001 /*
002 * $Id: GString.java 4098 2006-10-10 16:09:48Z blackdrag $
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 import java.util.regex.Pattern;
043
044 import org.codehaus.groovy.runtime.DefaultGroovyMethods;
045 import org.codehaus.groovy.runtime.InvokerHelper;
046
047 /**
048 * Represents a String which contains embedded values such as "hello there
049 * ${user} how are you?" which can be evaluated lazily. Advanced users can
050 * iterate over the text and values to perform special processing, such as for
051 * performing SQL operations, the values can be substituted for ? and the
052 * actual value objects can be bound to a JDBC statement. The lovely name of
053 * this class was suggested by Jules Gosnell and was such a good idea, I
054 * couldn't resist :)
055 *
056 * @author <a href="mailto:james@coredevelopers.net">James Strachan</a>
057 * @version $Revision: 4098 $
058 */
059 public abstract class GString extends GroovyObjectSupport implements Comparable, CharSequence, Writable, Buildable {
060
061 private Object[] values;
062
063 public GString(Object values) {
064 this.values = (Object[]) values;
065 }
066
067 public GString(Object[] values) {
068 this.values = values;
069 }
070
071 // will be static in an instance
072 public abstract String[] getStrings();
073
074 /**
075 * Overloaded to implement duck typing for Strings
076 * so that any method that can't be evaluated on this
077 * object will be forwarded to the toString() object instead.
078 */
079 public Object invokeMethod(String name, Object args) {
080 try {
081 return super.invokeMethod(name, args);
082 }
083 catch (MissingMethodException e) {
084 // lets try invoke the method on the real String
085 return InvokerHelper.invokeMethod(toString(), name, args);
086 }
087 }
088
089 public Object[] getValues() {
090 return values;
091 }
092
093 public GString plus(GString that) {
094 List stringList = new ArrayList();
095 List valueList = new ArrayList();
096
097 stringList.addAll(Arrays.asList(getStrings()));
098 valueList.addAll(Arrays.asList(getValues()));
099
100 if (stringList.size() > valueList.size()) {
101 valueList.add("");
102 }
103
104 stringList.addAll(Arrays.asList(that.getStrings()));
105 valueList.addAll(Arrays.asList(that.getValues()));
106
107 final String[] newStrings = new String[stringList.size()];
108 stringList.toArray(newStrings);
109 Object[] newValues = valueList.toArray();
110
111 return new GString(newValues) {
112 public String[] getStrings() {
113 return newStrings;
114 }
115 };
116 }
117
118 public GString plus(String that) {
119 String[] currentStrings = getStrings();
120 String[] newStrings = null;
121 Object[] newValues = null;
122
123 newStrings = new String[currentStrings.length + 1];
124 newValues = new Object[getValues().length + 1];
125 int lastIndex = currentStrings.length;
126 System.arraycopy(currentStrings, 0, newStrings, 0, lastIndex);
127 System.arraycopy(getValues(), 0, newValues, 0, getValues().length);
128 newStrings[lastIndex] = that;
129 newValues[getValues().length] = "";
130
131 final String[] finalStrings = newStrings;
132 return new GString(newValues) {
133
134 public String[] getStrings() {
135 return finalStrings;
136 }
137 };
138 }
139
140 public int getValueCount() {
141 return values.length;
142 }
143
144 public Object getValue(int idx) {
145 return values[idx];
146 }
147
148 public String toString() {
149 StringWriter buffer = new StringWriter();
150 try {
151 writeTo(buffer);
152 }
153 catch (IOException e) {
154 throw new StringWriterIOException(e);
155 }
156 return buffer.toString();
157 }
158
159 public Writer writeTo(Writer out) throws IOException {
160 String[] s = getStrings();
161 int numberOfValues = values.length;
162 for (int i = 0, size = s.length; i < size; i++) {
163 out.write(s[i]);
164 if (i < numberOfValues) {
165 InvokerHelper.write(out, values[i]);
166 }
167 }
168 return out;
169 }
170
171 /* (non-Javadoc)
172 * @see groovy.lang.Buildable#build(groovy.lang.GroovyObject)
173 */
174 public void build(final GroovyObject builder) {
175 final String[] s = getStrings();
176 final int numberOfValues = values.length;
177
178 for (int i = 0, size = s.length; i < size; i++) {
179 builder.getProperty("mkp");
180 builder.invokeMethod("yield", new Object[]{s[i]});
181 if (i < numberOfValues) {
182 builder.getProperty("mkp");
183 builder.invokeMethod("yield", new Object[]{values[i]});
184 }
185 }
186 }
187
188 public boolean equals(Object that) {
189 if (that instanceof GString) {
190 return equals((GString) that);
191 }
192 return false;
193 }
194
195 public boolean equals(GString that) {
196 return toString().equals(that.toString());
197 }
198
199 public int hashCode() {
200 return 37 + toString().hashCode();
201 }
202
203 public int compareTo(Object that) {
204 return toString().compareTo(that.toString());
205 }
206
207 public char charAt(int index) {
208 return toString().charAt(index);
209 }
210
211 public int length() {
212 return toString().length();
213 }
214
215 public CharSequence subSequence(int start, int end) {
216 return toString().subSequence(start, end);
217 }
218
219 /**
220 * Turns a String into a regular expression pattern
221 *
222 * @return the regular expression pattern
223 */
224 public Pattern negate() {
225 return DefaultGroovyMethods.negate(toString());
226 }
227 }