44. バイトストリーム

バイナリの書き込み

L:\lesson112\test.java

import java.io.*;

class test {
    public static void main(String args[]) {
        byte ary[] = { 0x41 , 0x42 , 0x43 , 0x44 };

        try {
            FileOutputStream fos = new FileOutputStream("test1.txt");
            fos.write(ary);
            fos.close();

            DataOutputStream dos = new DataOutputStream(new FileOutputStream("test2.txt"));
            dos.writeBoolean(true);
            dos.writeBoolean(false);
            dos.writeInt(1023);
            dos.close();
        }
        catch(IOException e) {
        }
    }
}

実行結果

L:\lesson112>java test

L:\lesson112>type test1.txt
ABCD
L:\lesson112>debug test2.txt

Microsoft (R) KKCFUNC ﾊﾞｰｼﾞｮﾝ 1.10
Copyright (C) Microsoft Corp. 1991,1993. All rights reserved.

KKCFUNC が組み込まれました.

マイクロソフトかな漢字変換ﾊﾞｰｼﾞｮﾝ 2.51
(C)Copyright Microsoft Corp. 1992-1993

2DD8:0100 01 00 00 00 03 FF 00 00-00 00 00 00 00 00 00 00 ................
2DD8:0110 00 00 00 00 00 00 00 00-00 00 00 00 34 00 C7 2D ............4..-
2DD8:0120 00 00 00 00 00 00 00 00-00 00 00 00 00 00 00 00 ................
2DD8:0130 00 00 00 00 00 00 00 00-00 00 00 00 00 00 00 00 ................
2DD8:0140 00 00 00 00 00 00 00 00-00 00 00 00 00 00 00 00 ................
2DD8:0150 00 00 00 00 00 00 00 00-00 00 00 00 00 00 00 00 ................
2DD8:0160 00 00 00 00 00 00 00 00-00 00 00 00 00 00 00 00 ................
2DD8:0170 00 00 00 00 00 00 00 00-00 00 00 00 00 00 00 00 ................

バイナリの読み込み

L:\lesson113\test.java

import java.io.*;

class test {
    public static void main(String args[]) {
        try {
            FileInputStream fis = new FileInputStream(args[0]);
            for (int i = 1; i <= 4; i++)
                System.out.println(fis.read()); // １バイトずつ読み込み
            fis.close();

            DataInputStream dis = new DataInputStream(new FileInputStream(args[0]));
            System.out.println(dis.readInt()); // int型として読み込み
            dis.close();
        }
        catch(IOException e) {}
    }
}

実行結果



L:\lesson113>java test ..\lesson112\test1.txt

65

66

67

68

1094861636