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Diffstat (limited to 'libjava/java/lang/StringBuilder.java')
| -rw-r--r-- | libjava/java/lang/StringBuilder.java | 706 |
1 files changed, 706 insertions, 0 deletions
diff --git a/libjava/java/lang/StringBuilder.java b/libjava/java/lang/StringBuilder.java new file mode 100644 index 000000000..aefe9272b --- /dev/null +++ b/libjava/java/lang/StringBuilder.java @@ -0,0 +1,706 @@ +/* StringBuilder.java -- Unsynchronized growable strings + Copyright (C) 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2008 + Free Software Foundation, Inc. + +This file is part of GNU Classpath. + +GNU Classpath is free software; you can redistribute it and/or modify +it under the terms of the GNU General Public License as published by +the Free Software Foundation; either version 2, or (at your option) +any later version. + +GNU Classpath 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 for more details. + +You should have received a copy of the GNU General Public License +along with GNU Classpath; see the file COPYING. If not, write to the +Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA +02110-1301 USA. + +Linking this library statically or dynamically with other modules is +making a combined work based on this library. Thus, the terms and +conditions of the GNU General Public License cover the whole +combination. + +As a special exception, the copyright holders of this library give you +permission to link this library with independent modules to produce an +executable, regardless of the license terms of these independent +modules, and to copy and distribute the resulting executable under +terms of your choice, provided that you also meet, for each linked +independent module, the terms and conditions of the license of that +module. An independent module is a module which is not derived from +or based on this library. If you modify this library, you may extend +this exception to your version of the library, but you are not +obligated to do so. If you do not wish to do so, delete this +exception statement from your version. */ + +package java.lang; + +import java.io.Serializable; + +/** + * <code>StringBuilder</code> represents a changeable <code>String</code>. + * It provides the operations required to modify the + * <code>StringBuilder</code>, including insert, replace, delete, append, + * and reverse. It like <code>StringBuffer</code>, but is not + * synchronized. It is ideal for use when it is known that the + * object will only be used from a single thread. + * + * <p><code>StringBuilder</code>s are variable-length in nature, so even if + * you initialize them to a certain size, they can still grow larger than + * that. <em>Capacity</em> indicates the number of characters the + * <code>StringBuilder</code> can have in it before it has to grow (growing + * the char array is an expensive operation involving <code>new</code>). + * + * <p>Incidentally, compilers often implement the String operator "+" + * by using a <code>StringBuilder</code> operation:<br> + * <code>a + b</code><br> + * is the same as<br> + * <code>new StringBuilder().append(a).append(b).toString()</code>. + * + * <p>Classpath's StringBuilder is capable of sharing memory with Strings for + * efficiency. This will help when a StringBuilder is converted to a String + * and the StringBuilder is not changed after that (quite common when + * performing string concatenation). + * + * @author Paul Fisher + * @author John Keiser + * @author Tom Tromey + * @author Eric Blake (ebb9@email.byu.edu) + * @see String + * @see StringBuffer + * + * @since 1.5 + */ +public final class StringBuilder + extends AbstractStringBuffer + implements Serializable, CharSequence, Appendable +{ + // Implementation note: if you change this class, you usually will + // want to change StringBuffer as well. + + /** + * For compatability with Sun's JDK + */ + private static final long serialVersionUID = 4383685877147921099L; + + /** + * Create a new StringBuilder with default capacity 16. + */ + public StringBuilder() + { + super(); + } + + /** + * Create an empty <code>StringBuilder</code> with the specified initial + * capacity. + * + * @param capacity the initial capacity + * @throws NegativeArraySizeException if capacity is negative + */ + public StringBuilder(int capacity) + { + super(capacity); + } + + /** + * Create a new <code>StringBuilder</code> with the characters in the + * specified <code>String</code>. Initial capacity will be the size of the + * String plus 16. + * + * @param str the <code>String</code> to convert + * @throws NullPointerException if str is null + */ + public StringBuilder(String str) + { + super(str); + } + + /** + * Create a new <code>StringBuilder</code> with the characters in the + * specified <code>CharSequence</code>. Initial capacity will be the + * length of the sequence plus 16; if the sequence reports a length + * less than or equal to 0, then the initial capacity will be 16. + * + * @param seq the initializing <code>CharSequence</code> + * @throws NullPointerException if str is null + */ + public StringBuilder(CharSequence seq) + { + super(seq); + } + + /** + * Get the length of the <code>String</code> this <code>StringBuilder</code> + * would create. Not to be confused with the <em>capacity</em> of the + * <code>StringBuilder</code>. + * + * @return the length of this <code>StringBuilder</code> + * @see #capacity() + * @see #setLength(int) + */ + public int length() + { + return count; + } + + /** + * Get the total number of characters this <code>StringBuilder</code> can + * support before it must be grown. Not to be confused with <em>length</em>. + * + * @return the capacity of this <code>StringBuilder</code> + * @see #length() + * @see #ensureCapacity(int) + */ + public int capacity() + { + return value.length; + } + + /** + * Append the <code>String</code> value of the argument to this + * <code>StringBuilder</code>. Uses <code>String.valueOf()</code> to convert + * to <code>String</code>. + * + * @param obj the <code>Object</code> to convert and append + * @return this <code>StringBuilder</code> + * @see String#valueOf(Object) + * @see #append(String) + */ + public StringBuilder append(Object obj) + { + super.append(obj); + return this; + } + + /** + * Append the <code>String</code> to this <code>StringBuilder</code>. If + * str is null, the String "null" is appended. + * + * @param str the <code>String</code> to append + * @return this <code>StringBuilder</code> + */ + public StringBuilder append(String str) + { + super.append(str); + return this; + } + + /** + * Append the <code>StringBuilder</code> value of the argument to this + * <code>StringBuilder</code>. This behaves the same as + * <code>append((Object) stringBuffer)</code>, except it is more efficient. + * + * @param stringBuffer the <code>StringBuilder</code> to convert and append + * @return this <code>StringBuilder</code> + * @see #append(Object) + */ + public StringBuilder append(StringBuffer stringBuffer) + { + super.append(stringBuffer); + return this; + } + + /** + * Append the <code>char</code> array to this <code>StringBuilder</code>. + * This is similar (but more efficient) than + * <code>append(new String(data))</code>, except in the case of null. + * + * @param data the <code>char[]</code> to append + * @return this <code>StringBuilder</code> + * @throws NullPointerException if <code>str</code> is <code>null</code> + * @see #append(char[], int, int) + */ + public StringBuilder append(char[] data) + { + super.append(data, 0, data.length); + return this; + } + + /** + * Append part of the <code>char</code> array to this + * <code>StringBuilder</code>. This is similar (but more efficient) than + * <code>append(new String(data, offset, count))</code>, except in the case + * of null. + * + * @param data the <code>char[]</code> to append + * @param offset the start location in <code>str</code> + * @param count the number of characters to get from <code>str</code> + * @return this <code>StringBuilder</code> + * @throws NullPointerException if <code>str</code> is <code>null</code> + * @throws IndexOutOfBoundsException if offset or count is out of range + * (while unspecified, this is a StringIndexOutOfBoundsException) + */ + public StringBuilder append(char[] data, int offset, int count) + { + super.append(data, offset, count); + return this; + } + + /** + * Append the <code>String</code> value of the argument to this + * <code>StringBuilder</code>. Uses <code>String.valueOf()</code> to convert + * to <code>String</code>. + * + * @param bool the <code>boolean</code> to convert and append + * @return this <code>StringBuilder</code> + * @see String#valueOf(boolean) + */ + public StringBuilder append(boolean bool) + { + super.append(bool); + return this; + } + + /** + * Append the <code>char</code> to this <code>StringBuilder</code>. + * + * @param ch the <code>char</code> to append + * @return this <code>StringBuilder</code> + */ + public StringBuilder append(char ch) + { + super.append(ch); + return this; + } + + /** + * Append the characters in the <code>CharSequence</code> to this + * buffer. + * + * @param seq the <code>CharSequence</code> providing the characters + * @return this <code>StringBuilder</code> + */ + public StringBuilder append(CharSequence seq) + { + super.append(seq, 0, seq.length()); + return this; + } + + /** + * Append some characters from the <code>CharSequence</code> to this + * buffer. If the argument is null, the four characters "null" are + * appended. + * + * @param seq the <code>CharSequence</code> providing the characters + * @param start the starting index + * @param end one past the final index + * @return this <code>StringBuilder</code> + */ + public StringBuilder append(CharSequence seq, int start, + int end) + { + super.append(seq, start, end); + return this; + } + + /** + * Append the <code>String</code> value of the argument to this + * <code>StringBuilder</code>. Uses <code>String.valueOf()</code> to convert + * to <code>String</code>. + * + * @param inum the <code>int</code> to convert and append + * @return this <code>StringBuilder</code> + * @see String#valueOf(int) + */ + // This is native in libgcj, for efficiency. + public StringBuilder append(int inum) + { + super.append(inum); + return this; + } + + /** + * Append the <code>String</code> value of the argument to this + * <code>StringBuilder</code>. Uses <code>String.valueOf()</code> to convert + * to <code>String</code>. + * + * @param lnum the <code>long</code> to convert and append + * @return this <code>StringBuilder</code> + * @see String#valueOf(long) + */ + public StringBuilder append(long lnum) + { + super.append(lnum); + return this; + } + + /** + * Append the <code>String</code> value of the argument to this + * <code>StringBuilder</code>. Uses <code>String.valueOf()</code> to convert + * to <code>String</code>. + * + * @param fnum the <code>float</code> to convert and append + * @return this <code>StringBuilder</code> + * @see String#valueOf(float) + */ + public StringBuilder append(float fnum) + { + super.append(fnum); + return this; + } + + /** + * Append the <code>String</code> value of the argument to this + * <code>StringBuilder</code>. Uses <code>String.valueOf()</code> to convert + * to <code>String</code>. + * + * @param dnum the <code>double</code> to convert and append + * @return this <code>StringBuilder</code> + * @see String#valueOf(double) + */ + public StringBuilder append(double dnum) + { + super.append(dnum); + return this; + } + + /** + * Append the code point to this <code>StringBuilder</code>. + * This is like #append(char), but will append two characters + * if a supplementary code point is given. + * + * @param code the code point to append + * @return this <code>StringBuilder</code> + * @see Character#toChars(int, char[], int) + * @since 1.5 + */ + public StringBuilder appendCodePoint(int code) + { + super.appendCodePoint(code); + return this; + } + + /** + * Delete characters from this <code>StringBuilder</code>. + * <code>delete(10, 12)</code> will delete 10 and 11, but not 12. It is + * harmless for end to be larger than length(). + * + * @param start the first character to delete + * @param end the index after the last character to delete + * @return this <code>StringBuilder</code> + * @throws StringIndexOutOfBoundsException if start or end are out of bounds + */ + public StringBuilder delete(int start, int end) + { + super.delete(start, end); + return this; + } + + /** + * Delete a character from this <code>StringBuilder</code>. + * + * @param index the index of the character to delete + * @return this <code>StringBuilder</code> + * @throws StringIndexOutOfBoundsException if index is out of bounds + */ + public StringBuilder deleteCharAt(int index) + { + super.deleteCharAt(index); + return this; + } + + /** + * Replace characters between index <code>start</code> (inclusive) and + * <code>end</code> (exclusive) with <code>str</code>. If <code>end</code> + * is larger than the size of this StringBuilder, all characters after + * <code>start</code> are replaced. + * + * @param start the beginning index of characters to delete (inclusive) + * @param end the ending index of characters to delete (exclusive) + * @param str the new <code>String</code> to insert + * @return this <code>StringBuilder</code> + * @throws StringIndexOutOfBoundsException if start or end are out of bounds + * @throws NullPointerException if str is null + */ + public StringBuilder replace(int start, int end, String str) + { + super.replace(start, end, str); + return this; + } + + /** + * Creates a substring of this StringBuilder, starting at a specified index + * and ending at the end of this StringBuilder. + * + * @param beginIndex index to start substring (base 0) + * @return new String which is a substring of this StringBuilder + * @throws StringIndexOutOfBoundsException if beginIndex is out of bounds + * @see #substring(int, int) + */ + public String substring(int beginIndex) + { + return substring(beginIndex, count); + } + + /** + * Creates a substring of this StringBuilder, starting at a specified index + * and ending at one character before a specified index. This is implemented + * the same as <code>substring(beginIndex, endIndex)</code>, to satisfy + * the CharSequence interface. + * + * @param beginIndex index to start at (inclusive, base 0) + * @param endIndex index to end at (exclusive) + * @return new String which is a substring of this StringBuilder + * @throws IndexOutOfBoundsException if beginIndex or endIndex is out of + * bounds + * @see #substring(int, int) + */ + public CharSequence subSequence(int beginIndex, int endIndex) + { + return substring(beginIndex, endIndex); + } + + /** + * Creates a substring of this StringBuilder, starting at a specified index + * and ending at one character before a specified index. + * + * @param beginIndex index to start at (inclusive, base 0) + * @param endIndex index to end at (exclusive) + * @return new String which is a substring of this StringBuilder + * @throws StringIndexOutOfBoundsException if beginIndex or endIndex is out + * of bounds + */ + public String substring(int beginIndex, int endIndex) + { + int len = endIndex - beginIndex; + if (beginIndex < 0 || endIndex > count || endIndex < beginIndex) + throw new StringIndexOutOfBoundsException(); + if (len == 0) + return ""; + return new String(value, beginIndex, len); + } + + /** + * Insert a subarray of the <code>char[]</code> argument into this + * <code>StringBuilder</code>. + * + * @param offset the place to insert in this buffer + * @param str the <code>char[]</code> to insert + * @param str_offset the index in <code>str</code> to start inserting from + * @param len the number of characters to insert + * @return this <code>StringBuilder</code> + * @throws NullPointerException if <code>str</code> is <code>null</code> + * @throws StringIndexOutOfBoundsException if any index is out of bounds + */ + public StringBuilder insert(int offset, + char[] str, int str_offset, int len) + { + super.insert(offset, str, str_offset, len); + return this; + } + + /** + * Insert the <code>String</code> value of the argument into this + * <code>StringBuilder</code>. Uses <code>String.valueOf()</code> to convert + * to <code>String</code>. + * + * @param offset the place to insert in this buffer + * @param obj the <code>Object</code> to convert and insert + * @return this <code>StringBuilder</code> + * @exception StringIndexOutOfBoundsException if offset is out of bounds + * @see String#valueOf(Object) + */ + public StringBuilder insert(int offset, Object obj) + { + super.insert(offset, obj); + return this; + } + + /** + * Insert the <code>String</code> argument into this + * <code>StringBuilder</code>. If str is null, the String "null" is used + * instead. + * + * @param offset the place to insert in this buffer + * @param str the <code>String</code> to insert + * @return this <code>StringBuilder</code> + * @throws StringIndexOutOfBoundsException if offset is out of bounds + */ + public StringBuilder insert(int offset, String str) + { + super.insert(offset, str); + return this; + } + + /** + * Insert the <code>CharSequence</code> argument into this + * <code>StringBuilder</code>. If the sequence is null, the String + * "null" is used instead. + * + * @param offset the place to insert in this buffer + * @param sequence the <code>CharSequence</code> to insert + * @return this <code>StringBuilder</code> + * @throws IndexOutOfBoundsException if offset is out of bounds + */ + public StringBuilder insert(int offset, CharSequence sequence) + { + super.insert(offset, sequence); + return this; + } + + /** + * Insert a subsequence of the <code>CharSequence</code> argument into this + * <code>StringBuilder</code>. If the sequence is null, the String + * "null" is used instead. + * + * @param offset the place to insert in this buffer + * @param sequence the <code>CharSequence</code> to insert + * @param start the starting index of the subsequence + * @param end one past the ending index of the subsequence + * @return this <code>StringBuilder</code> + * @throws IndexOutOfBoundsException if offset, start, + * or end are out of bounds + */ + public StringBuilder insert(int offset, CharSequence sequence, + int start, int end) + { + super.insert(offset, sequence, start, end); + return this; + } + + /** + * Insert the <code>char[]</code> argument into this + * <code>StringBuilder</code>. + * + * @param offset the place to insert in this buffer + * @param data the <code>char[]</code> to insert + * @return this <code>StringBuilder</code> + * @throws NullPointerException if <code>data</code> is <code>null</code> + * @throws StringIndexOutOfBoundsException if offset is out of bounds + * @see #insert(int, char[], int, int) + */ + public StringBuilder insert(int offset, char[] data) + { + super.insert(offset, data); + return this; + } + + /** + * Insert the <code>String</code> value of the argument into this + * <code>StringBuilder</code>. Uses <code>String.valueOf()</code> to convert + * to <code>String</code>. + * + * @param offset the place to insert in this buffer + * @param bool the <code>boolean</code> to convert and insert + * @return this <code>StringBuilder</code> + * @throws StringIndexOutOfBoundsException if offset is out of bounds + * @see String#valueOf(boolean) + */ + public StringBuilder insert(int offset, boolean bool) + { + super.insert(offset, bool); + return this; + } + + /** + * Insert the <code>char</code> argument into this <code>StringBuilder</code>. + * + * @param offset the place to insert in this buffer + * @param ch the <code>char</code> to insert + * @return this <code>StringBuilder</code> + * @throws StringIndexOutOfBoundsException if offset is out of bounds + */ + public StringBuilder insert(int offset, char ch) + { + super.insert(offset, ch); + return this; + } + + /** + * Insert the <code>String</code> value of the argument into this + * <code>StringBuilder</code>. Uses <code>String.valueOf()</code> to convert + * to <code>String</code>. + * + * @param offset the place to insert in this buffer + * @param inum the <code>int</code> to convert and insert + * @return this <code>StringBuilder</code> + * @throws StringIndexOutOfBoundsException if offset is out of bounds + * @see String#valueOf(int) + */ + public StringBuilder insert(int offset, int inum) + { + super.insert(offset, inum); + return this; + } + + /** + * Insert the <code>String</code> value of the argument into this + * <code>StringBuilder</code>. Uses <code>String.valueOf()</code> to convert + * to <code>String</code>. + * + * @param offset the place to insert in this buffer + * @param lnum the <code>long</code> to convert and insert + * @return this <code>StringBuilder</code> + * @throws StringIndexOutOfBoundsException if offset is out of bounds + * @see String#valueOf(long) + */ + public StringBuilder insert(int offset, long lnum) + { + super.insert(offset, lnum); + return this; + } + + /** + * Insert the <code>String</code> value of the argument into this + * <code>StringBuilder</code>. Uses <code>String.valueOf()</code> to convert + * to <code>String</code>. + * + * @param offset the place to insert in this buffer + * @param fnum the <code>float</code> to convert and insert + * @return this <code>StringBuilder</code> + * @throws StringIndexOutOfBoundsException if offset is out of bounds + * @see String#valueOf(float) + */ + public StringBuilder insert(int offset, float fnum) + { + super.insert(offset, fnum); + return this; + } + + /** + * Insert the <code>String</code> value of the argument into this + * <code>StringBuilder</code>. Uses <code>String.valueOf()</code> to convert + * to <code>String</code>. + * + * @param offset the place to insert in this buffer + * @param dnum the <code>double</code> to convert and insert + * @return this <code>StringBuilder</code> + * @throws StringIndexOutOfBoundsException if offset is out of bounds + * @see String#valueOf(double) + */ + public StringBuilder insert(int offset, double dnum) + { + super.insert(offset, dnum); + return this; + } + + /** + * Reverse the characters in this StringBuilder. The same sequence of + * characters exists, but in the reverse index ordering. + * + * @return this <code>StringBuilder</code> + */ + public StringBuilder reverse() + { + super.reverse(); + return this; + } + + /** + * Convert this <code>StringBuilder</code> to a <code>String</code>. The + * String is composed of the characters currently in this StringBuilder. Note + * that the result is a copy, and that future modifications to this buffer + * do not affect the String. + * + * @return the characters in this StringBuilder + */ + public String toString() + { + return new String(this); + } + +} |