Java – 行ごとにテキストファイルを読み込む

package com.techfou;

import java.io.IOException;
import java.io.RandomAccessFile;
import java.nio.ByteBuffer;
import java.nio.channels.FileChannel;

public class NIOFileReadExample {

    public static void main(String[]args) throws IOException {

        RandomAccessFile file = new RandomAccessFile("src/com/mkyong/data.txt", "r");

        FileChannel channel = file.getChannel();

        System.out.println("File size is: " + channel.size());

        ByteBuffer buffer = ByteBuffer.allocate((int) channel.size());

        channel.read(buffer);

        buffer.flip();//Restore buffer to position 0 to read it

        System.out.println("Reading content and printing ... ");

        for (int i = 0; i < channel.size(); i++) {
            System.out.print((char) buffer.get());
        }

        channel.close();
        file.close();

    }

}

File size is: 19
Reading content and printing ...
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package com.mkyong;

import java.io.BufferedReader;
import java.io.File;
import java.io.FileReader;
import java.io.IOException;

public class ReadTextFile {

    public static void main(String[]args) throws IOException {

        try {

            File f = new File("src/com/mkyong/data.txt");

            BufferedReader b = new BufferedReader(new FileReader(f));

            String readLine = "";

            System.out.println("Reading file using Buffered Reader");

            while ((readLine = b.readLine()) != null) {
                System.out.println(readLine);
            }

        } catch (IOException e) {
            e.printStackTrace();
        }

    }

}

Reading file using Buffered Reader
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  <dependency>
    <groupId>commons-io</groupId>
    <artifactId>commons-io</artifactId>
    <version>2.5</version>
  </dependency>

package com.mkyong;

import org.apache.commons.io.FileUtils;
import java.io.File;
import java.io.IOException;
import java.util.List;

public class ReadTextFile {

    public static void main(String[]args) throws IOException {

        try {

            File f = new File("src/com/mkyong/data.txt");

            System.out.println("Reading files using Apache IO:");

            List<String> lines = FileUtils.readLines(f, "UTF-8");

            for (String line : lines) {
                System.out.println(line);
            }

        } catch (IOException e) {
            e.printStackTrace();
        }

    }

}

Reading files using Apache IO:
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