JAVA EE: Java Tutorial : Java IO (LineNumberReader Constructor accepts reader and buffer size)

Thursday 22 September 2016

Java Tutorial : Java IO (LineNumberReader Constructor accepts reader and buffer size)

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https://www.youtube.com/watch?v=J2V7ttOFDuQ&list=UUhwKlOVR041tngjerWxVccw

myfile.txt

Welcome
Hello
Bye

LineNumberReaderDemo.java

import java.io.FileReader;
import java.io.LineNumberReader;

/*
 * public LineNumberReader(Reader in, int sz)
 * 
 * Parameters:
 * ----------
 * 
 * in - A Reader object to provide the underlying stream. 
 * sz - An int specifying the size of the buffer.
 */
public class LineNumberReaderDemo
{

    public static void main(String[] args) throws Exception
    {
        LineNumberReader lineNumberReader = null;
        FileReader fileReader = null;
        try
        {
            int bufferSize = 1024;
            fileReader = new FileReader("myfile.txt");
            /*
             * Create a new line-numbering reader, reading
             * characters into a buffer of the given size.
             */
            lineNumberReader = new LineNumberReader(fileReader, bufferSize);

            String line;
            while ((line = lineNumberReader.readLine()) != null)
            {
                int lineNumber = lineNumberReader.getLineNumber();
                System.out.println(lineNumber + "." + line);
            }
        }
        finally
        {
            if (lineNumberReader != null)
            {
                /*
                 * When you are finished reading characters
                 * from the LineNumberReader you should
                 * remember to close it. Closing a
                 * LineNumberReader will also close the
                 * Reader instance from which the
                 * LineNumberReader is reading.
                 */
                lineNumberReader.close();
            }
        }
    }
}