java中将一个byte[]数组写成一个二进制文件？

如题：想要将一个byte[]数组大概是1024*8这样大小的一个数组写成一个二进制文件，但是写入的时候发现会有数据丢失，不知道因为什么啊？
下面是代码，请大牛给解答一下，谢谢啦！
OutputStream os;
FileOutputStream fos;
try {
os = new FileOutputStream(file);
BufferedInputStream is = new BufferedInputStream(new ByteArrayInputStream(bs));
int len;
byte[] buf = new byte[1024 * 8];
while ((len = is.read(buf)) != -1) {
Thread.sleep(1000);
os.write(buf);
}
System.out.println("len:"+len);
os.flush();
is.close();
os.close();
System.out.println("写入成功:" + strPath);
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
} catch (InterruptedException e) {
e.printStackTrace();
}

你这个代码有问题呀：

 import java.io.BufferedInputStream;
import java.io.ByteArrayInputStream;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.OutputStream;

public class Test {
    public static void main(String[] args) {
        OutputStream os;
        FileOutputStream fos;
        File file = new File("/home/gongxufan/out");
        try

        {
            os = new FileOutputStream(file);
            int len;
            byte[] buf = new byte[1024 * 8];
            BufferedInputStream is = new BufferedInputStream(new ByteArrayInputStream(buf));
            while ((len = is.read(buf)) != -1) {
                Thread.sleep(1000);
                os.write(buf);
            }
            System.out.println("len:" + len);
            os.flush();
            is.close();
            os.close();
            System.out.println("写入成功:" + file.getAbsolutePath());
        } catch (
                FileNotFoundException e)

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

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

        {
            e.printStackTrace();
        }
    }
}

 gongxufan@gongxufan-ThinkPad-E460 ~ $ ll out 
-rw-rw-r-- 1 gongxufan gongxufan 8192 Nov  6 14:24 out