比较 ByteBuffer 内容？

Question

Java 中比较两个 ByteBuffer 的内容以检查是否相等的最简单方法是什么？

Answer 1

您可以检查 equals() 方法也是如此。

告知此缓冲区是否等于另一个对象。

两个字节缓冲区相等当且仅当：

1. 它们具有相同的元素类型，
2. 它们具有相同数量的剩余元素，并且
3. 剩余元素的两个序列（无论其起始位置如何）逐点相等。

字节缓冲区不等于任何其他类型的对象。

Answer 2

或者，使用 JDK/11，还有另一种方法来比较 ByteBuffer 与另一个。主要侧重于查找两者之间不匹配的 API 可以用作 -

int mismatchBetweenTwoBuffers = byteBuffer1.mismatch(byteBuffer2);
if(mismatchBetweenTwoBuffers == -1) {
    System.out.println("The buffers are equal!");
} else {
    System.out.println("The buffers are mismatched at - " + mismatchBetweenTwoBuffers);
}

其文档如下：-

/**
 * Finds and returns the relative index of the first mismatch between this
 * buffer and a given buffer.  The index is relative to the
 * {@link #position() position} of each buffer and will be in the range of
 * 0 (inclusive) up to the smaller of the {@link #remaining() remaining}
 * elements in each buffer (exclusive).
 *
 * <p> If the two buffers share a common prefix then the returned index is
 * the length of the common prefix and it follows that there is a mismatch
 * between the two buffers at that index within the respective buffers.
 * If one buffer is a proper prefix of the other then the returned index is
 * the smaller of the remaining elements in each buffer, and it follows that
 * the index is only valid for the buffer with the larger number of
 * remaining elements.
 * Otherwise, there is no mismatch.
 *
 * @return  The relative index of the first mismatch between this and the
 *          given buffer, otherwise -1 if no mismatch.
 *
 * @since 11
 */
public int mismatch(ByteBuffer that)