/* * Copyright 2008 Google Inc. * * Licensed under the Apache License, Version 2.0 (the "License"); you may not * use this file except in compliance with the License. You may obtain a copy of * the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the * License for the specific language governing permissions and limitations under * the License. */ package java.lang; import com.google.gwt.core.client.GWT; import com.google.gwt.core.client.impl.StringBufferImpl; /** * A fast way to create strings using multiple appends. This is implemented * using a {@link StringBufferImpl} that is chosen with deferred binding. * * Most methods will give expected performance results. Exceptions are * {@link #setCharAt(int, char)}, which is O(n), and {@link #length()}, which * forces a {@link #toString()} and thus should not be used many times on the * same <code>StringBuffer</code>. * * This class is an exact clone of {@link StringBuilder} except for the name. * Any change made to one should be mirrored in the other. */ public class StringBuffer implements CharSequence, Appendable { private final StringBufferImpl impl = GWT.create(StringBufferImpl.class); private final Object data = impl.createData(); public StringBuffer() { } public StringBuffer(CharSequence s) { this(s.toString()); } /** * This implementation does not track capacity; using this constructor is * functionally equivalent to using the zero-argument constructor. */ @SuppressWarnings("unused") public StringBuffer(int ignoredCapacity) { } public StringBuffer(String s) { append(s); } public StringBuffer append(boolean x) { impl.append(data, x); return this; } public StringBuffer append(char x) { impl.appendNonNull(data, String.valueOf(x)); return this; } public StringBuffer append(char[] x) { impl.appendNonNull(data, String.valueOf(x)); return this; } public StringBuffer append(char[] x, int start, int len) { impl.appendNonNull(data, String.valueOf(x, start, len)); return this; } public StringBuffer append(CharSequence x) { impl.append(data, x); return this; } public StringBuffer append(CharSequence x, int start, int end) { if (x == null) { x = "null"; } impl.append(data, x.subSequence(start, end)); return this; } public StringBuffer append(double x) { impl.append(data, x); return this; } public StringBuffer append(float x) { impl.append(data, x); return this; } public StringBuffer append(int x) { impl.append(data, x); return this; } public StringBuffer append(long x) { impl.appendNonNull(data, String.valueOf(x)); return this; } public StringBuffer append(Object x) { impl.append(data, x); return this; } public StringBuffer append(String x) { impl.append(data, x); return this; } public StringBuffer append(StringBuffer x) { impl.append(data, x); return this; } /** * This implementation does not track capacity; always returns * {@link Integer#MAX_VALUE}. */ public int capacity() { return Integer.MAX_VALUE; } public char charAt(int index) { return toString().charAt(index); } public StringBuffer delete(int start, int end) { return replace(start, end, ""); } public StringBuffer deleteCharAt(int start) { return delete(start, start + 1); } /** * This implementation does not track capacity; calling this method has no * effect. */ @SuppressWarnings("unused") public void ensureCapacity(int ignoredCapacity) { } public void getChars(int srcStart, int srcEnd, char[] dst, int dstStart) { String.__checkBounds(length(), srcStart, srcEnd); String.__checkBounds(dst.length, dstStart, dstStart + (srcEnd - srcStart)); String s = toString(); while (srcStart < srcEnd) { dst[dstStart++] = s.charAt(srcStart++); } } public int indexOf(String x) { return toString().indexOf(x); } public int indexOf(String x, int start) { return toString().indexOf(x, start); } public StringBuffer insert(int index, boolean x) { return insert(index, String.valueOf(x)); } public StringBuffer insert(int index, char x) { return insert(index, String.valueOf(x)); } public StringBuffer insert(int index, char[] x) { return insert(index, String.valueOf(x)); } public StringBuffer insert(int index, char[] x, int offset, int len) { return insert(index, String.valueOf(x, offset, len)); } public StringBuffer insert(int index, CharSequence chars) { return insert(index, chars.toString()); } public StringBuffer insert(int index, CharSequence chars, int start, int end) { return insert(index, chars.subSequence(start, end).toString()); } public StringBuffer insert(int index, double x) { return insert(index, String.valueOf(x)); } public StringBuffer insert(int index, float x) { return insert(index, String.valueOf(x)); } public StringBuffer insert(int index, int x) { return insert(index, String.valueOf(x)); } public StringBuffer insert(int index, long x) { return insert(index, String.valueOf(x)); } public StringBuffer insert(int index, Object x) { return insert(index, String.valueOf(x)); } public StringBuffer insert(int index, String x) { return replace(index, index, x); } public int lastIndexOf(String s) { return toString().lastIndexOf(s); } public int lastIndexOf(String s, int start) { return toString().lastIndexOf(s, start); } public int length() { return impl.length(data); } public StringBuffer replace(int start, int end, String toInsert) { impl.replace(data, start, end, toInsert); return this; } /** * Warning! This method is <b>much</b> slower than the JRE implementation. If * you need to do character level manipulation, you are strongly advised to * use a char[] directly. */ public void setCharAt(int index, char x) { replace(index, index + 1, String.valueOf(x)); } public void setLength(int newLength) { int oldLength = length(); if (newLength < oldLength) { delete(newLength, oldLength); } else if (newLength > oldLength) { append(new char[newLength - oldLength]); } } public CharSequence subSequence(int start, int end) { return this.substring(start, end); } public String substring(int begin) { return toString().substring(begin); } public String substring(int begin, int end) { return toString().substring(begin, end); } @Override public String toString() { return impl.toString(data); } public void trimToSize() { } }