File	Doc	Category	Size	Date	Package
CharBuffer.java	API Doc	Java SE 5 API	41863	Fri Aug 26 16:47:48 BST 2005	java.nio

CharBuffer

• java.lang.Object
  • java.nio.Buffer

Fields Summary
final char[]	hb
final int	offset
boolean	isReadOnly

Constructors Summary
CharBuffer(int mark, int pos, int lim, int cap, char[] hb, int offset) super(mark, pos, lim, cap); this.hb = hb; this.offset = offset;
CharBuffer(int mark, int pos, int lim, int cap) // package-private this(mark, pos, lim, cap, null, 0);

Methods Summary
public static java.nio.CharBuffer	allocate(int capacity) Allocates a new character buffer. The new buffer's position will be zero, its limit will be its capacity, and its mark will be undefined. It will have a {@link #array backing array}, and its {@link #arrayOffset array offset} will be zero. param capacity The new buffer's capacity, in characters return The new character buffer throws IllegalArgumentException If the capacity is a negative integer if (capacity < 0) throw new IllegalArgumentException(); return new HeapCharBuffer(capacity, capacity);
public java.nio.CharBuffer	append(java.lang.CharSequence csq) 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 CharBuffer#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 if (csq == null) return put("null"); else return put(csq.toString());
public java.nio.CharBuffer	append(java.lang.CharSequence csq, int start, int end) 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 CharSequence cs = (csq == null ? "null" : csq); return put(cs.subSequence(start, end).toString());
public java.nio.CharBuffer	append(char c) Appends the specified character to this buffer  (optional operation). An invocation of this method of the form dst.append(c) behaves in exactly the same way as the invocation dst.put(c) param c The 16-bit character 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 return put(c);
public final char[]	array() Returns the character 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 if (hb == null) throw new UnsupportedOperationException(); if (isReadOnly) throw new ReadOnlyBufferException(); return hb;
public final int	arrayOffset() 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 if (hb == null) throw new UnsupportedOperationException(); if (isReadOnly) throw new ReadOnlyBufferException(); return offset;
public abstract java.nio.CharBuffer	asReadOnlyBuffer() Creates a new, read-only character 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 character buffer
public final char	charAt(int index) 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 return get(position() + checkIndex(index, 1));
public abstract java.nio.CharBuffer	compact() Compacts this buffer  (optional operation). The characters between the buffer's current position and its limit, if any, are copied to the beginning of the buffer. That is, the character at index p = position() is copied to index zero, the character at index p + 1 is copied to index one, and so forth until the character 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 characters copied, rather than to zero, so that an invocation of this method can be followed immediately by an invocation of another relative put method. return This buffer throws ReadOnlyBufferException If this buffer is read-only
public int	compareTo(java.nio.CharBuffer that) Compares this buffer to another. Two char buffers are compared by comparing their sequences of remaining elements lexicographically, without regard to the starting position of each sequence within its corresponding buffer. A char 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 int n = this.position() + Math.min(this.remaining(), that.remaining()); for (int i = this.position(), j = that.position(); i < n; i++, j++) { char v1 = this.get(i); char v2 = that.get(j); if (v1 == v2) continue; if ((v1 != v1) && (v2 != v2)) // For float and double continue; if (v1 < v2) return -1; return +1; } return this.remaining() - that.remaining();
public abstract java.nio.CharBuffer	duplicate() Creates a new character 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 character buffer
public boolean	equals(java.lang.Object ob) Tells whether or not this buffer is equal to another object. Two char 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. A char 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 if (!(ob instanceof CharBuffer)) return false; CharBuffer that = (CharBuffer)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--) { char v1 = this.get(i); char v2 = that.get(j); if (v1 != v2) { if ((v1 != v1) && (v2 != v2)) // For float and double continue; return false; } } return true;
public abstract char	get() Relative get method. Reads the character at this buffer's current position, and then increments the position. return The character at the buffer's current position throws BufferUnderflowException If the buffer's current position is not smaller than its limit
public abstract char	get(int index) Absolute get method. Reads the character at the given index. param index The index from which the character will be read return The character at the given index throws IndexOutOfBoundsException If index is negative or not smaller than the buffer's limit
public java.nio.CharBuffer	get(char[] dst, int offset, int length) Relative bulk get method. This method transfers characters from this buffer into the given destination array. If there are fewer characters remaining in the buffer than are required to satisfy the request, that is, if length > remaining(), then no characters are transferred and a {@link BufferUnderflowException} is thrown. Otherwise, this method copies length characters 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 characters in this buffer and it is potentially much more efficient. param dst The array into which characters are to be written param offset The offset within the array of the first character to be written; must be non-negative and no larger than dst.length param length The maximum number of characters 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 characters remaining in this buffer throws IndexOutOfBoundsException If the preconditions on the offset and length parameters do not hold 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;
public java.nio.CharBuffer	get(char[] dst) Relative bulk get method. This method transfers characters 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 characters remaining in this buffer return get(dst, 0, dst.length);
public final boolean	hasArray() Tells whether or not this buffer is backed by an accessible character 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 return (hb != null) && !isReadOnly;
public int	hashCode() Returns the current hash code of this buffer. The hash code of a char 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 int h = 1; int p = position(); for (int i = limit() - 1; i >= p; i--) h = 31 * h + (int)get(i); return h;
public abstract boolean	isDirect() Tells whether or not this character buffer is direct. return true if, and only if, this buffer is direct
public final int	length() 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 return remaining();
public abstract java.nio.ByteOrder	order() Retrieves this buffer's byte order. The byte order of a character buffer created by allocation or by wrapping an existing char array is the {@link ByteOrder#nativeOrder native order} of the underlying hardware. The byte order of a character buffer created as a view of a byte buffer is that of the byte buffer at the moment that the view is created. return This buffer's byte order
public abstract java.nio.CharBuffer	put(char c) Relative put method  (optional operation). Writes the given character into this buffer at the current position, and then increments the position. param c The character 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 java.nio.CharBuffer	put(int index, char c) Absolute put method  (optional operation). Writes the given character into this buffer at the given index. param index The index at which the character will be written param c The character 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 java.nio.CharBuffer	put(java.nio.CharBuffer src) Relative bulk put method  (optional operation). This method transfers the characters remaining in the given source buffer into this buffer. If there are more characters remaining in the source buffer than in this buffer, that is, if src.remaining() > remaining(), then no characters are transferred and a {@link BufferOverflowException} is thrown. Otherwise, this method copies n = src.remaining() characters 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 characters 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 characters in the source buffer throws IllegalArgumentException If the source buffer is this buffer throws ReadOnlyBufferException If this buffer is read-only if (src == this) throw new IllegalArgumentException(); int n = src.remaining(); if (n > remaining()) throw new BufferOverflowException(); for (int i = 0; i < n; i++) put(src.get()); return this;
public java.nio.CharBuffer	put(char[] src, int offset, int length) Relative bulk put method  (optional operation). This method transfers characters into this buffer from the given source array. If there are more characters to be copied from the array than remain in this buffer, that is, if length > remaining(), then no characters are transferred and a {@link BufferOverflowException} is thrown. Otherwise, this method copies length characters 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 characters are to be read param offset The offset within the array of the first character to be read; must be non-negative and no larger than array.length param length The number of characters 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 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;
public final java.nio.CharBuffer	put(char[] src) Relative bulk put method  (optional operation). This method transfers the entire content of the given source character 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 return put(src, 0, src.length);
public java.nio.CharBuffer	put(java.lang.String src, int start, int end) Relative bulk put method  (optional operation). This method transfers characters from the given string into this buffer. If there are more characters to be copied from the string than remain in this buffer, that is, if end - start > remaining(), then no characters are transferred and a {@link BufferOverflowException} is thrown. Otherwise, this method copies n = end - start characters 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 characters are to be read param start The offset within the string of the first character to be read; must be non-negative and no larger than string.length() param end The offset within the string of the last character 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 checkBounds(start, end - start, src.length()); for (int i = start; i < end; i++) this.put(src.charAt(i)); return this;
public final java.nio.CharBuffer	put(java.lang.String src) 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 return put(src, 0, src.length());
public int	read(java.nio.CharBuffer target) Attempts to read characters into the specified character buffer. The buffer is used as a repository of characters as-is: the only changes made are the results of a put operation. No flipping or rewinding of the buffer is performed. param target the buffer to read characters into return The number of characters added to the buffer, or -1 if this source of characters is at its end throws IOException if an I/O error occurs throws NullPointerException if target is null throws ReadOnlyBufferException if target is a read only buffer // Determine the number of bytes n that can be transferred int targetRemaining = target.remaining(); int remaining = remaining(); if (remaining == 0) return -1; int n = Math.min(remaining, targetRemaining); int limit = limit(); // Set source limit to prevent target overflow if (targetRemaining < remaining) limit(position() + n); try { if (n > 0) target.put(this); } finally { limit(limit); // restore real limit } return n;
public abstract java.nio.CharBuffer	slice() Creates a new character 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 characters 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 character buffer
public abstract java.lang.CharSequence	subSequence(int start, int end) 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 java.lang.String	toString() 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 return toString(position(), limit());
abstract java.lang.String	toString(int start, int end)
public static java.nio.CharBuffer	wrap(char[] array, int offset, int length) Wraps a character array into a buffer. The new buffer will be backed by the given character 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 backing array} will be the given array, and its {@link #arrayOffset array offset} will be zero. param array The array that will back the new buffer param offset The offset of the subarray to be used; must be non-negative and no larger than array.length. The new buffer's position will be set to this value. param length The length of the subarray to be used; must be non-negative and no larger than array.length - offset. The new buffer's limit will be set to offset + length. return The new character buffer throws IndexOutOfBoundsException If the preconditions on the offset and length parameters do not hold try { return new HeapCharBuffer(array, offset, length); } catch (IllegalArgumentException x) { throw new IndexOutOfBoundsException(); }
public static java.nio.CharBuffer	wrap(char[] array) Wraps a character array into a buffer. The new buffer will be backed by the given character 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. param array The array that will back this buffer return The new character buffer return wrap(array, 0, array.length);
public static java.nio.CharBuffer	wrap(java.lang.CharSequence csq, int start, int end) 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 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 try { return new StringCharBuffer(csq, start, end); } catch (IllegalArgumentException x) { throw new IndexOutOfBoundsException(); }
public static java.nio.CharBuffer	wrap(java.lang.CharSequence csq) Wraps a string into a buffer. The content of the new, read-only buffer will be the content of the given string. 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 return wrap(csq, 0, csq.length());