File vs RandomAccessFile
TIP
File 为顺序读取，RandomAccessFile可以任意读取。
区别
如果想跳过前100K后，再获取5K的数据。
File需要先读取前100K，再读取5K数据；
RandomAccessFile可以直接跳到第101K，读取5K数据。
引用&参考
A random access file is a file where you can "jump" to anywhere within it without having to read sequentially until the position you are interested in. For example, say you have a 1MB file, and you are interested in 5 bytes that start after 100k of data. A random access file will allow you to "jump" to the 100k-th position in one operation. A non-random access file will require you to read 100k bytes first, and only then read the data you're interested in. Hope that helps. Clarification: this description is language-agnostic and does not relate to any specific file wrapper in any specific language/framework.