Develop Reference

Split lines with "," and do a trim on every element [duplicate]

This is some code that I found to help with reading in a 2D Array, but the problem I am having is this will only work when reading a list of number structured like:
73
56
30
75
80
ect..
What I want is to be able to read multiple lines that are structured like this:
1,0,1,1,0,1,0,1,0,1
1,0,0,1,0,0,0,1,0,1
1,1,0,1,0,1,0,1,1,1
I just want to essentially import each line as an array, while structuring them like an array in the text file.
Everything I have read says to use scan.usedelimiter(","); but everywhere I try to use it the program throws straight to the catch that replies "Error converting number". If anyone can help I would greatly appreciate it. I also saw some information about using split for the buffered reader, but I don't know which would be better to use/why/how.
String filename = "res/test.txt"; // Finds the file you want to test.
try{
FileReader ConnectionToFile = new FileReader(filename);
BufferedReader read = new BufferedReader(ConnectionToFile);
Scanner scan = new Scanner(read);
int[][] Spaces = new int[10][10];
int counter = 0;
try{
while(scan.hasNext() && counter < 10)
{
for(int i = 0; i < 10; i++)
{
counter = counter + 1;
for(int m = 0; m < 10; m++)
{
Spaces[i][m] = scan.nextInt();
}
}
}
for(int i = 0; i < 10; i++)
{
//Prints out Arrays to the Console, (not needed in final)
System.out.println("Array" + (i + 1) + " is: " + Spaces[i][0] + ", " + Spaces[i][1] + ", " + Spaces[i][2] + ", " + Spaces[i][3] + ", " + Spaces[i][4] + ", " + Spaces[i][5] + ", " + Spaces[i][6]+ ", " + Spaces[i][7]+ ", " + Spaces[i][8]+ ", " + Spaces[i][9]);
}
}
catch(InputMismatchException e)
{
System.out.println("Error converting number");
}
scan.close();
read.close();
}
catch (IOException e)
{
System.out.println("IO-Error open/close of file" + filename);
}
}

I provide my code here.
public static int[][] readArray(String path) throws IOException {
//1,0,1,1,0,1,0,1,0,1
int[][] result = new int[3][10];
BufferedReader reader = new BufferedReader(new FileReader(path));
String line = null;
Scanner scanner = null;
line = reader.readLine();
if(line == null) {
return result;
}
String pattern = createPattern(line);
int lineNumber = 0;
MatchResult temp = null;
while(line != null) {
scanner = new Scanner(line);
scanner.findInLine(pattern);
temp = scanner.match();
int count = temp.groupCount();
for(int i=1;i<=count;i++) {
result[lineNumber][i-1] = Integer.parseInt(temp.group(i));
}
lineNumber++;
scanner.close();
line = reader.readLine();
}
return result;
}
public static String createPattern(String line) {
char[] chars = line.toCharArray();
StringBuilder pattern = new StringBuilder();;
for(char c : chars) {
if(',' == c) {
pattern.append(',');
} else {
pattern.append("(\\d+)");
}
}
return pattern.toString();
}

The following piece of code snippet might be helpful. The basic idea is to read each line and parse out CSV. Please be advised that CSV parsing is generally hard and mostly requires specialized library (such as CSVReader). However, the issue in hand is relatively straightforward.
try {
String line = "";
int rowNumber = 0;
while(scan.hasNextLine()) {
line = scan.nextLine();
String[] elements = line.split(',');
int elementCount = 0;
for(String element : elements) {
int elementValue = Integer.parseInt(element);
spaces[rowNumber][elementCount] = elementValue;
elementCount++;
}
rowNumber++;
}
} // you know what goes afterwards

Since it is a file which is read line by line, read each line using a delimiter ",".
So Here you just create a new scanner object passing each line using delimter ","
Code looks like this, in first for loop
for(int i = 0; i < 10; i++)
{
Scanner newScan=new Scanner(scan.nextLine()).useDelimiter(",");
counter = counter + 1;
for(int m = 0; m < 10; m++)
{
Spaces[i][m] = newScan.nextInt();
}
}

Use the useDelimiter method in Scanner to set the delimiter to "," instead of the default space character.
As per the sample input given, if the next row in a 2D array begins in a new line, instead of using a ",", multiple delimiters have to be specified.
Example:
scan.useDelimiter(",|\\r\\n");
This sets the delimiter to both "," and carriage return + new line characters.

Why use a scanner for a file? You already have a BufferedReader:
FileReader fileReader = new FileReader(filename);
BufferedReader reader = new BufferedReader(fileReader);
Now you can read the file line by line. The tricky bit is you want an array of int
int[][] spaces = new int[10][10];
String line = null;
int row = 0;
while ((line = reader.readLine()) != null)
{
String[] array = line.split(",");
for (int i = 0; i < array.length; i++)
{
spaces[row][i] = Integer.parseInt(array[i]);
}
row++;
}
The other approach is using a Scanner for the individual lines:
while ((line = reader.readLine()) != null)
{
Scanner s = new Scanner(line).useDelimiter(',');
int col = 0;
while (s.hasNextInt())
{
spaces[row][col] = s.nextInt();
col++;
}
row++;
}
The other thing worth noting is that you're using an int[10][10]; this requires you to know the length of the file in advance. A List<int[]> would remove this requirement.

Search for multiline String in a text file

I have a text file from which i am trying to search for a String which has multiple lines. A single string i am able to search but i need multi line string to be searched.
I have tried to search for single line which is working fine.
public static void main(String[] args) throws IOException
{
File f1=new File("D:\\Test\\test.txt");
String[] words=null;
FileReader fr = new FileReader(f1);
BufferedReader br = new BufferedReader(fr);
String s;
String input="line one";
// here i want to search for multilines as single string like
// String input ="line one"+
// "line two";
int count=0;
while((s=br.readLine())!=null)
{
words=s.split("\n");
for (String word : words)
{
if (word.equals(input))
{
count++;
}
}
}
if(count!=0)
{
System.out.println("The given String "+input+ " is present for "+count+ " times ");
}
else
{
System.out.println("The given word is not present in the file");
}
fr.close();
}
And below are the file contents.
line one
line two
line three
line four

Use the StringBuilder for that, read every line from file and append them to StringBuilder with lineSeparator
StringBuilder lineInFile = new StringBuilder();
while((s=br.readLine()) != null){
lineInFile.append(s).append(System.lineSeparator());
}
Now check the searchString in lineInFile by using contains
StringBuilder searchString = new StringBuilder();
builder1.append("line one");
builder1.append(System.lineSeparator());
builder1.append("line two");
System.out.println(lineInFile.toString().contains(searchString));

More complicated solution from default C (code is based on code from book «The C programming language» )
final String searchFor = "Ich reiß der Puppe den Kopf ab\n" +
"Ja, ich reiß' ich der Puppe den Kopf ab";
int found = 0;
try {
String fileContent = new String(Files.readAllBytes(
new File("puppe-text").toPath()
));
int i, j, k;
for (i = 0; i < fileContent.length(); i++) {
for (k = i, j = 0; (fileContent.charAt(k++) == searchFor.charAt(j++)) && (j < searchFor.length());) {
// nothig
}
if (j == searchFor.length()) {
++found;
}
}
} catch (IOException ignore) {}
System.out.println(found);

Why don't you just normalize all the lines in the file to one string variable and then just count the number of occurrences of the input in the file. I have used Regex to count the occurrences but can be done in any custom way you find suitable.
public static void main(String[] args) throws IOException
{
File f1=new File("test.txt");
String[] words=null;
FileReader fr = new FileReader(f1);
BufferedReader br = new BufferedReader(fr);
String s;
String input="line one line two";
// here i want to search for multilines as single string like
// String input ="line one"+
// "line two";
int count=0;
String fileStr = "";
while((s=br.readLine())!=null)
{
// Normalizing the whole file to be stored in one single variable
fileStr += s + " ";
}
// Now count the occurences
Pattern p = Pattern.compile(input);
Matcher m = p.matcher(fileStr);
while (m.find()) {
count++;
}
System.out.println(count);
fr.close();
}
Use StringBuilder class for efficient string concatenation.

Try with Scanner.findWithinHorizon()
String pathToFile = "/home/user/lines.txt";
String s1 = "line two";
String s2 = "line three";
String pattern = String.join(System.lineSeparator(), s1, s2);
int count = 0;
try (Scanner scanner = new Scanner(new FileInputStream(pathToFile))) {
while (scanner.hasNext()) {
String withinHorizon = scanner.findWithinHorizon(pattern, pattern.length());
if (withinHorizon != null) {
count++;
} else {
scanner.nextLine();
}
}
} catch (FileNotFoundException e) {
e.printStackTrace();
}
System.out.println(count);

Try This,
public static void main(String[] args) throws IOException {
File f1 = new File("./src/test/test.txt");
FileReader fr = new FileReader(f1);
BufferedReader br = new BufferedReader(fr);
String input = "line one";
int count = 0;
String line;
while ((line = br.readLine()) != null) {
if (line.contains(input)) {
count++;
}
}
if (count != 0) {
System.out.println("The given String " + input + " is present for " + count + " times ");
} else {
System.out.println("The given word is not present in the file");
}
fr.close();
}

Counting number of words start with UpperCase letter in strings, java

I have tried to write a Java program that count number of words start with UpperCase in each line separately, like in a txt file, and print the line number next to the number of words start with UpperCase in that line.
I have only come out with how to count the number for a single line using:
Scanner in = new Scanner(System.in);
String s = new String();
System.out.println("Enter a line:");
s = " " + in .nextLine();
char ch;
int count = 0;
for (int i = 1; i < s.length(); i++) {
ch = s.charAt(i);
if (Character.isUpperCase(ch) && (i == 0 || Character.isWhitespace(s.charAt(i - 1)))) {
count++;
}
}
System.out.println("total number of words start with capital letters are :" + count);
I tried to do it on the way I want, but it keep showing me "File is empty":
FileInputStream in = new FileInputStream("io-02.txt");
Scanner inScanner = new Scanner(in);
FileOutputStream out = new FileOutputStream("io-02-out.txt");
PrintWriter pwr = new PrintWriter(out);
int linenumb=0;
String s="";
char c;
int count = 0;
inScanner.useDelimiter("");
for (int i = 1; i < s.length(); i++) {
s = " " + inScanner.nextLine().trim();
c = s.charAt(i);
if (Character.isUpperCase(c) && (i == 0 || Character.isWhitespace(s.charAt(i - 1)))) {
count++;
} else if(s == "\n"){
if(linenumb == 0)
pwr.printf("%6s%35s%n", "Line#", "Number of Uppercase characters");
linenumb++;
pwr.printf("%5d.%35d%n", linenumb, count);
count = 0;
}
}
if(linenumb == 0)
System.out.println("Error: The input file is empty");
else{
linenumb++;
pwr.printf("%5d.%35d%n", linenumb, count);
System.out.println("The file output.txt has been created . . . ");
}
Please help.

Java 8 solution:
import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.File;
import java.nio.charset.StandardCharsets;
import java.nio.file.Files;
final public class UppercaseWordCounter { // https://stackoverflow.com/questions/49193228/counting-number-of-words-start-with-uppercase-letter-in-strings-java
final private static File FILE_WORDS = new File("io-02.txt");
final private static File FILE_RESULTS = new File("io-02-out.txt");
public static void main(final String[] args) {
if (!FILE_WORDS.exists()) {
System.err.println("Input file does not exist: " + FILE_WORDS);
System.exit(1);
}
if (FILE_RESULTS.exists()) {
if (!FILE_RESULTS.delete()) {
System.err.println("Intended output file exists already and can't be deleted: " + FILE_RESULTS);
System.exit(2);
}
}
try (final BufferedReader br = Files.newBufferedReader(FILE_WORDS.toPath(), StandardCharsets.UTF_8);
final BufferedWriter bw = Files.newBufferedWriter(FILE_RESULTS.toPath(), StandardCharsets.UTF_8)) {
int lineCounter = 1;
String line;
while ((line = br.readLine()) != null) {
final int upperCaseWordsInThisLine = countUpperCaseWords(line);
bw.write("Line " + lineCounter + " has " + upperCaseWordsInThisLine + " upper case word" + (upperCaseWordsInThisLine == 1 ? "" : "s") + ".\n");
lineCounter++;
}
} catch (Exception e) {
e.printStackTrace();
}
System.exit(0);
}
private static int countUpperCaseWords(final String line) {
int ret = 0;
final int length = line.length();
boolean newWord = true;
for (int i = 0; i < length; i++) {
final char c = line.charAt(i);
if (" .,;/".indexOf(c) >= 0) {
newWord = true;
} else if (newWord) {
newWord = false;
if (Character.isUpperCase(c)) {
ret++;
}
}
}
return ret;
}
}

Why don't you use a method from Files class, which is available from java 1.7
List<String> lst = Files.readAllLines(Path path, Charset cs)
then you can loop over the lst List checking your condition

JAVA - reading from text file, recognizing new lines

I have a task to read a text file with several lines, after that I need to count every character's UNICODE value, so the sum of "hello" is 532 and for "how are you" is 1059 and so on, every string begins on new line in the .txt document and so far so good.
But for every line I need to print only its own value, and the way my code works, it adds every line's value and I cant get my head around a way to stop it when the end of the lxtine comes so it looks something like:
*read line
*count char values
*add up
*print them
*start over for the next line, and so
import java.io.BufferedReader;
import java.io.FileReader;
import java.io.IOException;
import java.io.Reader;
import java.lang.String;
import java.util.Arrays;
public class SumLines {
public static void main(String[] args) {
String filePath = "/home/lines.txt";
String readLine;
int sum = 0;
try (BufferedReader bufferedReader = new BufferedReader(new FileReader(filePath))) {
while ((readLine = bufferedReader.readLine()) != null) {
char[] array = new char[readLine.length()];
System.out.println(readLine);
for (int i = 0; i < readLine.length(); i++) {
Arrays.fill(array, readLine.trim().charAt(i));
sum += (int) array[i];
System.out.print(sum + " ");
}
}
} catch (IOException e) {
System.out.println("Error.\n Invalid or missing file.");
e.printStackTrace();
}
System.out.println("\n*** final " + sum);
}
}

If I understood correctly, for the input:
hello
how are you
You would like to get something like this as output:
hello 532
how are you 1059
*** final 1591
For this, you need to make some modifications to your code:
In addition to calculating the sum of characters values per line, keep another sum of the total of all lines
For each input line, print the line followed by the sum of character values
You don't need an array at all
It's better to trim the input line once, instead of for every character
Like this:
int total = 0;
try (BufferedReader bufferedReader = new BufferedReader(new FileReader(filePath))) {
String readLine;
while ((readLine = bufferedReader.readLine()) != null) {
String trimmed = readLine.trim();
int sum = 0;
for (int i = 0; i < trimmed.length(); i++) {
sum += (int) trimmed.charAt(i);
}
System.out.println(readLine + " " + sum);
total += sum;
}
} catch (IOException e) {
System.out.println("Error.\n Invalid or missing file.");
e.printStackTrace();
}
System.out.println("\n*** final " + total);

After your for loop, set sum to 0. If you want to print the total sum, then you need another variable, say t.
Like this:
for (int i = 0; i < readLine.length(); i++) {
Arrays.fill(array, readLine.trim().charAt(i));
sum += (int) array[i];
System.out.print(sum + " ");
}
t=t+sum;
sum=0;
Then print t at the end.

A simple solution would be to limit the scope of the sum variable. That way, values will not persist between runs:
import java.io.BufferedReader;
import java.io.FileReader;
import java.io.IOException;
import java.io.Reader;
import java.lang.String;
import java.util.Arrays;
public class SumLines {
public static void main(String[] args) {
String filePath = "/home/lines.txt";
String readLine;
int totalSum = 0;
try (BufferedReader bufferedReader = new BufferedReader(new FileReader(filePath))) {
String readLine;
while ((readLine = bufferedReader.readLine()) != null) {
int sum = 0;
for (int i = 0; i < readLine.length(); i++) {
sum += (int) readLine.charAt(i);
}
System.out.println(readLine + ": " + sum);
totalSum += sum;
}
} catch (IOException e) {
System.out.println("Error.\n Invalid or missing file.");
e.printStackTrace();
}
System.out.println("\n*** final " + totalSum);
}
}
Also, you don't have to use such complicated stuff just to get the Unicode value of a char. I made some improvements.

Have two variables, one for final sum and one for line sum.
public class SumLines {
public static void main(String[] args) {
String filePath = "/home/lines.txt";
String readLine;
int totalSum = 0;
int lineSum = 0
try (BufferedReader bufferedReader = new BufferedReader(new FileReader(filePath))) {
while ((readLine = bufferedReader.readLine()) != null) {
char[] array = new char[readLine.length()];
System.out.println(readLine);
for (int i = 0; i < readLine.length(); i++) {
Arrays.fill(array, readLine.trim().charAt(i));
lineSum += (int) array[i];
System.out.print(lineSum + " ");
}
totalSum += lineSum + totalSum;
lineSum = 0;
}
} catch (IOException e) {
System.out.println("Error.\n Invalid or missing file.");
e.printStackTrace();
}
System.out.println("\n*** final " + totalSum);
}
}

Count the amount of times a string appears in a file

I'm trying to figure out how I would read a file, and then count the amount of times a certain string appears.
This is what my file looks like, it's a .txt:
Test
Test
Test
Test
I want the method to then return how many times it is in the file. Any idea's on how I could go about doing this? I mainly need help with the first part. So if I was searching for the string "Test" I would want it to return 4.
Thanks in advanced! Hope I gave enough info!

Add this method to your class, pass your FileInputStream to it, and it should return the number of words in a file. Keep in mind, this is case sensitive.
public int countWord(String word, FileInputStream fis) {
BufferedReader in = new BufferedReader(new InputStreamReader(fis));
String readLine = "";
int count = 0;
while((readLine = in.readLine()) != null) {
String words = readLine.split(" ");
for(String s : words) {
if(s.equals(word)) count++;
}
return count;
}
Just wrote that now, and it's untested, so let me know if it works. Also, make sure that you understand what I did if this is a homework question.

Here you are:
public int countStringInFile(String stringToLookFor, String fileName){
int count = 0;
try{
FileInputStream fstream = new FileInputStream(fileName);
DataInputStream in = new DataInputStream(fstream);
BufferedReader br = new BufferedReader(new InputStreamReader(in));
String strLine;
while ((strLine = br.readLine()) != null) {
int startIndex = strLine.indexOf(stringToLookFor);
while (startIndex != -1) {
count++;
startIndex = base.indexOf(stringToLookFor,
startIndex +stringToLookFor.length());
}
}
in.close();
}catch (Exception e){//Catch exception if any
System.err.println("Error: " + e.getMessage());
}
return count;
}
Usage: int count = countStringInFile("SomeWordToLookFor", "FileName");

If you have got to the point of reading in each file into a string I would suggest looking at the String method split.
Give it the string code 'Test' and it will return an array of type string - count the number of elements per line. Sum them up to get your total occurrence.
import java.io.*;
public class StringCount {
public static void main(String args[]) throws Exception{
String testString = "Test";
String filePath = "Test.txt";
String strLine;
int numRead=0;
try {
FileInputStream fstream = new FileInputStream(filePath);
DataInputStream in = new DataInputStream(fstream);
BufferedReader br = new BufferedReader(new InputStreamReader(in));
while ((strLine = br.readLine()) != null) {
strLine = strLine + " ";
String [] strArry = strLine.split(testString);
if (strArry.length > 1) {
numRead = numRead + strArry.length - 1;
}
else {
if (strLine == testString) {
numRead++;
}
}
}
in.close();
System.out.println(testString + " was found " + numRead + " times.");
}catch (Exception e){
}
}
}

I would do this:
open and read the file line by line,
check how oft a line contains the given word...
increase a global counter for that..
public static void main(String[] args) throws IOException {
BufferedReader in = new BufferedReader(new FileReader("Test.txt"));
Scanner sc = new Scanner(System.in);
System.out.print("Enter the subtring to look for: ");
String word = sc.next();
String line = in.readLine();
int count = 0;
do {
count += (line.length() - line.replace(word, "").length()) / word.length();
line = in.readLine();
} while (line != null);
System.out.print("There are " + count + " occurrences of " + word + " in ");
}