JHPeng's Blog：宏觀篇。

public static void copyFile(String originalFileName, String destFileName)
            throws Exception {

        byte[] buffer = new byte[4096];
        int size = -1;

        FileInputStream fis = new FileInputStream(originalFileName);
        FileOutputStream fos = new FileOutputStream(destFileName);

        while ((size = fis.read(buffer, 0, buffer.length)) != -1) {
            fos.write(buffer, 0, size);
        }

        fis.close();
        fos.close();

        fis = null;
        fos = null;

    }

<!-- 往SDCard寫入數據權限 -->
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>

<!-- 在SDCard中創建與刪除文件的權限 -->                    
<uses-permission android:name="android.permission.MOUNT_UNMOUNT_FILESYSTEMS" />

http://getmsg.iteye.com/blog/795616