blocks|key|1699684|text|从源代码来看，它们非常相似。您可以看到以下内容：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1699685|public+final+Buffer+flip()+{
++++limit+=+position;
++++position+=+0;
++++mark+=+-1;
++++return+this;
}

public+final+Buffer+rewind()+{
++++position+=+0;
++++mark+=+-1;
++++return+this;
}|code-block|syntax|javascript|1699686|所以不同之处在于flip将limit设置为position，而rewind不是。假设你分配了一个8字节的缓冲区，你用4个字节填充了缓冲区，然后将位置设置为3，如下所示：|offset|length|style|CODE|1699687|++++[+1++1++1++1++0++0++0++0]
+++++++++++++++%7C+++++++++++%7C
flip+++++++++++limit+++++++%7C
rewind+++++++++++++++++++++limit|1699688|所以rewind刚刚使用的limit已经做了适当设置。|1699689|entityMap^0|0|0|8|4|D|5|L|8|V|6|0|0|2|6|0^^$0|@$1|2|3|4|5|6|7|S|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|T|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|U|8|@$I|V|J|W|K|L]|$I|X|J|Y|K|L]|$I|Z|J|10|K|L]|$I|11|J|12|K|L]]|9|@]|A|$]]|$1|M|3|N|5|D|7|13|8|@]|9|@]|A|$E|F]]|$1|O|3|P|5|6|7|14|8|@$I|15|J|16|K|L]]|9|@]|A|$]]|$1|Q|3|-4|5|6|7|17|8|@]|9|@]|A|$]]]|R|$]]

From the source code, they are very similar. You can see the follow:

<pre><code>public final Buffer flip() {
 limit = position;
 position = 0;
 mark = -1;
 return this;
}

public final Buffer rewind() {
 position = 0;
 mark = -1;
 return this;
}
</code></pre>

So the difference is the <code>flip</code> set the <code>limit</code> to the <code>position</code>, while <code>rewind</code> not. 
Consider you have allocated a buffer with 8 bytes, you have filled the buffer with 4 bytes, then the position is set to 3, just show as follow:

<pre><code> [ 1 1 1 1 0 0 0 0]
 | |
flip limit |
rewind limit
</code></pre>

So <code>rewind</code> just used limit has set appropriately.

blocks|key|1699533|text|它们根本不是等价的。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1699534|ByteBuffer通常已为read()+(或put())做好准备。|offset|length|style|CODE|1699535|flip()为write()+(或get())做好了准备。|1699536|rewind()、compact()和clear()使其在write()+(或get())之后再次为read()/put()做好了准备。|1699537|entityMap^0|0|0|A|E|6|N|5|0|0|6|7|7|H|5|0|0|8|9|9|J|7|T|7|13|5|1E|C|0^^$0|@$1|2|3|4|5|6|7|N|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|O|8|@$D|P|E|Q|F|G]|$D|R|E|S|F|G]|$D|T|E|U|F|G]]|9|@]|A|$]]|$1|H|3|I|5|6|7|V|8|@$D|W|E|X|F|G]|$D|Y|E|Z|F|G]|$D|10|E|11|F|G]]|9|@]|A|$]]|$1|J|3|K|5|6|7|12|8|@$D|13|E|14|F|G]|$D|15|E|16|F|G]|$D|17|E|18|F|G]|$D|19|E|1A|F|G]|$D|1B|E|1C|F|G]|$D|1D|E|1E|F|G]]|9|@]|A|$]]|$1|L|3|-4|5|6|7|1F|8|@]|9|@]|A|$]]]|M|$]]

They're not equivalent at all.

A <code>ByteBuffer</code> is normally ready for <code>read()</code> (or for <code>put()</code>).

<code>flip()</code> makes it ready for <code>write()</code> (or for <code>get()</code>).

<code>rewind()</code> and <code>compact()</code> and <code>clear()</code> make it ready for <code>read()/put()</code> again after <code>write()</code> (or <code>get()</code>).

blocks|key|1699643|text|rewind(+)方法类似于flip(+)，但不影响限制。它只会将位置设置回0。您可以使用rewind(+)返回并重新读取已翻转的缓冲区中的数据。一种常见的情况是:在您使用flip()之后，您从缓冲区读取数据，如果您想要重新读取数据，则此方法将起作用。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1699644|entityMap^0|0^^$0|@$1|2|3|4|5|6|7|D|8|@]|9|@]|A|$]]|$1|B|3|-4|5|6|7|E|8|@]|9|@]|A|$]]]|C|$]]

The rewind( ) method is similar to flip( ) but does not affect the limit. It only sets the position back to 0. You can use rewind( ) to go back and reread the data in a buffer that has already been flipped. A common situation would be : after you use flip(), you read the data from the buffer, the you want to reread the data, this method would work.

blocks|key|1699662|text|这是一个例子，两者会产生不同的结果。正如你所说，两者都将位置设置为0，两者之间的区别是翻转将限制设置为前一个位置。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1699663|所以使用翻转，如果你正在写(+put+)，读的限制(+get+)将成为你写的最后一个元素的位置。如果你试图读取更多的内容，它将抛出一个异常。|1699664|回放使限制保持不变。假设它达到了容量(缓冲区大小)，它将允许您继续读取超出实际写入的数据，在这种情况下，读取缓冲区初始化时使用的初始零。|1699665|ByteBuffer+bb+=+ByteBuffer.allocateDirect(2);
byte+b+=+127;
bb.put(b);
bb.rewind();//or+flip();

System.out.println(bb.get());++//+will+print+127+in+either+case
System.out.println(bb.get());++//+will+print+0+for+rewind,+BufferUnderflow+exception+for+flip|code-block|syntax|javascript|1699666|entityMap^0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|M|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|N|8|@]|9|@]|A|$]]|$1|D|3|E|5|6|7|O|8|@]|9|@]|A|$]]|$1|F|3|G|5|H|7|P|8|@]|9|@]|A|$I|J]]|$1|K|3|-4|5|6|7|Q|8|@]|9|@]|A|$]]]|L|$]]

Here is an example where the two will produce different results.
As you said, both set position to 0, the difference between the two is that flip sets the limit to the previous position.

So with flip, if you were writing ( put ) , the limit for reading ( get ) will become the position of the last element you wrote. If you try to read any more than that, it will throw an exception.

Rewind leaves the limit unchanged. Assuming it was at capacity ( buffer size ) , it will let you keep on reading beyond the data that you actually wrote, in this case reading the initial zeros that the buffer was initialized with.

<pre><code>ByteBuffer bb = ByteBuffer.allocateDirect(2);
byte b = 127;
bb.put(b);
bb.rewind();//or flip();

System.out.println(bb.get()); // will print 127 in either case
System.out.println(bb.get()); // will print 0 for rewind, BufferUnderflow exception for flip
</code></pre>

blocks|key|1699718|text|Buffer具有position、limit和capacity属性。您可以在创建缓冲区时为n个元素分配空间。这里n是容量。分配缓冲区后，位置设置为0，限制设置为容量。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1699719|如果用n-x个元素填充缓冲区，则position将设置为n-x。缓冲区在n-x之后将有空元素。|1699720|如果你想在这一点上清空缓冲区，并且也只想要非空值，你需要将limit+to+current+position和position设置为0。使用hasRemaining()，您可以获取直到n-x的元素。Flip设置limit和position属性，如上所述。|1699721|翻转和倒带之间的区别在于，翻转将位置设置为0，并将限制设置为活动内容。方法倒带只是将位置设置为0。|1699722|有关更多信息，请访问http://www.zoftino.com/java-nio-tutorial|offset|length|1699723|entityMap|0|LINK|mutability|MUTABLE|url|http://www.zoftino.com/java-nio-tutorial^0|0|0|0|0|A|14|0|0^^$0|@$1|2|3|4|5|6|7|T|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|U|8|@]|9|@]|A|$]]|$1|D|3|E|5|6|7|V|8|@]|9|@]|A|$]]|$1|F|3|G|5|6|7|W|8|@]|9|@]|A|$]]|$1|H|3|I|5|6|7|X|8|@]|9|@$J|Y|K|Z|1|10]]|A|$]]|$1|L|3|-4|5|6|7|11|8|@]|9|@]|A|$]]]|M|$N|$5|O|P|Q|A|$R|S]]]]

Buffer has position, limit and capacity properties. You can allocate space for n number of elements while creating a buffer. Here n is the capacity. After buffer is allocated, position is set to 0 and limit is set to capacity.

If you filled the buffer with n-x number of elements, position will be set to n-x. Buffer will have empty elements after n-x.

If you want to drain the buffer at this point and that too want only non empty values, you need set limit to current position and position to zero. Using hasRemaining(), you can get elements till n-x. Flip sets the limit and position properties like described above. 

Difference between flip and rewind is that flip sets the position to 0 and sets limit to active content. Method rewind just sets the position to 0.

For more information <a href="http://www.zoftino.com/java-nio-tutorial" rel="nofollow noreferrer">http://www.zoftino.com/java-nio-tutorial</a>

I am aware that flip() set the current buffer position to 0 and set the limit to the previous buffer position whereas rewind() just set the current buffer position to 0.
In the following code, either I use rewind() or flip() i get the same result.
<pre><code>byte b = 127;
bb.put(b);
bb.rewind();//or flip();

System.out.println(bb.get());
bb.rewind();// or flip();
System.out.println(bb.get());
</code></pre>
Could you provide me with a real example where the difference of these 2 methods really matters? Thanks in advance.

difference between bytebuffer.flip() and bytebuffer.rewind()

翻译质量差，导致语言生硬或混乱。

没有提供实际的解决方法或示例。

解答不清晰，无法理解或解决问题。

页面排版不美观，阅读体验差。

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我知道flip()将当前缓冲区位置设置为0，并将限制设置为前一个缓冲区位置，而rewind()仅将当前缓冲区位置设置为0。在下面的代码中，我使用rewind()或flip()得到相同的结果。byte b = 127;bb.put(b);bb.rewind();//or flip();System.out.println(bb.get());bb.rewind();// or flip();Syst

问bytebuffer.flip()和bytebuffer.rewind()之间的区别
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问bytebuffer.flip()和bytebuffer.rewind()之间的区别
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