Develop Reference

Java: Read file as long as a new date is found

I want to read the file and add each entry to an arraylist on a date. But the date should also be included.
File Example:
15.09.2002 Hello, this is the first entry.
\t this line, I also need in the first entry.
\t this line, I also need in the first entry.
\t this line, I also need in the first entry.
17.10.2020 And this ist the next entry
I tried this. But the Reader reads only the first Line
public class versuch1 {
public static void main(String[] args) {
ArrayList<String> liste = new ArrayList<String>();
String lastLine = "";
String str_all = "";
String currLine = "";
try {
FileReader fstream = new FileReader("test.txt");
BufferedReader br = new BufferedReader(fstream);
while ((currLine = br.readLine()) != null) {
Pattern p = Pattern
.compile("[0-3]?[0-9].[0-3]?[0-9].(?:[0-9]{2})?[0-9]{2} [0-2]?[0-9]:[0-6]?[0-9]:[0-5]");
Matcher m = p.matcher(currLine);
if (m.find() == true) {
lastLine = currLine;
liste.add(lastLine);
} else if (m.find() == false) {
str_all = currLine + " " + lastLine;
liste.set((liste.indexOf(currLine)), str_all);
}
}
br.close();
} catch (Exception e) {
System.err.println("Error: " + e.getMessage());
}
System.out.print(liste.get(0) + " "+liste.get(1);
}
}

I have solved my problem :)
public class versuch1 {
public static void main(String[] args) {
ArrayList<String> liste = new ArrayList<String>();
String lastLine = "";
String currLine = "";
String str_all = "";
try {
FileReader fstream = new FileReader("test.txt");
BufferedReader br = new BufferedReader(fstream);
currLine = br.readLine();
while (currLine != null) {
Pattern p = Pattern
.compile("[0-3]?[0-9].[0-3]?[0-9].(?:[0-9]{2})?[0-9]{2} [0-2]?[0-9]:[0-6]?[0-9]:[0-5]");
Matcher m = p.matcher(currLine);
if (m.find() == true) {
liste.add(currLine);
lastLine = currLine;
} else if (m.find() == false) {
liste.set((liste.size() - 1), (str_all));
lastLine = str_all;
}
currLine = br.readLine();
str_all = lastLine + currLine;
}
} catch (Exception e) {
System.err.println("Error: " + e.getMessage());
}
System.out.print(liste.get(1) + " ");
}
}

While reading the lines, keep a "current entry".
If the line read begins with a date, then it belongs to a new entry. In this case add the current entry to the list of entries and create a new current entry consisting of the read line.
If the line did not begin with a date, just add it to the current entry.
For this to work, you need to read the first line into the current entry before the loop. And after the loop you need to add the current entry to the list of entries. This in turn only works if there is at least one line and the first line begins with a date. So handle the special case of no lines specially (use if-else). And report an error if the first line does not begin with a date.
Happy coding.

Java word appearence in a text file

For the given text file (text.txt) compute how many times each word appears in the file. The output of the program should be another text file containing on each line a word and then the number of times it appears in the original file. After you finish change the program so that the words in the output file are sorted alphabetically. Do not use maps, use only basic arrays. The thing is displaying me only one word that I enter from keyboard in that text file, but how can I display for all words, not only for one? Thanks
package worddata;
import java.io.IOException;
import java.io.BufferedReader;
import java.io.FileReader;
import java.io.*;
import java.util.ArrayList;
import java.util.List;
import java.util.Scanner;
class WordData {
public FileReader fr = null;
public BufferedReader br =null;
public String [] stringArray;
public int counLine = 0;
public int arrayLength ;
public String s="";
public String stringLine="";
public String filename ="";
public String wordname ="";
public WordData(){
try{
Scanner scan = new Scanner(System.in);
System.out.println("Please enter the filename: ");
filename = scan.nextLine();
Scanner scan2 = new Scanner(System.in);
System.out.println("Please enter a word: ");
wordname = scan.nextLine();
fr = new FileReader(filename);
br = new BufferedReader(fr);
while((s = br.readLine()) != null){
stringLine = stringLine + s;
//System.out.println(s);
stringLine = stringLine + " ";
counLine ++;
}
stringArray = stringLine.split(" ");
arrayLength = stringArray.length;
for (int i = 0; i < arrayLength; i++) {
int c = 1 ;
for (int j = i+1; j < arrayLength; j++) {
if(stringArray[i].equalsIgnoreCase(stringArray[j])){
c++;
for (int j2 = j; j2 < arrayLength; j2++) {
stringArray[j2] = stringArray[j2+1];
arrayLength = arrayLength - 1;
}
if (stringArray[i].equalsIgnoreCase(wordname)){
System.out.println("The word "+wordname+" is present "+c+" times in the specified file.");
}
}
}
}
System.out.println("Total number of lines: "+counLine);
fr.close();
br.close();
}catch (Exception e) {
e.printStackTrace();
}
}
public static void main(String[] args) throws IOException {
Scanner scan = new Scanner(System.in);
OutputStream out = new FileOutputStream("output.txt");
System.out.println("Please enter the filename: ");
String filename = scan.nextLine();
System.out.println("Please enter a word: ");
String wordname = scan.nextLine();
int count = 0;
try (LineNumberReader r = new LineNumberReader(new FileReader(filename))) {
String line;
while ((line = r.readLine()) != null) {
for (String element : line.split(" ")) {
if (element.equalsIgnoreCase(wordname)) {
count++;
System.out.println("Word found at line " + r.getLineNumber());
}
}
}
}
FileReader fileReader = new FileReader(filename);
BufferedReader bufferedReader = new BufferedReader(fileReader);
StringBuffer stringBuffer = new StringBuffer();
String line;
while ((line = bufferedReader.readLine()) != null) {
stringBuffer.append(line);
stringBuffer.append("\n");
}
fileReader.close();
System.out.println("The word " + stringBuffer.toString() + " appears " + count + " times.");
int i;
List<String> ls = new ArrayList<String>();
for (i = 1; i <= 1000; i++) {
String str = null;
str = +i + ":- The word "+wordname+" was found " + count +" times";
ls.add(str);
}
String listString = "";
for (String s : ls) {
listString += s + "\n";
}
FileWriter writer = null;
try {
writer = new FileWriter("final.txt");
writer.write(listString);
writer.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}

The code below does something like you want I think.
it does the following:
read the contents from the input.txt file
Remove punctuation marks from the text
make it one string of words by removing line breaks
Split the text up in words by using space as delimiter
The lambda maps all the words to lowercase then removes whitespace and all empty entries then it...
loops over all words and computes there word count in het HashMap
then we sort the Map based on the count value in reverse order to get the highest counted words first
then write them to a StringBuilder to format it like this "word : count\n" and then write it to a text file
final String content = new String(Files.readAllBytes(Paths.get("<PATH TO YOUR PLACE>/input.txt")));
final List<String> words = Arrays.asList(content.replaceAll("[\\p{InCombiningDiacriticalMarks}]", "").replace("\n", " ").split(" "));
final Map<String, Integer> wordlist = new HashMap<>();
words.stream()
.map(String::toLowerCase)
.map(String::trim)
.filter(s -> !s.isEmpty())
.forEach(s -> {
wordlist.computeIfPresent(s, (s1, integer) -> ++integer);
wordlist.putIfAbsent(s, 1);
});
final StringBuilder sb = new StringBuilder();
wordlist.entrySet()
.stream()
.sorted(Map.Entry.comparingByValue(Collections.reverseOrder()))
.collect(Collectors.toMap(
Map.Entry::getKey,
Map.Entry::getValue,
(e1, e2) -> e1,
LinkedHashMap::new
)).forEach((s, integer) -> sb.append(s).append(" : ").append(integer).append("\n"));
Files.write(Paths.get("<PATH TO YOUR PLACE>/output.txt"), sb.toString().getBytes());
Hope it helps :-)
Note: the <PATH TO YOUR PLACE> needs to be replaced by the fully qualified path to your text file with words.

How to read integers from a file that are separated with semi colon?

So in my codes, I am trying to read a file that is like:
100
22
123;22
123 342;432
but when it outputs it would include the ";" ( ex. 100,22,123;22,123,342;432} ).
I am trying to make the file into an array ( ex. {100,22,123,22,123...} ).
Is there a way to read the file, but ignore the semicolons?
Thanks!
public static void main(String args [])
{
String[] inFile = readFiles("ElevatorConfig.txt");
for ( int i = 0; i <inFile.length; i = i + 1)
{
System.out.println(inFile[i]);
}
System.out.println(Arrays.toString(inFile));
}
public static String[] readFiles(String file)
{
int ctr = 0;
try{
Scanner s1 = new Scanner(new File(file));
while (s1.hasNextLine()){
ctr = ctr + 1;
s1.next();
}
String[] words = new String[ctr];
Scanner s2 = new Scanner(new File(file));
for ( int i = 0 ; i < ctr ; i = i + 1){
words[i] = s2.next();
}
return words;
}
catch(FileNotFoundException e)
{
return null;
}
}

public static String[] readFiles(String file)
{
int ctr = 0;
try{
Scanner s1 = new Scanner(new File(file));
while (s1.hasNextLine()){
ctr = ctr + 1;
s1.next();
}
String[] words = new String[ctr];
Scanner s2 = new Scanner(new File(file));
for ( int i = 0 ; i < ctr ; i = i + 1){
words[i] = s2.next();
}
return words;
}
catch(FileNotFoundException e)
{
return null;
}
}
Replace this by
public static String[] readFiles(String file) {
List<String> retList = new ArrayList<String>();
Scanner s2 = new Scanner(new File(file));
for ( int i = 0 ; i < ctr ; i = i + 1){
String temp = s2.next();
String[] tempArr = se.split(";");
for(int k=0;k<tempArr.length;k++) {
retList.add(tempArr[k]);
}
}
return (String[]) retList.toArray();
}

Use regex. Read the entire file into a String (read each token as a String and append a blank space after each token in the String) and then split it at blank spaces and semi colons.
String x <--- contains all contents of the file
String[] words = x.split("[\\s\\;]+");
The contents of words[] are:
"100", "22", "123", "22", "123", "342", "432"
Remember to parse them to int before using as numbers.

Simple way to use BufferedReader Read line by line then split by ;
public static String[] readFiles(String file)
{
BufferedReader br = new BufferedReader(new FileReader(file)))
StringBuilder sb = new StringBuilder();
String line = br.readLine();
while (line != null) {
sb.append(line);
sb.append(System.lineSeparator());
line = br.readLine();
}
String allfilestring = sb.toString();
String[] array = allfilestring.split(";");
return array;
}

You can use split() to split the string into array according to your requirement using regex.
String s; // string you have read from the file
String[] s1 = s.split(" |;"); // s1 contains the strings separated by space and ";"
Hope it helps

Keep the code for counting the size of the array.
I would just change the way you input your values.
for (int i = 0; i < ctr; i++) {
words[i] = "" + s1.nextInt();
}

Another option is to replace all non digit characters in your complete file string with a space. That way any non number character is ignored.
BufferedReader br = new BufferedReader(new FileReader(file)))
StringBuilder sb = new StringBuilder();
String line = br.readLine();
while (line != null) {
sb.append(line);
line = br.readLine();
}
String str = sb.toString();
str = str.replaceAll("\\D+"," ");
Now you have a string with numbers separated by spaces, we can tokenize them into number strings.
String[] final = str.split("\\s+");
then convert to int datatypes.

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 ");
}

Reading text from file and storing each word from every line into separate variables

I have a .txt file with the following content:
1 1111 47
2 2222 92
3 3333 81
I would like to read line-by-line and store each word into different variables.
For example: When I read the first line "1 1111 47", I would like store the first word "1" into var_1, "1111" into var_2, and "47" into var_3. Then, when it goes to the next line, the values should be stored into the same var_1, var_2 and var_3 variables respectively.
My initial approach is as follows:
import java.io.*;
class ReadFromFile
{
public static void main(String[] args) throws IOException
{
int i;
FileInputStream fin;
try
{
fin = new FileInputStream(args[0]);
}
catch(FileNotFoundException fex)
{
System.out.println("File not found");
return;
}
do
{
i = fin.read();
if(i != -1)
System.out.print((char) i);
} while(i != -1);
fin.close();
}
}
Kindly give me your suggestions. Thank You

public static void main(String[] args) throws IOException {
File file = new File("/path/to/InputFile");
BufferedReader br = new BufferedReader(new InputStreamReader(new FileInputStream(file)));
String line = null;
while( (line = br.readLine())!= null ){
// \\s+ means any number of whitespaces between tokens
String [] tokens = line.split("\\s+");
String var_1 = tokens[0];
String var_2 = tokens[1];
String var_3 = tokens[2];
}
}

try {
BufferedReader fr = new BufferedReader(new InputStreamReader(new FileInputStream(file), "ASCII"));
while(true)
{
String line = fr.readLine();
if(line==null)
break;
String[] words = line.split(" ");//those are your words
}
} catch (FileNotFoundException e) {
e.printStackTrace();
}
catch(IOException e)
{
e.printStackTrace();
}
Hope this Helps!

Check out BufferedReader for reading lines. You'll have to explode the line afterwards using something like StringTokenizer or String's split.

import java.io.*;
import java.util.Scanner;
class Example {
public static void main(String[] args) throws Exception {
File f = new File("main.txt");
StringBuffer txt = new StringBuffer();
FileOutputStream fos = new FileOutputStream(f);
for (int i = 0; i < args.length; i++) {
txt.append(args[i] + " ");
}
fos.write(txt.toString().getBytes());
fos.close();
FileInputStream fis = new FileInputStream("main.txt");
InputStreamReader input = new InputStreamReader(fis);
BufferedReader br = new BufferedReader(input);
String data;
String result = new String();
StringBuffer txt1 = new StringBuffer();
StringBuffer txt2 = new StringBuffer();
File f1 = new File("even.txt");
FileOutputStream fos1 = new FileOutputStream(f1);
File f2 = new File("odd.txt");
FileOutputStream fos2 = new FileOutputStream(f2);
while ((data = br.readLine()) != null) {
result = result.concat(data);
String[] words = data.split(" ");
for (int j = 0; j < words.length; j++) {
if (j % 2 == 0) {
System.out.println(words[j]);
txt1.append(words[j] + " ");
} else {
System.out.println(words[j]);
txt2.append(words[j] + " ");
}
}
}
fos1.write(txt1.toString().getBytes());
fos1.close();
fos2.write(txt2.toString().getBytes());
fos2.close();
br.close();
}
}