/* * Copyright (c) 2000, 2011, Oracle and/or its affiliates. All rights reserved. * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. * * This code is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License version 2 only, as * published by the Free Software Foundation. Oracle designates this * particular file as subject to the "Classpath" exception as provided * by Oracle in the LICENSE file that accompanied this code. * * This code is distributed in the hope that it will be useful, but WITHOUT * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License * version 2 for more details (a copy is included in the LICENSE file that * accompanied this code). * * You should have received a copy of the GNU General Public License version * 2 along with this work; if not, write to the Free Software Foundation, * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. * * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA * or visit www.oracle.com if you need additional information or have any * questions. */ #warn This file is preprocessed before being compiled package java.nio; #if[char] import java.io.IOException; #end[char] /** * $A$ $type$ buffer. * *
This class defines {#if[byte]?six:four} categories of operations upon * $type$ buffers: * *
Absolute and relative {@link #get() get} and
* {@link #put($type$)
put} methods that read and write
* single $type$s;
Relative {@link #get($type$[]) bulk get}
* methods that transfer contiguous sequences of $type$s from this buffer
* into an array; {#if[!byte]?and}
Relative {@link #put($type$[]) bulk put}
* methods that transfer contiguous sequences of $type$s from $a$
* $type$ array{#if[char]?, a string,} or some other $type$
* buffer into this buffer;{#if[!byte]? and}
Absolute and relative {@link #getChar() get}
* and {@link #putChar(char)
put} methods that read and
* write values of other primitive types, translating them to and from
* sequences of bytes in a particular byte order;
Methods for creating view buffers, * which allow a byte buffer to be viewed as a buffer containing values of * some other primitive type; and
Methods for {@link #compact compacting}, {@link
* #duplicate
duplicating}, and {@link #slice
*
slicing} $a$ $type$ buffer.
$Type$ buffers can be created either by {@link #allocate
* allocation A byte buffer is either direct or non-direct. Given a
* direct byte buffer, the Java virtual machine will make a best effort to
* perform native I/O operations directly upon it. That is, it will attempt to
* avoid copying the buffer's content to (or from) an intermediate buffer
* before (or after) each invocation of one of the underlying operating
* system's native I/O operations.
*
* A direct byte buffer may be created by invoking the {@link
* #allocateDirect(int) allocateDirect} factory method of this class. The
* buffers returned by this method typically have somewhat higher allocation
* and deallocation costs than non-direct buffers. The contents of direct
* buffers may reside outside of the normal garbage-collected heap, and so
* their impact upon the memory footprint of an application might not be
* obvious. It is therefore recommended that direct buffers be allocated
* primarily for large, long-lived buffers that are subject to the underlying
* system's native I/O operations. In general it is best to allocate direct
* buffers only when they yield a measureable gain in program performance.
*
* A direct byte buffer may also be created by {@link
* java.nio.channels.FileChannel#map Whether a byte buffer is direct or non-direct may be determined by
* invoking its {@link #isDirect isDirect} method. This method is provided so
* that explicit buffer management can be done in performance-critical code.
*
*
*
* This class defines methods for reading and writing values of all other
* primitive types, except boolean. Primitive values are translated
* to (or from) sequences of bytes according to the buffer's current byte
* order, which may be retrieved and modified via the {@link #order order}
* methods. Specific byte orders are represented by instances of the {@link
* ByteOrder} class. The initial order of a byte buffer is always {@link
* ByteOrder#BIG_ENDIAN BIG_ENDIAN}.
*
* For access to heterogeneous binary data, that is, sequences of values of
* different types, this class defines a family of absolute and relative
* get and put methods for each type. For 32-bit floating-point
* values, for example, this class defines:
*
* Corresponding methods are defined for the types char,
* short, int, long, and double. The index
* parameters of the absolute get and put methods are in terms of
* bytes rather than of the type being read or written.
*
*
*
* For access to homogeneous binary data, that is, sequences of values of
* the same type, this class defines methods that can create views of a
* given byte buffer. A view buffer is simply another buffer whose
* content is backed by the byte buffer. Changes to the byte buffer's content
* will be visible in the view buffer, and vice versa; the two buffers'
* position, limit, and mark values are independent. The {@link
* #asFloatBuffer() asFloatBuffer} method, for example, creates an instance of
* the {@link FloatBuffer} class that is backed by the byte buffer upon which
* the method is invoked. Corresponding view-creation methods are defined for
* the types char, short, int, long, and
* double.
*
* View buffers have three important advantages over the families of
* type-specific get and put methods described above:
*
* A view buffer is indexed not in terms of bytes but rather in terms
* of the type-specific size of its values; A view buffer provides relative bulk get and put
* methods that can transfer contiguous sequences of values between a buffer
* and an array or some other buffer of the same type; and A view buffer is potentially much more efficient because it will
* be direct if, and only if, its backing byte buffer is direct. The byte order of a view buffer is fixed to be that of its byte buffer
* at the time that the view is created. Like a byte buffer, $a$ $type$ buffer is either direct or non-direct. A
* $type$ buffer created via the wrap methods of this class will
* be non-direct. $A$ $type$ buffer created as a view of a byte buffer will
* be direct if, and only if, the byte buffer itself is direct. Whether or not
* $a$ $type$ buffer is direct may be determined by invoking the {@link
* #isDirect isDirect} method. This class implements the {@link CharSequence} interface so that
* character buffers may be used wherever character sequences are accepted, for
* example in the regular-expression package {@link java.util.regex}.
* Methods in this class that do not otherwise have a value to return are
* specified to return the buffer upon which they are invoked. This allows
* method invocations to be chained.
*
#if[byte]
*
* The sequence of statements
*
* The new buffer's position will be zero, its limit will be its
* capacity, its mark will be undefined, and each of its elements will be
* initialized to zero. Whether or not it has a
* {@link #hasArray The new buffer's position will be zero, its limit will be its
* capacity, its mark will be undefined, and each of its elements will be
* initialized to zero. It will have a {@link #array
* The new buffer will be backed by the given $type$ array;
* that is, modifications to the buffer will cause the array to be modified
* and vice versa. The new buffer's capacity will be
* array.length, its position will be offset, its limit
* will be offset + length, and its mark will be undefined. Its
* {@link #array }, which allocates space for the buffer's
*
#if[byte]
*
* content, or by {@link #wrap($type$[])
wrapping} an
* existing $type$ array {#if[char]?or string} into a buffer.
*
#else[byte]
*
* content, by {@link #wrap($type$[])
wrapping} an existing
* $type$ array {#if[char]?or string} into a buffer, or by creating a
* view of an existing byte buffer.
*
#end[byte]
*
#if[byte]
*
*
*
mapping Direct vs. non-direct buffers
*
* } a region of a file
* directly into memory. An implementation of the Java platform may optionally
* support the creation of direct byte buffers from native code via JNI. If an
* instance of one of these kinds of buffers refers to an inaccessible region
* of memory then an attempt to access that region will not change the buffer's
* content and will cause an unspecified exception to be thrown either at the
* time of the access or at some later time.
*
*
backing array Access to binary data
*
*
*
*
* float {@link #getFloat()}
* float {@link #getFloat(int) getFloat(int index)}
* void {@link #putFloat(float) putFloat(float f)}
* void {@link #putFloat(int,float) putFloat(int index, float f)}
*
*
*
* Invocation chaining
#end[byte]
*
*
*
* can, for example, be replaced by the single statement
*
*
* bb.putInt(0xCAFEBABE);
* bb.putShort(3);
* bb.putShort(45);
*
#end[byte]
#if[char]
*
* The sequence of statements
*
*
* bb.putInt(0xCAFEBABE).putShort(3).putShort(45);
*
* can, for example, be replaced by the single statement
*
*
* cb.put("text/");
* cb.put(subtype);
* cb.put("; charset=");
* cb.put(enc);
*
#end[char]
*
*
* @author Mark Reinhold
* @author JSR-51 Expert Group
* @since 1.4
*/
public abstract class $Type$Buffer
extends Buffer
implements Comparable<$Type$Buffer>{#if[char]?, Appendable, CharSequence, Readable}
{
// These fields are declared here rather than in Heap-X-Buffer in order to
// reduce the number of virtual method invocations needed to access these
// values, which is especially costly when coding small buffers.
//
final $type$[] hb; // Non-null only for heap buffers
final int offset;
boolean isReadOnly; // Valid only for heap buffers
// Creates a new buffer with the given mark, position, limit, capacity,
// backing array, and array offset
//
$Type$Buffer(int mark, int pos, int lim, int cap, // package-private
$type$[] hb, int offset)
{
super(mark, pos, lim, cap);
this.hb = hb;
this.offset = offset;
}
// Creates a new buffer with the given mark, position, limit, and capacity
//
$Type$Buffer(int mark, int pos, int lim, int cap) { // package-private
this(mark, pos, lim, cap, null, 0);
}
#if[byte]
/**
* Allocates a new direct $type$ buffer.
*
*
* cb.put("text/").put(subtype).put("; charset=").put(enc);
} is unspecified.
*
* @param capacity
* The new buffer's capacity, in $type$s
*
* @return The new $type$ buffer
*
* @throws IllegalArgumentException
* If the capacity is a negative integer
*/
public static $Type$Buffer allocateDirect(int capacity) {
return new Direct$Type$Buffer(capacity);
}
#end[byte]
/**
* Allocates a new $type$ buffer.
*
*
backing array}, and its {@link #arrayOffset
array
* offset} will be zero.
*
* @param capacity
* The new buffer's capacity, in $type$s
*
* @return The new $type$ buffer
*
* @throws IllegalArgumentException
* If the capacity is a negative integer
*/
public static $Type$Buffer allocate(int capacity) {
if (capacity < 0)
throw new IllegalArgumentException();
return new Heap$Type$Buffer(capacity, capacity);
}
/**
* Wraps $a$ $type$ array into a buffer.
*
*
backing array} will be the given array, and
* its {@link #arrayOffset
array offset} will be zero.
The new buffer will be backed by the given $type$ array;
* that is, modifications to the buffer will cause the array to be modified
* and vice versa. The new buffer's capacity and limit will be
* array.length, its position will be zero, and its mark will be
* undefined. Its {@link #array backing array} will be the
* given array, and its {@link #arrayOffset
array offset} will
* be zero.
The content of the new, read-only buffer will be the content of the * given character sequence. The buffer's capacity will be * csq.length(), its position will be start, its limit * will be end, and its mark will be undefined.
* * @param csq * The character sequence from which the new character buffer is to * be created * * @param start * The index of the first character to be used; * must be non-negative and no larger than csq.length(). * The new buffer's position will be set to this value. * * @param end * The index of the character following the last character to be * used; must be no smaller than start and no larger * than csq.length(). * The new buffer's limit will be set to this value. * * @return The new character buffer * * @throws IndexOutOfBoundsException * If the preconditions on the start and end * parameters do not hold */ public static CharBuffer wrap(CharSequence csq, int start, int end) { try { return new StringCharBuffer(csq, start, end); } catch (IllegalArgumentException x) { throw new IndexOutOfBoundsException(); } } /** * Wraps a character sequence into a buffer. * *The content of the new, read-only buffer will be the content of the * given character sequence. The new buffer's capacity and limit will be * csq.length(), its position will be zero, and its mark will be * undefined.
* * @param csq * The character sequence from which the new character buffer is to * be created * * @return The new character buffer */ public static CharBuffer wrap(CharSequence csq) { return wrap(csq, 0, csq.length()); } #end[char] /** * Creates a new $type$ buffer whose content is a shared subsequence of * this buffer's content. * *The content of the new buffer will start at this buffer's current * position. Changes to this buffer's content will be visible in the new * buffer, and vice versa; the two buffers' position, limit, and mark * values will be independent. * *
The new buffer's position will be zero, its capacity and its limit * will be the number of $type$s remaining in this buffer, and its mark * will be undefined. The new buffer will be direct if, and only if, this * buffer is direct, and it will be read-only if, and only if, this buffer * is read-only.
* * @return The new $type$ buffer */ public abstract $Type$Buffer slice(); /** * Creates a new $type$ buffer that shares this buffer's content. * *The content of the new buffer will be that of this buffer. Changes * to this buffer's content will be visible in the new buffer, and vice * versa; the two buffers' position, limit, and mark values will be * independent. * *
The new buffer's capacity, limit, position, and mark values will be * identical to those of this buffer. The new buffer will be direct if, * and only if, this buffer is direct, and it will be read-only if, and * only if, this buffer is read-only.
* * @return The new $type$ buffer */ public abstract $Type$Buffer duplicate(); /** * Creates a new, read-only $type$ buffer that shares this buffer's * content. * *The content of the new buffer will be that of this buffer. Changes * to this buffer's content will be visible in the new buffer; the new * buffer itself, however, will be read-only and will not allow the shared * content to be modified. The two buffers' position, limit, and mark * values will be independent. * *
The new buffer's capacity, limit, position, and mark values will be * identical to those of this buffer. * *
If this buffer is itself read-only then this method behaves in * exactly the same way as the {@link #duplicate duplicate} method.
* * @return The new, read-only $type$ buffer */ public abstract $Type$Buffer asReadOnlyBuffer(); // -- Singleton get/put methods -- /** * Relative get method. Reads the $type$ at this buffer's * current position, and then increments the position. * * @return The $type$ at the buffer's current position * * @throws BufferUnderflowException * If the buffer's current position is not smaller than its limit */ public abstract $type$ get(); /** * Relative put method (optional operation). * *Writes the given $type$ into this buffer at the current * position, and then increments the position.
* * @param $x$ * The $type$ to be written * * @return This buffer * * @throws BufferOverflowException * If this buffer's current position is not smaller than its limit * * @throws ReadOnlyBufferException * If this buffer is read-only */ public abstract $Type$Buffer put($type$ $x$); /** * Absolute get method. Reads the $type$ at the given * index. * * @param index * The index from which the $type$ will be read * * @return The $type$ at the given index * * @throws IndexOutOfBoundsException * If index is negative * or not smaller than the buffer's limit */ public abstract $type$ get(int index); /** * Absolute put method (optional operation). * *Writes the given $type$ into this buffer at the given * index.
* * @param index * The index at which the $type$ will be written * * @param $x$ * The $type$ value to be written * * @return This buffer * * @throws IndexOutOfBoundsException * If index is negative * or not smaller than the buffer's limit * * @throws ReadOnlyBufferException * If this buffer is read-only */ public abstract $Type$Buffer put(int index, $type$ $x$); // -- Bulk get operations -- /** * Relative bulk get method. * *This method transfers $type$s from this buffer into the given * destination array. If there are fewer $type$s remaining in the * buffer than are required to satisfy the request, that is, if * length > remaining(), then no * $type$s are transferred and a {@link BufferUnderflowException} is * thrown. * *
Otherwise, this method copies length $type$s from this * buffer into the given array, starting at the current position of this * buffer and at the given offset in the array. The position of this * buffer is then incremented by length. * *
In other words, an invocation of this method of the form * src.get(dst, off, len) has exactly the same effect as * the loop * *
* for (int i = off; i < off + len; i++) * dst[i] = src.get();* * except that it first checks that there are sufficient $type$s in * this buffer and it is potentially much more efficient. * * @param dst * The array into which $type$s are to be written * * @param offset * The offset within the array of the first $type$ to be * written; must be non-negative and no larger than * dst.length * * @param length * The maximum number of $type$s to be written to the given * array; must be non-negative and no larger than * dst.length - offset * * @return This buffer * * @throws BufferUnderflowException * If there are fewer than length $type$s * remaining in this buffer * * @throws IndexOutOfBoundsException * If the preconditions on the offset and length * parameters do not hold */ public $Type$Buffer get($type$[] dst, int offset, int length) { checkBounds(offset, length, dst.length); if (length > remaining()) throw new BufferUnderflowException(); int end = offset + length; for (int i = offset; i < end; i++) dst[i] = get(); return this; } /** * Relative bulk get method. * *
This method transfers $type$s from this buffer into the given * destination array. An invocation of this method of the form * src.get(a) behaves in exactly the same way as the invocation * *
* src.get(a, 0, a.length)* * @return This buffer * * @throws BufferUnderflowException * If there are fewer than length $type$s * remaining in this buffer */ public $Type$Buffer get($type$[] dst) { return get(dst, 0, dst.length); } // -- Bulk put operations -- /** * Relative bulk put method (optional operation). * *
This method transfers the $type$s remaining in the given source * buffer into this buffer. If there are more $type$s remaining in the * source buffer than in this buffer, that is, if * src.remaining() > remaining(), * then no $type$s are transferred and a {@link * BufferOverflowException} is thrown. * *
Otherwise, this method copies * n = src.remaining() $type$s from the given * buffer into this buffer, starting at each buffer's current position. * The positions of both buffers are then incremented by n. * *
In other words, an invocation of this method of the form * dst.put(src) has exactly the same effect as the loop * *
* while (src.hasRemaining()) * dst.put(src.get());* * except that it first checks that there is sufficient space in this * buffer and it is potentially much more efficient. * * @param src * The source buffer from which $type$s are to be read; * must not be this buffer * * @return This buffer * * @throws BufferOverflowException * If there is insufficient space in this buffer * for the remaining $type$s in the source buffer * * @throws IllegalArgumentException * If the source buffer is this buffer * * @throws ReadOnlyBufferException * If this buffer is read-only */ public $Type$Buffer put($Type$Buffer src) { if (src == this) throw new IllegalArgumentException(); if (isReadOnly()) throw new ReadOnlyBufferException(); int n = src.remaining(); if (n > remaining()) throw new BufferOverflowException(); for (int i = 0; i < n; i++) put(src.get()); return this; } /** * Relative bulk put method (optional operation). * *
This method transfers $type$s into this buffer from the given * source array. If there are more $type$s to be copied from the array * than remain in this buffer, that is, if * length > remaining(), then no * $type$s are transferred and a {@link BufferOverflowException} is * thrown. * *
Otherwise, this method copies length $type$s from the * given array into this buffer, starting at the given offset in the array * and at the current position of this buffer. The position of this buffer * is then incremented by length. * *
In other words, an invocation of this method of the form * dst.put(src, off, len) has exactly the same effect as * the loop * *
* for (int i = off; i < off + len; i++) * dst.put(a[i]);* * except that it first checks that there is sufficient space in this * buffer and it is potentially much more efficient. * * @param src * The array from which $type$s are to be read * * @param offset * The offset within the array of the first $type$ to be read; * must be non-negative and no larger than array.length * * @param length * The number of $type$s to be read from the given array; * must be non-negative and no larger than * array.length - offset * * @return This buffer * * @throws BufferOverflowException * If there is insufficient space in this buffer * * @throws IndexOutOfBoundsException * If the preconditions on the offset and length * parameters do not hold * * @throws ReadOnlyBufferException * If this buffer is read-only */ public $Type$Buffer put($type$[] src, int offset, int length) { checkBounds(offset, length, src.length); if (length > remaining()) throw new BufferOverflowException(); int end = offset + length; for (int i = offset; i < end; i++) this.put(src[i]); return this; } /** * Relative bulk put method (optional operation). * *
This method transfers the entire content of the given source * $type$ array into this buffer. An invocation of this method of the * form dst.put(a) behaves in exactly the same way as the * invocation * *
* dst.put(a, 0, a.length)* * @return This buffer * * @throws BufferOverflowException * If there is insufficient space in this buffer * * @throws ReadOnlyBufferException * If this buffer is read-only */ public final $Type$Buffer put($type$[] src) { return put(src, 0, src.length); } #if[char] /** * Relative bulk put method (optional operation). * *
This method transfers $type$s from the given string into this * buffer. If there are more $type$s to be copied from the string than * remain in this buffer, that is, if * end - start > remaining(), * then no $type$s are transferred and a {@link * BufferOverflowException} is thrown. * *
Otherwise, this method copies * n = end - start $type$s * from the given string into this buffer, starting at the given * start index and at the current position of this buffer. The * position of this buffer is then incremented by n. * *
In other words, an invocation of this method of the form * dst.put(src, start, end) has exactly the same effect * as the loop * *
* for (int i = start; i < end; i++) * dst.put(src.charAt(i));* * except that it first checks that there is sufficient space in this * buffer and it is potentially much more efficient. * * @param src * The string from which $type$s are to be read * * @param start * The offset within the string of the first $type$ to be read; * must be non-negative and no larger than * string.length() * * @param end * The offset within the string of the last $type$ to be read, * plus one; must be non-negative and no larger than * string.length() * * @return This buffer * * @throws BufferOverflowException * If there is insufficient space in this buffer * * @throws IndexOutOfBoundsException * If the preconditions on the start and end * parameters do not hold * * @throws ReadOnlyBufferException * If this buffer is read-only */ public $Type$Buffer put(String src, int start, int end) { checkBounds(start, end - start, src.length()); if (isReadOnly()) throw new ReadOnlyBufferException(); if (end - start > remaining()) throw new BufferOverflowException(); for (int i = start; i < end; i++) this.put(src.charAt(i)); return this; } /** * Relative bulk put method (optional operation). * *
This method transfers the entire content of the given source string * into this buffer. An invocation of this method of the form * dst.put(s) behaves in exactly the same way as the invocation * *
* dst.put(s, 0, s.length())* * @return This buffer * * @throws BufferOverflowException * If there is insufficient space in this buffer * * @throws ReadOnlyBufferException * If this buffer is read-only */ public final $Type$Buffer put(String src) { return put(src, 0, src.length()); } #end[char] // -- Other stuff -- /** * Tells whether or not this buffer is backed by an accessible $type$ * array. * *
If this method returns true then the {@link #array() array} * and {@link #arrayOffset() arrayOffset} methods may safely be invoked. *
* * @return true if, and only if, this buffer * is backed by an array and is not read-only */ public final boolean hasArray() { return (hb != null) && !isReadOnly; } /** * Returns the $type$ array that backs this * buffer (optional operation). * *Modifications to this buffer's content will cause the returned * array's content to be modified, and vice versa. * *
Invoke the {@link #hasArray hasArray} method before invoking this * method in order to ensure that this buffer has an accessible backing * array.
* * @return The array that backs this buffer * * @throws ReadOnlyBufferException * If this buffer is backed by an array but is read-only * * @throws UnsupportedOperationException * If this buffer is not backed by an accessible array */ public final $type$[] array() { if (hb == null) throw new UnsupportedOperationException(); if (isReadOnly) throw new ReadOnlyBufferException(); return hb; } /** * Returns the offset within this buffer's backing array of the first * element of the buffer (optional operation). * *If this buffer is backed by an array then buffer position p * corresponds to array index p + arrayOffset(). * *
Invoke the {@link #hasArray hasArray} method before invoking this * method in order to ensure that this buffer has an accessible backing * array.
* * @return The offset within this buffer's array * of the first element of the buffer * * @throws ReadOnlyBufferException * If this buffer is backed by an array but is read-only * * @throws UnsupportedOperationException * If this buffer is not backed by an accessible array */ public final int arrayOffset() { if (hb == null) throw new UnsupportedOperationException(); if (isReadOnly) throw new ReadOnlyBufferException(); return offset; } /** * Compacts this buffer (optional operation). * *The $type$s between the buffer's current position and its limit, * if any, are copied to the beginning of the buffer. That is, the * $type$ at index p = position() is copied * to index zero, the $type$ at index p + 1 is copied * to index one, and so forth until the $type$ at index * limit() - 1 is copied to index * n = limit() - 1 - p. * The buffer's position is then set to n+1 and its limit is set to * its capacity. The mark, if defined, is discarded. * *
The buffer's position is set to the number of $type$s copied, * rather than to zero, so that an invocation of this method can be * followed immediately by an invocation of another relative put * method.
* #if[byte] * *Invoke this method after writing data from a buffer in case the * write was incomplete. The following loop, for example, copies bytes * from one channel to another via the buffer buf: * *
* #end[byte] * * @return This buffer * * @throws ReadOnlyBufferException * If this buffer is read-only */ public abstract $Type$Buffer compact(); /** * Tells whether or not this $type$ buffer is direct. * * @return true if, and only if, this buffer is direct */ public abstract boolean isDirect(); #if[!char] /** * Returns a string summarizing the state of this buffer. * * @return A summary string */ public String toString() { StringBuffer sb = new StringBuffer(); sb.append(getClass().getName()); sb.append("[pos="); sb.append(position()); sb.append(" lim="); sb.append(limit()); sb.append(" cap="); sb.append(capacity()); sb.append("]"); return sb.toString(); } #end[!char] // ## Should really use unchecked accessors here for speed /** * Returns the current hash code of this buffer. * ** buf.clear(); // Prepare buffer for use * while (in.read(buf) >= 0 || buf.position != 0) { * buf.flip(); * out.write(buf); * buf.compact(); // In case of partial write * }
The hash code of a $type$ buffer depends only upon its remaining * elements; that is, upon the elements from position() up to, and * including, the element at limit() - 1. * *
Because buffer hash codes are content-dependent, it is inadvisable * to use buffers as keys in hash maps or similar data structures unless it * is known that their contents will not change.
* * @return The current hash code of this buffer */ public int hashCode() { int h = 1; int p = position(); for (int i = limit() - 1; i >= p; i--) #if[int] h = 31 * h + get(i); #else[int] h = 31 * h + (int)get(i); #end[int] return h; } /** * Tells whether or not this buffer is equal to another object. * *Two $type$ buffers are equal if, and only if, * *
They have the same element type,
They have the same number of remaining elements, and *
The two sequences of remaining elements, considered * independently of their starting positions, are pointwise equal. #if[floatingPointType] * This method considers two $type$ elements {@code a} and {@code b} * to be equal if * {@code (a == b) || ($Fulltype$.isNaN(a) && $Fulltype$.isNaN(b))}. * The values {@code -0.0} and {@code +0.0} are considered to be * equal, unlike {@link $Fulltype$#equals(Object)}. #end[floatingPointType] *
A $type$ buffer is not equal to any other type of object.
* * @param ob The object to which this buffer is to be compared * * @return true if, and only if, this buffer is equal to the * given object */ public boolean equals(Object ob) { if (this == ob) return true; if (!(ob instanceof $Type$Buffer)) return false; $Type$Buffer that = ($Type$Buffer)ob; if (this.remaining() != that.remaining()) return false; int p = this.position(); for (int i = this.limit() - 1, j = that.limit() - 1; i >= p; i--, j--) if (!equals(this.get(i), that.get(j))) return false; return true; } private static boolean equals($type$ x, $type$ y) { #if[floatingPointType] return (x == y) || ($Fulltype$.isNaN(x) && $Fulltype$.isNaN(y)); #else[floatingPointType] return x == y; #end[floatingPointType] } /** * Compares this buffer to another. * *Two $type$ buffers are compared by comparing their sequences of * remaining elements lexicographically, without regard to the starting * position of each sequence within its corresponding buffer. #if[floatingPointType] * Pairs of {@code $type$} elements are compared as if by invoking * {@link $Fulltype$#compare($type$,$type$)}, except that * {@code -0.0} and {@code 0.0} are considered to be equal. * {@code $Fulltype$.NaN} is considered by this method to be equal * to itself and greater than all other {@code $type$} values * (including {@code $Fulltype$.POSITIVE_INFINITY}). #else[floatingPointType] * Pairs of {@code $type$} elements are compared as if by invoking * {@link $Fulltype$#compare($type$,$type$)}. #end[floatingPointType] * *
A $type$ buffer is not comparable to any other type of object. * * @return A negative integer, zero, or a positive integer as this buffer * is less than, equal to, or greater than the given buffer */ public int compareTo($Type$Buffer that) { int n = this.position() + Math.min(this.remaining(), that.remaining()); for (int i = this.position(), j = that.position(); i < n; i++, j++) { int cmp = compare(this.get(i), that.get(j)); if (cmp != 0) return cmp; } return this.remaining() - that.remaining(); } private static int compare($type$ x, $type$ y) { #if[floatingPointType] return ((x < y) ? -1 : (x > y) ? +1 : (x == y) ? 0 : $Fulltype$.isNaN(x) ? ($Fulltype$.isNaN(y) ? 0 : +1) : -1); #else[floatingPointType] return $Fulltype$.compare(x, y); #end[floatingPointType] } // -- Other char stuff -- #if[char] /** * Returns a string containing the characters in this buffer. * *
The first character of the resulting string will be the character at * this buffer's position, while the last character will be the character * at index limit() - 1. Invoking this method does not * change the buffer's position.
* * @return The specified string */ public String toString() { return toString(position(), limit()); } abstract String toString(int start, int end); // package-private // --- Methods to support CharSequence --- /** * Returns the length of this character buffer. * *When viewed as a character sequence, the length of a character * buffer is simply the number of characters between the position * (inclusive) and the limit (exclusive); that is, it is equivalent to * remaining().
* * @return The length of this character buffer */ public final int length() { return remaining(); } /** * Reads the character at the given index relative to the current * position. * * @param index * The index of the character to be read, relative to the position; * must be non-negative and smaller than remaining() * * @return The character at index * position() + index * * @throws IndexOutOfBoundsException * If the preconditions on index do not hold */ public final char charAt(int index) { return get(position() + checkIndex(index, 1)); } /** * Creates a new character buffer that represents the specified subsequence * of this buffer, relative to the current position. * *The new buffer will share this buffer's content; that is, if the * content of this buffer is mutable then modifications to one buffer will * cause the other to be modified. The new buffer's capacity will be that * of this buffer, its position will be * position() + start, and its limit will be * position() + end. The new buffer will be * direct if, and only if, this buffer is direct, and it will be read-only * if, and only if, this buffer is read-only.
* * @param start * The index, relative to the current position, of the first * character in the subsequence; must be non-negative and no larger * than remaining() * * @param end * The index, relative to the current position, of the character * following the last character in the subsequence; must be no * smaller than start and no larger than * remaining() * * @return The new character buffer * * @throws IndexOutOfBoundsException * If the preconditions on start and end * do not hold */ public abstract CharBuffer subSequence(int start, int end); // --- Methods to support Appendable --- /** * Appends the specified character sequence to this * buffer (optional operation). * *An invocation of this method of the form dst.append(csq) * behaves in exactly the same way as the invocation * *
* dst.put(csq.toString())* *
Depending on the specification of toString for the * character sequence csq, the entire sequence may not be * appended. For instance, invoking the {@link $Type$Buffer#toString() * toString} method of a character buffer will return a subsequence whose * content depends upon the buffer's position and limit. * * @param csq * The character sequence to append. If csq is * null, then the four characters "null" are * appended to this character buffer. * * @return This buffer * * @throws BufferOverflowException * If there is insufficient space in this buffer * * @throws ReadOnlyBufferException * If this buffer is read-only * * @since 1.5 */ public $Type$Buffer append(CharSequence csq) { if (csq == null) return put("null"); else return put(csq.toString()); } /** * Appends a subsequence of the specified character sequence to this * buffer (optional operation). * *
An invocation of this method of the form dst.append(csq, start, * end) when csq is not null, behaves in exactly the * same way as the invocation * *
* dst.put(csq.subSequence(start, end).toString())* * @param csq * The character sequence from which a subsequence will be * appended. If csq is null, then characters * will be appended as if csq contained the four * characters "null". * * @return This buffer * * @throws BufferOverflowException * If there is insufficient space in this buffer * * @throws IndexOutOfBoundsException * If start or end are negative, start * is greater than end, or end is greater than * csq.length() * * @throws ReadOnlyBufferException * If this buffer is read-only * * @since 1.5 */ public $Type$Buffer append(CharSequence csq, int start, int end) { CharSequence cs = (csq == null ? "null" : csq); return put(cs.subSequence(start, end).toString()); } /** * Appends the specified $type$ to this * buffer (optional operation). * *
An invocation of this method of the form dst.append($x$) * behaves in exactly the same way as the invocation * *
* dst.put($x$)* * @param $x$ * The 16-bit $type$ to append * * @return This buffer * * @throws BufferOverflowException * If there is insufficient space in this buffer * * @throws ReadOnlyBufferException * If this buffer is read-only * * @since 1.5 */ public $Type$Buffer append($type$ $x$) { return put($x$); } #end[char] // -- Other byte stuff: Access to binary data -- #if[!byte] /** * Retrieves this buffer's byte order. * *
The byte order of $a$ $type$ buffer created by allocation or by
* wrapping an existing $type$ array is the {@link
* ByteOrder#nativeOrder native order} of the underlying
* hardware. The byte order of $a$ $type$ buffer created as a view of a byte buffer is that of the
* byte buffer at the moment that the view is created.
The byte order is used when reading or writing multibyte values, and * when creating buffers that are views of this byte buffer. The order of * a newly-created byte buffer is always {@link ByteOrder#BIG_ENDIAN * BIG_ENDIAN}.
* * @return This buffer's byte order */ public final ByteOrder order() { return bigEndian ? ByteOrder.BIG_ENDIAN : ByteOrder.LITTLE_ENDIAN; } /** * Modifies this buffer's byte order. * * @param bo * The new byte order, * either {@link ByteOrder#BIG_ENDIAN BIG_ENDIAN} * or {@link ByteOrder#LITTLE_ENDIAN LITTLE_ENDIAN} * * @return This buffer */ public final $Type$Buffer order(ByteOrder bo) { bigEndian = (bo == ByteOrder.BIG_ENDIAN); nativeByteOrder = (bigEndian == (Bits.byteOrder() == ByteOrder.BIG_ENDIAN)); return this; } // Unchecked accessors, for use by ByteBufferAs-X-Buffer classes // abstract byte _get(int i); // package-private abstract void _put(int i, byte b); // package-private // #BIN // // Binary-data access methods for short, char, int, long, float, // and double will be inserted here #end[byte] }