Having alot of trouble in file reading in java

Question

i dont know. but i feel really bad that Java is a very good OOP language and i suck big time (not very bad but got frustrated) in reading and writing files. some of the time i have accomplish my task with the help of forums. anyways first i would like to ask 2 questions and then i will state my problem. say for instance if i have a file with name amount and dollars. how can i read it?
i know i can use string regex split method in order to split the line but how can i create a method to do some changes in the text file like i have a name, bank account # and amount to deposit in the text file. my question is how can i declare my method to read (Name) first column and price second column and amount to deposit the third colum?
Secondly if i have a text file and i would like to replace all <<A>> with the name and <<G>> with the age. if i wanted to do without reading a file no problem create a string and then use the replaceAll method ("<<A>>", "Jaan") but for some reason i can't do it when i read a file. yes i am searching on google to get more understanding in reading file. but anyone care to explain wil be great. God bless you my Son.
import java.io.*;
import java.util.*;
class ReadData {
     private Scanner s;
     private static final String EMPTY_STRING = "";
     private String line1;
     private static String lineTerminator = System.getProperty("line.separator");
     public static void main(String[] args) throws IOException {
          ReadData read = new ReadData();
          read.start();
     public ReadData() {
          s = new Scanner(System.in);
     public void start() throws FileNotFoundException, IOException {
          System.out.println("Enter the file name");
          try {
          String name = s.next();
          openFile(name);
          catch (FileNotFoundException e) {
               e.printStackTrace();
          catch (IOException e) {
               e.printStackTrace();
     public String openFile(String filename) throws FileNotFoundException, IOException {
          String line;
          String line2;
          StringBuffer document = new StringBuffer(EMPTY_STRING);
          File inFile = new File(filename);
          FileReader fileReader = new FileReader(inFile);
          BufferedReader bufReader = new BufferedReader(fileReader);
          while(true) {
               line = bufReader.readLine();
               if(line==null) break;
               document.append(line + lineTerminator);
              System.out.print(document.toString());
          return document.toString();
}

Answer 1

i dont know. but i feel really bad that Java is a
very good OOP language and i suck big time (not very
bad but got frustrated) in reading and writing files.
some of the time i have accomplish my task with the
help of forums. anyways first i would like to ask 2
questions and then i will state my problem. say for
instance if i have a file with name amount and
dollars. how can i read it?Just like you'd read any other file. How you interpret what you've read depends on the specific format of the file, which you've provided no information about.
i know i can use string regex split method in order
to split the line but how can i create a method to do
some changes in the text file like i have a name,
bank account # and amount to deposit in the text
file. my question is how can i declare my method to
read (Name) first column and price second column and
amount to deposit the third colum? What do you mean? You want to read the entire first column, from all lines, then the entire second column, etc.? Unless you know the length of each line ahead of time so you can use RandomAccesFile, you can't do that. If that's not what you mean, then please clarify.
Secondly if i have a text file and i would like to
replace all <<A>> with the name and <<G>> with the
age. if i wanted to do without reading a file no
problem create a string and then use the replaceAll
method ("<<A>>", "Jaan") but for some reason i can't
do it when i read a file.
Create a tmp file.
For each line {
  Read a line.
  Do the replacement on the string you read.
  Write the new line out to the temp file
rename the temp file to the original
anyone care to explain wil be great. God bless you my
Son.I'm not your son. Keep your god away from me.