使用輸入輸出流實現文件複製

        FileInputStream fis = 
                    new FileInputStream("JAVA_SE.rar");
        FileOutputStream fos = 
                    new FileOutputStream("JAVA_SE_COPY.rar");

        long start = System.currentTimeMillis();
        int len = -1;
        byte[] buffer = new byte[512];

        while((len=fis.read(buffer)) != -1){
            fos.write(buffer,0,len);
        }
        fis.close();
        fos.close();
        long end = System.currentTimeMillis();
        System.out.println((end-start) +"毫秒");