IO PerformanceTuning - How to read entire contents from a .csv File without using loop(while/do/for)

[rdhinesh kumar]

How to read entire contents from a .csv file without using loop(while/do/for) ?
I have a scenario, which I need to add some string in 1st line of the .csv file. For example, Header Message Text
At end of the line, I need to append some string like footer message. For example, Footer Message Text
So result should be, Header String + Actual Contents from the text file + Footer String


Condition -1
========
I Shouldn't use,

bufferedReader.readLine() 

with any loop conditions

                         String strHeader = "ApplicationID_235987";
                         String strFooter = "EndOfFile_349587rds";
                         String contents = strHeader;
                         bufferedReader = new BufferedReader(new FileReader(C:\Test.csv));
			while ((strTemp = bufferedReader.readLine()) != null) {
				contents = contents + strTemp;
                       }
                        contents  + strFooter ;
                        /////////////////////////////////////////////
                       /// Code to write the file //////
                        ////////////////////////////////////////////

Why because, if the file size is huge, it will take more time to read and cause performance issue.
Consider the comma-separated values file have 25000+ lines. So, file size will be more than 2MB. The loop will keep on execute.
Maximum within 5 minutes, I need to upload this file. Else the app will throw an error.

Conditions - 2
=========
Only to solve this issue, I shouldn't upgrade java version. We are using Java 4 version only.
Actually there is a solution in Java 7

import java.util.List;
import java.nio.charset.Charset;
import java.nio.file.*;
 
public class ReadAll {
	public static List<String> readAllLines(String filesname){
		Path file = Paths.get(filename);
		return Files.readAllLines(file, Charset.defaultCharset());  // with out loop we can read all the contents
	}
 
	public static byte[] readAllBytes(String filename){
		Path file = Paths.get(filename);
		return Files.readAllBytes(file);
	}
}

These 2 condition for performance tuning. The application shouldn't take more than 5 minutes to upload a file.
Within this 5mins I need to alter the content of file and upload a file.

So any solution is there in Java 4 to solve this issue ??

Advise me please...

[Jeff Verdegan]

rdhinesh kumar wrote:How to read entire contents from a .csv file without using loop(while/do/for) ?

Not possible. And why would you want to?

Why because, if the file size is huge, it will take more time to read and cause performance issue.

No.

The I/O is what will take the time, not the looping.