输出文件和原文件大小不同

/** 上传文件最大字节 */
private final int BUFFER_SIZE = 1024 * 16;

private void copy(File src, File dst) {

try {
InputStream in = null;
OutputStream out = null;
try {
in = new BufferedInputStream(new FileInputStream(src),BUFFER_SIZE);
out = new BufferedOutputStream(new FileOutputStream(dst),BUFFER_SIZE);
byte[] buffer = new byte[BUFFER_SIZE];
int len; 
while ((len = in.read(buffer)) > 0) {
out.write(buffer,0,len);
}
} finally {
if (null != in) {
in.close();
}
if (null != out) {
out.flush();
out.close();
}
}
} catch (Exception e) {
e.printStackTrace();
}

}

要注意输出时，多余的空间造成 复制出来的文件和原文件大小不同。