001 /*
002 * $Id: GString.java,v 1.12 2004/05/04 02:54:44 spullara Exp $
003 *
004 * Copyright 2003 (C) James Strachan and Bob Mcwhirter. All Rights Reserved.
005 *
006 * Redistribution and use of this software and associated documentation
007 * ("Software"), with or without modification, are permitted provided that the
008 * following conditions are met: 1. Redistributions of source code must retain
009 * copyright statements and notices. Redistributions must also contain a copy
010 * of this document. 2. Redistributions in binary form must reproduce the above
011 * copyright notice, this list of conditions and the following disclaimer in
012 * the documentation and/or other materials provided with the distribution. 3.
013 * The name "groovy" must not be used to endorse or promote products derived
014 * from this Software without prior written permission of The Codehaus. For
015 * written permission, please contact info@codehaus.org. 4. Products derived
016 * from this Software may not be called "groovy" nor may "groovy" appear in
017 * their names without prior written permission of The Codehaus. "groovy" is a
018 * registered trademark of The Codehaus. 5. Due credit should be given to The
019 * Codehaus - http://groovy.codehaus.org/
020 *
021 * THIS SOFTWARE IS PROVIDED BY THE CODEHAUS AND CONTRIBUTORS ``AS IS'' AND ANY
022 * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
023 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
024 * DISCLAIMED. IN NO EVENT SHALL THE CODEHAUS OR ITS CONTRIBUTORS BE LIABLE FOR
025 * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
026 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
027 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
028 * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
029 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
030 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
031 * DAMAGE.
032 *
033 */
034 package groovy.lang;
035
036 import java.io.IOException;
037 import java.io.StringWriter;
038 import java.io.Writer;
039 import java.util.ArrayList;
040 import java.util.Arrays;
041 import java.util.List;
042
043 import org.codehaus.groovy.runtime.InvokerHelper;
044
045 /**
046 * Represents a String which contains embedded values such as "hello there
047 * ${user} how are you?" which can be evaluated lazily. Advanced users can
048 * iterate over the text and values to perform special processing, such as for
049 * performing SQL operations, the values can be substituted for ? and the
050 * actual value objects can be bound to a JDBC statement. The lovely name of
051 * this class was suggested by Jules Gosnell and was such a good idea, I
052 * couldn't resist :)
053 *
054 * @author <a href="mailto:james@coredevelopers.net">James Strachan</a>
055 * @version $Revision: 1.12 $
056 */
057 public abstract class GString extends GroovyObjectSupport implements Comparable, CharSequence, Writable {
058
059 private Object[] values;
060
061 public GString(Object values) {
062 this.values = (Object[]) values;
063 }
064
065 public GString(Object[] values) {
066 this.values = values;
067 }
068
069 // will be static in an instance
070 public abstract String[] getStrings();
071
072 /**
073 * Overloaded to implement duck typing for Strings
074 * so that any method that can't be evaluated on this
075 * object will be forwarded to the toString() object instead.
076 */
077 public Object invokeMethod(String name, Object args) {
078 try {
079 return super.invokeMethod(name, args);
080 }
081 catch (MissingMethodException e) {
082 // lets try invoke the method on the real String
083 return InvokerHelper.invokeMethod(toString(), name, args);
084 }
085 }
086
087 public Object[] getValues() {
088 return values;
089 }
090
091 public GString plus(GString that) {
092 List stringList = new ArrayList();
093 List valueList = new ArrayList();
094
095 stringList.addAll(Arrays.asList(getStrings()));
096 valueList.addAll(Arrays.asList(getValues()));
097
098 if (stringList.size() > valueList.size()) {
099 valueList.add("");
100 }
101
102 stringList.addAll(Arrays.asList(that.getStrings()));
103 valueList.addAll(Arrays.asList(that.getValues()));
104
105 final String[] newStrings = new String[stringList.size()];
106 stringList.toArray(newStrings);
107 Object[] newValues = valueList.toArray();
108
109 return new GString(newValues) {
110 public String[] getStrings() {
111 return newStrings;
112 }
113 };
114 }
115
116 public GString plus(String that) {
117 String[] currentStrings = getStrings();
118 String[] newStrings = null;
119 Object[] newValues = null;
120
121 newStrings = new String[currentStrings.length + 1];
122 newValues = new Object[getValues().length + 1];
123 int lastIndex = currentStrings.length;
124 System.arraycopy(currentStrings, 0, newStrings, 0, lastIndex);
125 System.arraycopy(getValues(), 0, newValues, 0, getValues().length);
126 newStrings[lastIndex] = that;
127 newValues[getValues().length] = "";
128
129 final String[] finalStrings = newStrings;
130 return new GString(newValues) {
131
132 public String[] getStrings() {
133 return finalStrings;
134 }
135 };
136 }
137
138 public int getValueCount() {
139 return values.length;
140 }
141
142 public Object getValue(int idx) {
143 return values[idx];
144 }
145
146 public String toString() {
147 StringWriter buffer = new StringWriter();
148 try {
149 writeTo(buffer);
150 }
151 catch (IOException e) {
152 throw new StringWriterIOException(e);
153 }
154 return buffer.toString();
155 }
156
157 public Writer writeTo(Writer out) throws IOException {
158 String[] s = getStrings();
159 int numberOfValues = values.length;
160 for (int i = 0, size = s.length; i < size; i++) {
161 out.write(s[i]);
162 if (i < numberOfValues) {
163 InvokerHelper.write(out, values[i]);
164 }
165 }
166 return out;
167 }
168
169 public boolean equals(Object that) {
170 if (that instanceof GString) {
171 return equals((GString) that);
172 }
173 return false;
174 }
175
176 public boolean equals(GString that) {
177 return toString().equals(that.toString());
178 }
179
180 public int hashCode() {
181 return 37 + toString().hashCode();
182 }
183
184 public int compareTo(Object that) {
185 return toString().compareTo(that.toString());
186 }
187
188 public char charAt(int index) {
189 return toString().charAt(index);
190 }
191
192 public int length() {
193 return toString().length();
194 }
195
196 public CharSequence subSequence(int start, int end) {
197 return toString().subSequence(start, end);
198 }
199 }