Java 的 SocketChannel.read(ByteBuffer)

Posted 2023-02-24

【中文标题】Java 的 SocketChannel.read(ByteBuffer)

【英文标题】：Java's SocketChannel.read(ByteBuffer)

【发布时间】：2014-02-24 22:49:18

【问题描述】：

似乎无法在 java 文档中找到答案：

SocketChannel.read(ByteBuffer) 是追加还是覆盖当前的ByteBuffer？

【问题讨论】：

Reads a sequence of bytes from this channel into the given buffer. Suppose that a byte sequence of length n is read, where 0 <= n <= r. This byte sequence will be transferred into the buffer so that the first byte in the sequence is at index p and the last byte is at index p + n - 1, where p is the buffer's position at the moment this method is invoked. Upon return the buffer's position will be equal to p + n; its limit will not have changed.

【参考方案1】：

答案在 ReadableByteChannel 的 Javadoc 中，SocketChannel 实现了：

尝试从通道读取最多 r 个字节，其中 r 是在调用此方法时缓冲区中剩余的字节数，即 dst.remaining()。

因此，不，它不会覆盖。