com.test.io;
import java.io.File;
import java.io.IOException;
import java.io.RandomAccessFile;
import java.util.Arrays;
public class RafDemo {
public static void main(String[] args)
throws IOException {
File demo =
new File("demo"
);
if (!
demo.exists()) {
demo.mkdir();
}
File file =
new File(demo, "raf.dat"
);
if (!
file.exists()) {
file.createNewFile();
}
RandomAccessFile raf =
new RandomAccessFile(file, "rw"
);
System.out.println(raf.getFilePointer());
raf.write(‘A‘);
//一个char型占两个字节，但是write一次只写入一个字节（A字符的后八位）
System.out.println(raf.getFilePointer());
raf.write(‘B‘
);
int i = 0x7fffffff
;
raf.write(i >>> 24);
//写入i的高八位
raf.write(i >>> 16
);
raf.write(i >> 8
);
raf.write(i);
System.out.println(raf.getFilePointer());
//直接写入一个int
raf.writeInt(i);
String s = "你"
;
byte[] b =
s.getBytes("utf8");
raf.write(b);
System.out.println(raf.length());
//读文件，必须把指针移到头部
raf.seek(0
);
//一次性读取，把文件中的内容都读到字节数组中
byte[] buf =
new byte[(
int) raf.length()];
raf.read(buf);
System.out.println(Arrays.toString(buf));
for (
byte c : buf) {
System.out.print(Integer.toHexString(c & 0xff) + " "
);
}
//关闭文件
raf.close();
}
}
执行结果：
<span style="color: #800080">0</span>
<span style="color: #800080">1</span>
<span style="color: #800080">6</span>
<span style="color: #800080">13</span><span style="color: #000000">
[</span><span style="color: #800080">65</span>, <span style="color: #800080">66</span>, <span style="color: #800080">127</span>, -<span style="color: #800080">1</span>, -<span style="color: #800080">1</span>, -<span style="color: #800080">1</span>, <span style="color: #800080">127</span>, -<span style="color: #800080">1</span>, -<span style="color: #800080">1</span>, -<span style="color: #800080">1</span>, -<span style="color: #800080">28</span>, -<span style="color: #800080">67</span>, -<span style="color: #800080">96</span><span style="color: #000000">]
</span><span style="color: #800080">41</span> <span style="color: #800080">42</span> 7f ff ff ff 7f ff ff ff e4 bd a0
Java—IO流 RandomAccessFile类
标签：main ati ring 数据 hex bytes cep out oid
本文系统来源：http://www.cnblogs.com/tianxintian22/p/6820691.html
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