an if condition within the while loop. Just make sure to check there are token to be parsed. I have changed only in this place. Just make sure to change wherever needed.
This link will give good info. in regard to that.
Hope it was helpful. :)