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Input a text file through command line in java

I am trying to write a program that inputs a text file through the command line and then prints out the number of words in the text file. I've spent around 5 hours on this already. I'm taking an intro class using java.
Here is my code:
import java.util.*;
import java.io.*;
import java.nio.*;
public class WordCounter
{
private static Scanner input;
public static void main(String[] args)
{
if (0 < args.length) {
String filename = args[0];
File file = new File(filename);
}
openFile();
readRecords();
closeFile();
}
public static void openFile()
{
try
{
input = new Scanner(new File(file));
}
catch (IOException ioException)
{
System.err.println("Cannot open file.");
System.exit(1);
}
}
public static void readRecords()
{
int total = 0;
while (input.hasNext()) // while there is more to read
{
total += 1;
}
System.out.printf("The total number of word without duplication is: %d", total);
}
public static void closeFile()
{
if (input != null)
input.close();
}
}
Each way I've tried I get a different error and the most consistent one is "cannot find symbol" for the file argument in
input = new Scanner(new File(file));
I'm also still not entirely sure what the difference between java.io and java.nio is so I have tried using objects from both. I'm sure this is an obvious problem I just can't see it. I've read a lot of similar posts on here and that is where some of my code is from.
I've gotten the program to compile before but then it freezes in command prompt.

java.nio is the New and improved version of java.io. You can use either for this task. I tested the following code in the command line and it seems to work fine. The "cannot find symbol" error message is resolved in the try block. I think you were confusing the compiler by instantiating a File object named file twice. As #dammina answered, you do need to add the input.next(); to the while loop for the Scanner to proceed to the next word.
import java.io.File;
import java.io.IOException;
import java.util.Scanner;
public class WordCounter {
private static Scanner input;
public static void main(String[] args) {
if(args.length == 0) {
System.out.println("File name not specified.");
System.exit(1);
}
try {
File file = new File(args[0]);
input = new Scanner(file);
} catch (IOException ioException) {
System.err.println("Cannot open file.");
System.exit(1);
}
int total = 0;
while (input.hasNext()) {
total += 1;
input.next();
}
System.out.printf("The total number of words without duplication is: %d", total);
input.close();
}
}

Your code is almost correct. Thing is in the while loop you have specified the terminating condition as follows,
while (input.hasNext()) // while there is more to read
However as you are just increment the count without moving to the next word the count just increases by always counting the first word. To make it work just add input.next() into the loop to move to next word in each iteration.
while (input.hasNext()) // while there is more to read
{
total += 1;
input.next();
}

BufferedReader sometimes read text, sometimes doesn't

I'm trying to read from a .java the methods I have on it, also the classes, I'm using taggs to identify them and stored them, the problem is that using BufferedReader sometimes just doesn't work, the buffer skips a lot of lines for a reason that I can't understand, sometimes when checking the file by myself I just put random spaces between lines, and that fixes some parts, but I can't get the Buffer read all my text without skipping anything, my code so far is like this:
public class ReadFile {
public static void main(String[] args) {
int numclas=0,numbase=0,numbaseagr=0,numbmet=0,numag=0;
String mt="//MT";
String[] nomclass2 = new String[10];
String[] nommetodo2 = new String[50];
boolean metodo=false;
BufferedReader in = null;
try {
in = new BufferedReader(new FileReader("\\Program.java"));
String read = null;
while ((read = in.readLine()) != null) {
read = in.readLine();
String[] splited = read.trim().split("\\s+");
for(int i=0;i<splited.length;i++){
System.out.println(splited[i]);
if(splited[i].equals("class")){
nomclass2[numclas]=splited[i+1];
numclas=numclas+1;
}
if (splited[i].equals(mt)){
metodo=true;
}
if (splited[i].equals("public")){
if (splited[i+1].equals("static")){
nommetodo2[numbmet]=splited[i+3];
numbmet=numbmet+1;
}
if (splited[i+1].equals("int")||splited[i+1].equals("double")||splited[i+1].equals("String")||splited[i+1].equals("boolean")){
nommetodo2[numbmet]=splited[i+2];
numbmet=numbmet+1;
}
if (splited[i].equals("int")||splited[i].equals("double")||splited[i].equals("String")||splited[i].equals("boolean")){
nommetodo2[numbmet]=splited[i+1];
numbmet=numbmet+1;
}
metodo=false;
}
if ((splited[i].equals("int")||splited[i].equals("double")||splited[i].equals("String")||splited[i].equals("boolean"))&&metodo){
nommetodo2[numbmet]=splited[i+1];
numbmet=numbmet+1;
metodo=false;
}
}
}
} catch (IOException e) {
System.out.println("There was a problem: " + e);
e.printStackTrace();
} finally {
try {
in.close();
} catch (Exception e) {
}
}
Now let me show you the .java I'm trying to read:
import java.text.DecimalFormat;
import java.io.*;
//Main file of the program 1
public class Program1 {
//MT
public static void main (String args []) {
DecimalFormat format=new DecimalFormat("##.##");
System.out.println("How many data do you want to insert?");
int num=Leer.Int();
Fila lista=new Fila();
Fila lista2=new Fila();
double x=0.0;
for(int i=0;i<num;i++){
x=Leer.Double();
lista.addNum(x);
}
double prom=0.0;
double desv=0.0;
prom=lista.getprom();
desv=lista.getdevst();
System.out.println("The mean for column 1 is: "+format.format(prom));
System.out.println("The Std.Dev for column 1 is: "+format.format(desv));
System.out.println("How many data do you want to insert?");
num=Leer.Int();
x=0.0;
for(int i=0;i<num;i++) {
x=Leer.Double();
lista2.addNum(x);
}
prom=0.0;
desv=0.0;
prom=lista2.getprom();
desv=lista2.getdevst();
System.out.println("The mean for column 2 is: "+format.format(prom));
System.out.println("The Std.Dev for column 2 is: "+format.format(desv));
}
}
And the result when I print the array
Date:
12/12/12
import
java.text.DecimalFormat;
//Main
file
of
the
program
1
//MT
DecimalFormat
format=new
DecimalFormat("##.##");
so on...
See how in the //MT the Buffer skips a lot of lines, a lot of this is happening (see how it ignores the first lines of the program), and I don't know how to fix it, because sometimes when I try to "fix it" and add some spaces in the lines, I get a nullpointer and the program ends.
Any help will be appreciated, thank you.

This is just a partial answer - at the very least your program is skipping every other line:
while ((read = in.readLine()) != null)
will read a line from the file. The line is immediately discarded because the immediately following statement:
read = in.readLine();
reads and processes the next line from the file.
(also, 'splited' should be 'splitted' along with numerous other spelling mistakes but they're not really affecting your program, just it's readability :-))

Reading data from a table & parsing it

My code is designed to read the contents of a text file and check if the contents are entered in a format that is as follows:
john : martin : 2 : 1
and if that format is followed then it will output it in the format:
john [2] | martin [1]
or else it will be counted as an invalid result and the total numbers will not be added to it whereas if the results are in the format then they will get added to the total so with the example it would display the number of vaild results as 1, invalid as 0 and total number as 3.
My question is that my code doesn't work properly as I get this error:
Exception in thread "main" java.util.InputMismatchException
at java.util.Scanner.throwFor(Scanner.java:840)
at java.util.Scanner.next(Scanner.java:1461)
at java.util.Scanner.nextInt(Scanner.java:2091)
at java.util.Scanner.nextInt(Scanner.java:2050)
at reader.main(reader.java:33)
So how would I go about fixing this and reading and displaying the data in thee way that I want? Thanks in advance.
import java.io.FileReader;
import java.io.BufferedReader;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.util.Locale;
import java.util.Scanner;
public class reader {
/**
* #param args
* #throws FileNotFoundException
* #throws FileNotFoundException
* #throws FileNotFoundException when the file cannot be loaded
*/
public static void main(String[] args) throws FileNotFoundException {
String hteam;
String ateam;
int hscore;
int ascore;
Scanner s = new Scanner(new BufferedReader(new FileReader("results2.txt"))).useDelimiter(":");
// create a scanner which scans from a file and splits at each colon
while ( s.hasNext() ) {
hteam = s.next(); // read the home team from the file
ateam = s.next(); // read the away team from the file
hscore = s.nextInt(); //read the home team score from the file
ascore = s.nextInt(); //read the away team score from the file
System.out.print(hteam); // output the line of text to the console
System.out.print(hscore);
System.out.print(ateam);
System.out.println(ascore);
}
System.out.println("\nEOF"); // Output and End Of File message.
}
}

You're looking for s.next() instead of s.nextLine().
hteam = s.nextLine() reads the entire line "john : martin : 2 : 1", leaving nothing left for ateam.
Edit:
As you've said this still isn't working, I'd guess that you have an extra newline at the end of your input file, which is causing s.hasNext() to evaluate to true. This would cause the Scanner to trip up when it's getting the next input line.
Try Scanner s = new Scanner(System.in).useDelimiter("\\s*:\\s*|\\s*\\n\\s*"); to read multiple lines.
See implementation: http://ideone.com/yfiR2S
To verify that a line is in the correct format, I'd (with inspiration from osoblanco's answer) check that there are 4 words and that the last two are integers:
public static boolean verifyFormat(String[] words) {
// see endnote for isInteger()
return words.length == 4 && /*isInteger(words[2]) && isInteger(words[3])*/;
}
public static void main(String[] args) throws FileNotFoundException {
String hteam;
String ateam;
int hscore;
int ascore;
Scanner s = new Scanner(new BufferedReader(
new FileReader("results2.txt"))).useDelimiter("\\s*:\\s*|\\s*\\n\\s*");
while (s.hasNext()) {
String line = s.nextLine();
String[] words = line.split("\\s*:\\s*");
if(verifyFormat(words)) {
hteam = words[0]; // read the home team
ateam = words[1]; // read the away team
hscore = Integer.parseInt(words[2]); //read the home team score
ascore = Integer.parseInt(words[3]); //read the away team score
System.out.print(hteam); // output the line of text to the console
System.out.print(hscore);
System.out.print(ateam);
System.out.println(ascore);
}
}
System.out.println("EOF");
}
isInteger() can be found here.

I think scanning isn't quite what you want here. I would just use a BufferedReader and do ReadLine to handle 1 line each time through the for loop.
Then verify each line by the following:
1) String.split(":") and verify 4 pieces.
String [] linePieces = nextLine.split(":");
if(linePieces.length!=4)
{
//mark invalid, continue loop
}
2) Trim each piece
for(int i =0; i<4; i++)
linePieces[i] = linePieces[i].trim();
3) Verify piece 3 and piece 4 are numbers, Integer.parseInt with try/catch. In the catch block, count that the line is invalid.
try
{
name1=linePieces[0];
name2=linePieces[1];
score1=Integer.parseInt(linePieces[2]);
score2=Integer.parseInt(linePieces[3]);
//count as success and do logic
}catch(NumberFormatException e){
//invalid line
}

Reading a string with new lines from console java

I want to read this string (from console not file) for example:
one two three
four five six
seven eight nine
So I want to read it per line and put every line in an array.
How can I read it? Because if I use scanner, I can only read one line or one word (nextline or next).
what I mean is to read for example : one two trhee \n four five six \n seven eight nine...

You should do by yourself!
There is a similer example:
public class ReadString {
public static void main (String[] args) {
// prompt the user to enter their name
System.out.print("Enter your name: ");
// open up standard input
BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
String userName = null;
// read the username from the command-line; need to use try/catch with the
// readLine() method
try {
userName = br.readLine();
} catch (IOException ioe) {
System.out.println("IO error trying to read your name!");
System.exit(1);
}
System.out.println("Thanks for the name, " + userName);
}
} // end of ReadString class

To answer the question as clarified in the comment on the first answer:
You must call Scanner's nextLine() method once for each line you wish to read. This can be accomplished with a loop. The problem you will inevitably encounter is "How do I know big my result array should be?" The answer is that you cannot know if you do not specify it in the input itself. You can modify your programs input specification to require the number of lines to read like so:
3
One Two Three
Four Five
Six Seven Eight
And then you can read the input with this:
Scanner s = new Scanner(System.in);
int numberOfLinesToRead = new Integer(s.nextLine());
String[] result = new String[numberOfLinesToRead];
String line = "";
for(int i = 0; i < numberOfLinesToRead; i++) { // this loop will be run 3 times, as specified in the first line of input
result[i] = s.nextLine(); // each line of the input will be placed into the array.
}
Alternatively you can use a more advanced data structure called an ArrayList. An ArrayList does not have a set length when you create it; you can simply add information to it as needed, making it perfect for reading input when you don't know how much input there is to read. For example, if we used your original example input of:
one two trhee
four five six
seven eight nine
You can read the input with the following code:
Scanner s = new Scanner(System.in);
ArrayList<String> result = new ArrayList<String>();
String line = "";
while((line = s.nextLine()) != null) {
result.add(line);
}
So, rather than creating an array of a fixed length, we can simply .add() each line to the ArrayList as we encounter it in the input. I recommend you read more about ArrayLists before attempting to use them.
tl;dr: You call next() or nextLine() for each line you want to read using a loop.
More information on loops: Java Loops

Look at this code:
import java.io.File;
import java.io.IOException;
import java.util.Scanner;
public class SearchInputText {
public static void main(String[] args) {
SearchInputText sit = new SearchInputText();
try {
System.out.println("test");
sit.searchFromRecord("input.txt");
System.out.println("test2");
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
private void searchFromRecord(String recordName) throws IOException {
File file = new File(recordName);
Scanner scanner = new Scanner(file);
StringBuilder textFromFile = new StringBuilder();
while (scanner.hasNext()) {
textFromFile.append(scanner.next());
}
scanner.close();
// read input from console, compare the strings and print the result
String word = "";
Scanner scanner2 = new Scanner(System.in);
while (((word = scanner2.nextLine()) != null)
&& !word.equalsIgnoreCase("quit")) {
if (textFromFile.toString().contains(word)) {
System.out.println("The word is on the text file");
} else {
System.out.println("The word " + word
+ " is not on the text file");
}
}
scanner2.close();
}
}

taking integer input in java

I am actually new to java programming and am finding it difficult to take integer input and storing it in variables...i would like it if someone could tell me how to do it or provide with an example like adding two numbers given by the user..

Here's my entry, complete with fairly robust error handling and resource management:
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
/**
* Simple demonstration of a reader
*
* #author jasonmp85
*
*/
public class ReaderClass {
/**
* Reads two integers from standard in and prints their sum
*
* #param args
* unused
*/
public static void main(String[] args) {
// System.in is standard in. It's an InputStream, which means
// the methods on it all deal with reading bytes. We want
// to read characters, so we'll wrap it in an
// InputStreamReader, which can read characters into a buffer
InputStreamReader isReader = new InputStreamReader(System.in);
// but even that's not good enough. BufferedReader will
// buffer the input so we can read line-by-line, freeing
// us from manually getting each character and having
// to deal with things like backspace, etc.
// It wraps our InputStreamReader
BufferedReader reader = new BufferedReader(isReader);
try {
System.out.println("Please enter a number:");
int firstInt = readInt(reader);
System.out.println("Please enter a second number:");
int secondInt = readInt(reader);
// printf uses a format string to print values
System.out.printf("%d + %d = %d",
firstInt, secondInt, firstInt + secondInt);
} catch (IOException ioe) {
// IOException is thrown if a reader error occurs
System.err.println("An error occurred reading from the reader, "
+ ioe);
// exit with a non-zero status to signal failure
System.exit(-1);
} finally {
try {
// the finally block gives us a place to ensure that
// we clean up all our resources, namely our reader
reader.close();
} catch (IOException ioe) {
// but even that might throw an error
System.err.println("An error occurred closing the reader, "
+ ioe);
System.exit(-1);
}
}
}
private static int readInt(BufferedReader reader) throws IOException {
while (true) {
try {
// Integer.parseInt turns a string into an int
return Integer.parseInt(reader.readLine());
} catch (NumberFormatException nfe) {
// but it throws an exception if the String doesn't look
// like any integer it recognizes
System.out.println("That's not a number! Try again.");
}
}
}
}

java.util.Scanner is the best choice for this task.
From the documentation:
For example, this code allows a user to read a number from System.in:
Scanner sc = new Scanner(System.in);
int i = sc.nextInt();
Two lines are all that you need to read an int. Do not underestimate how powerful Scanner is, though. For example, the following code will keep prompting for a number until one is given:
Scanner sc = new Scanner(System.in);
System.out.println("Please enter a number: ");
while (!sc.hasNextInt()) {
System.out.println("A number, please?");
sc.next(); // discard next token, which isn't a valid int
}
int num = sc.nextInt();
System.out.println("Thank you! I received " + num);
That's all you have to write, and thanks to hasNextInt() you won't have to worry about any Integer.parseInt and NumberFormatException at all.
See also
Java Tutorials/Essential Classes/Basic I/O/Scanning and Formatting
Related questions
How do I keep a scanner from throwing exceptions when the wrong type is entered? (java)
How to use Scanner to accept only valid int as input
Other examples
A Scanner can use as its source, among other things, a java.io.File, or a plain String.
Here's an example of using Scanner to tokenize a String and parse into numbers all at once:
Scanner sc = new Scanner("1,2,3,4").useDelimiter(",");
int sum = 0;
while (sc.hasNextInt()) {
sum += sc.nextInt();
}
System.out.println("Sum is " + sum); // prints "Sum is 10"
Here's a slightly more advanced use, using regular expressions:
Scanner sc = new Scanner("OhMyGoodnessHowAreYou?").useDelimiter("(?=[A-Z])");
while (sc.hasNext()) {
System.out.println(sc.next());
} // prints "Oh", "My", "Goodness", "How", "Are", "You?"
As you can see, Scanner is quite powerful! You should prefer it to StringTokenizer, which is now a legacy class.
See also
Java Tutorials/Essential Classes/Regular expressions
regular-expressions.info/Tutorial
Related questions
Scanner vs. StringTokenizer vs. String.Split

you mean input from user
Scanner s = new Scanner(System.in);
System.out.print("Enter a number: ");
int number = s.nextInt();
//process the number

If you are talking about those parameters from the console input, or any other String parameters, use static Integer#parseInt() method to transform them to Integer.