@Test

public void test16() throws IOException {

    RandomAccessFile rafR = new RandomAccessFile("FLAMING MOUNTAIN.JPG", "r");

    RandomAccessFile rafW = new RandomAccessFile("FLAMING MOUNTAIN2.JPG", "rw");

    byte[] buffer = new byte[1024];

    int len;

    while ((len = rafR.read(buffer)) != -1){

        rafW.write(buffer, 0, len);

    }

    rafW.close();

    rafR.close();

}

@Test

public void test17() throws IOException {

    RandomAccessFile rafW = new RandomAccessFile("hello.txt", "rw");

    //自动创建文件，逐个覆盖原有文件内容

    rafW.write("xyz".getBytes());

    rafW.close();

}