Method to find string inside of the text file Then getting the following lines up to a certain limit

Question

So this is what I have so far    public String   findStudentInfo String studentNumber                    Student student   new Student                    Scanner scanner   new Scanner  Student txt                       Find the line that contains student Id                    If not found keep on going through the file                    If it finds it stop                    Call parseStudentInfoFromLine get the number of courses                    Create an array  lines  of size of the number of courses plus one                    assign the line that the student Id was found to the first index value of the array                   assign each next line to the following index of the array up to the amount of classes - 1                    return string array     I know how to find if a file contains the string I am trying to find but I don t know how to retrieve the whole line that its in   This is my first time posting so If I have done anything wrong please let me know

User · Accepted Answer

You can do something like this   File file   new File  Student txt     try       Scanner scanner   new Scanner file          now read the file line by line        int lineNum   0      while  scanner hasNextLine              String line   scanner nextLine            lineNum            if  lt some condition is met for the line gt                  System out println  ho hum  i found it on line    lineNum                     catch FileNotFoundException e           handle this

User · Answer

This will find  Mark Sagal  in Student txt  Assuming Student txt contains     Student txt   Amir Amiri Mark Sagal Juan Delacruz      Main java   import java io BufferedReader  import java io FileReader  import java util ArrayList   public class Main       public static void main String   args            final String file    Student txt           String line   null          ArrayList lt String gt  fileContents   new ArrayList lt  gt              try               FileReader fReader   new FileReader file               BufferedReader fileBuff   new BufferedReader fReader               while   line   fileBuff readLine       null                    fileContents add line                             fileBuff close              catch  Exception e                System out println e getMessage                       System out println fileContents contains  Mark Sagal

User · Answer

When you are reading the file  have you considered reading it line by line  This would allow you to check if your line contains the file as your are reading  and you could then perform whatever logic you needed based on that   Scanner scanner   new Scanner  Student txt    String currentLine   while  currentLine   scanner readLine       null        if currentLine indexOf  Your String                     Perform logic           You could use a variable to hold the line number  or you could also have a boolean indicating if you have passed the line that contains your string   Scanner scanner   new Scanner  Student txt    String currentLine  int lineNumber   0  Boolean passedLine   false  while  currentLine   scanner readLine       null        if currentLine indexOf  Your String                     Do task          passedLine   true            if passedLine                 Do other task after passing the line            lineNumber

User · Answer

Here is a java 8 method to find a string in a text file   for  String toFindUrl   urlsToTest            streamService toFindUrl          private void streamService String item            try  Stream lt String gt  stream   Files lines Paths get fileName                 stream filter lines - gt  lines contains item                           forEach System out  println              catch  IOException e                e printStackTrace

User · Answer

I am doing something similar but in C     What you need to do is read the lines in one at a time and parse them  go over the words one by one    I have an outter loop that goes over all the lines and inside that is another loop that goes over all the words   Once the word you need is found  just exit the loop and return a counter or whatever you want   This is my code   It basically parses out all the words and adds them to the  index    The line that word was in is then added to a vector and used to reference the line  contains the name of the file  the entire line and the line number  from the indexed words   ifstream txtFile  txtFile open path  ifstream  in   char line 200     if path is valid AND is not already in the list then add it if txtFile is open    amp  amp   find textFilePaths begin    textFilePaths end    path     textFilePaths end       the path is valid         Add the path to the list of file paths     textFilePaths push back path       int lineNumber   1      while  txtFile eof                  txtFile getline line  200           Line   ln   new Line line  path  lineNumber           lineNumber            myList push back ln           vector lt string gt  words   lineParser ln           for unsigned int i   0  i  lt  words size    i                          index- gt addWord words i   ln                       result   true

User · Answer

Using the Apache Commons IO API https   commons apache org proper commons-io  I was able to establish this using FileUtils readFileToString file  contains stringToFind    The documentation for this function is at https   commons apache org proper commons-io javadocs api-2 4 org apache commons io FileUtils html readFileToString java io File

User · Answer

Here is the code of TextScanner  public class TextScanner            private static void readFile String fileName                try                 File file   new File   opt pol data22 ds data118 0001 0025090290 2014 12 12 0029057983 ds                  Scanner scanner   new Scanner file                 while  scanner hasNext                      System out println scanner next                                   scanner close                  catch  FileNotFoundException e                  e printStackTrace                                         public static void main String   args                if  args length    1                  System err println  usage  java TextScanner1                     file location                  System exit 0                             readFile args 0                It will print text with delimeters

[java] Method to find string inside of the text file. Then getting the following lines up to a certain limit

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