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<TITLE>Getting Bytes from a ByteBuffer
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<h3>
e159.
Getting Bytes from a ByteBuffer</h3>
A <code>ByteBuffer</code> has a capacity that determines how many bytes it
contains. This capacity can never change. Any byte in the buffer can
be retrieved using the absolute version of <code>get()</code>, which takes an index
in the range [0..capacity-1].
<P> The bytes in a <code>ByteBuffer</code> can also be retrieved using the
relative version of <code>get()</code>, which uses the position and limit
properties of the buffer. In particular, this version of <code>get()</code>
retrieves the byte at the position and advances the position by
one. <code>get()</code> cannot retrieve bytes past the limit (even though the
limit might be less than the capacity). The position is always <=
limit and limit is always <= capacity.
<pre>
// Create an empty ByteBuffer with a 10 byte capacity
ByteBuffer bbuf = ByteBuffer.allocate(<font color="#0066ff"><i>10</i></font>);
// Get the ByteBuffer's capacity
int capacity = bbuf.capacity(); // 10
// Use the absolute get().
// This method does not affect the position.
byte b = bbuf.get(<font color="#0066ff"><i>5</i></font>); // position=0
// Set the position
bbuf.position(<font color="#0066ff"><i>5</i></font>);
// Use the relative get()
b = bbuf.get();
// Get the new position
int pos = bbuf.position(); // 6
// Get remaining byte count
int rem = bbuf.remaining(); // 4
// Set the limit
bbuf.limit(7); // remaining=1
// This convenience method sets the position to 0
bbuf.rewind(); // remaining=7
</pre>
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Related Examples
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e158. <a class="eglink" href="CreateBuf.html?l=rel">
Creating a ByteBuffer
</a>
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e160. <a class="eglink" href="PutBytes.html?l=rel">
Putting Bytes into a ByteBuffer
</a>
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e161. <a class="eglink" href="Buf2Array.html?l=rel">
Converting Between a ByteBuffer an a Byte Array
</a>
<br>
e162. <a class="eglink" href="GetSetTypes.html?l=rel">
Getting and Setting Non-Byte Java Types in a ByteBuffer
</a>
<br>
e163. <a class="eglink" href="TypeBuf.html?l=rel">
Creating a Non-Byte Java Type Buffer on a ByteBuffer
</a>
<br>
e164. <a class="eglink" href="PutString.html?l=rel">
Using a ByteBuffer to Store Strings
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e165. <a class="eglink" href="SetOrder.html?l=rel">
Setting the Byte Ordering for a ByteBuffer
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See also:
<a class="eglink" href="/egs/java.nio/pkg.html?l=rel#File%20Locking">
File Locking
</a>
<a class="eglink" href="/egs/java.nio/pkg.html?l=rel#Files">
Files
</a>
<a class="eglink" href="/egs/java.nio/pkg.html?l=rel#Sockets">
Sockets
</a>
<a class="eglink" href="/egs/java.nio/pkg.html?l=rel#Streams">
Streams
</a>
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