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
060: Comparable, CharSequence, Writable, Buildable {
061:
062: private Object[] values;
063:
064: public GString(Object values) {
065: this .values = (Object[]) values;
066: }
067:
068: public GString(Object[] values) {
069: this .values = values;
070: }
071:
072: // will be static in an instance
073: public abstract String[] getStrings();
074:
075: /**
076: * Overloaded to implement duck typing for Strings
077: * so that any method that can't be evaluated on this
078: * object will be forwarded to the toString() object instead.
079: */
080: public Object invokeMethod(String name, Object args) {
081: try {
082: return super .invokeMethod(name, args);
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,
128: getValues().length);
129: newStrings[lastIndex] = that;
130: newValues[getValues().length] = "";
131:
132: final String[] finalStrings = newStrings;
133: return new GString(newValues) {
134:
135: public String[] getStrings() {
136: return finalStrings;
137: }
138: };
139: }
140:
141: public int getValueCount() {
142: return values.length;
143: }
144:
145: public Object getValue(int idx) {
146: return values[idx];
147: }
148:
149: public String toString() {
150: StringWriter buffer = new StringWriter();
151: try {
152: writeTo(buffer);
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",
184: new Object[] { values[i] });
185: }
186: }
187: }
188:
189: public boolean equals(Object that) {
190: if (that instanceof GString) {
191: return equals((GString) that);
192: }
193: return false;
194: }
195:
196: public boolean equals(GString that) {
197: return toString().equals(that.toString());
198: }
199:
200: public int hashCode() {
201: return 37 + toString().hashCode();
202: }
203:
204: public int compareTo(Object that) {
205: return toString().compareTo(that.toString());
206: }
207:
208: public char charAt(int index) {
209: return toString().charAt(index);
210: }
211:
212: public int length() {
213: return toString().length();
214: }
215:
216: public CharSequence subSequence(int start, int end) {
217: return toString().subSequence(start, end);
218: }
219:
220: /**
221: * Turns a String into a regular expression pattern
222: *
223: * @return the regular expression pattern
224: */
225: public Pattern negate() {
226: return DefaultGroovyMethods.negate(toString());
227: }
228: }
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