001 package org.apache.commons.ognl;
002
003 /*
004 * Licensed to the Apache Software Foundation (ASF) under one
005 * or more contributor license agreements. See the NOTICE file
006 * distributed with this work for additional information
007 * regarding copyright ownership. The ASF licenses this file
008 * to you under the Apache License, Version 2.0 (the
009 * "License"); you may not use this file except in compliance
010 * with the License. You may obtain a copy of the License at
011 *
012 * http://www.apache.org/licenses/LICENSE-2.0
013 *
014 * Unless required by applicable law or agreed to in writing,
015 * software distributed under the License is distributed on an
016 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
017 * KIND, either express or implied. See the License for the
018 * specific language governing permissions and limitations
019 * under the License.
020 */
021
022 import java.util.*;
023
024 /**
025 * Implementation of PropertyAccessor that uses numbers and dynamic subscripts as properties to index into Lists.
026 *
027 * @author Luke Blanshard (blanshlu@netscape.net)
028 * @author Drew Davidson (drew@ognl.org)
029 */
030 public class ListPropertyAccessor
031 extends ObjectPropertyAccessor
032 implements PropertyAccessor
033 {
034
035 @Override
036 public Object getProperty( Map<String, Object> context, Object target, Object name )
037 throws OgnlException
038 {
039 List<?> list = (List<?>) target;
040
041 if ( name instanceof String )
042 {
043 Object result;
044
045 if ( "size".equals( name ) )
046 {
047 result = list.size();
048 }
049 else
050 {
051 if ( "iterator".equals( name ) )
052 {
053 result = list.iterator();
054 }
055 else
056 {
057 if ( "isEmpty".equals( name ) || "empty".equals( name ) )
058 {
059 result = list.isEmpty() ? Boolean.TRUE : Boolean.FALSE;
060 }
061 else
062 {
063 result = super.getProperty( context, target, name );
064 }
065 }
066 }
067
068 return result;
069 }
070
071 if ( name instanceof Number )
072 {
073 return list.get( ( (Number) name ).intValue() );
074 }
075
076 if ( name instanceof DynamicSubscript )
077 {
078 int len = list.size();
079 switch ( ( (DynamicSubscript) name ).getFlag() )
080 {
081 case DynamicSubscript.FIRST:
082 return len > 0 ? list.get( 0 ) : null;
083 case DynamicSubscript.MID:
084 return len > 0 ? list.get( len / 2 ) : null;
085 case DynamicSubscript.LAST:
086 return len > 0 ? list.get( len - 1 ) : null;
087 case DynamicSubscript.ALL:
088 return new ArrayList<Object>( list );
089 default:
090 break;
091 }
092 }
093
094 throw new NoSuchPropertyException( target, name );
095 }
096
097 @Override
098 public void setProperty( Map<String, Object> context, Object target, Object name, Object value )
099 throws OgnlException
100 {
101 if ( name instanceof String && !( (String) name ).contains( "$" ) )
102 {
103 super.setProperty( context, target, name, value );
104 return;
105 }
106
107 @SuppressWarnings( "unchecked" ) // check performed by the invoker
108 List<Object> list = (List<Object>) target;
109
110 if ( name instanceof Number )
111 {
112 list.set( ( (Number) name ).intValue(), value );
113 return;
114 }
115
116 if ( name instanceof DynamicSubscript )
117 {
118 int len = list.size();
119 switch ( ( (DynamicSubscript) name ).getFlag() )
120 {
121 case DynamicSubscript.FIRST:
122 if ( len > 0 )
123 {
124 list.set( 0, value );
125 }
126 return;
127 case DynamicSubscript.MID:
128 if ( len > 0 )
129 {
130 list.set( len / 2, value );
131 }
132 return;
133 case DynamicSubscript.LAST:
134 if ( len > 0 )
135 {
136 list.set( len - 1, value );
137 }
138 return;
139 case DynamicSubscript.ALL:
140 if ( !( value instanceof Collection ) )
141 {
142 throw new OgnlException( "Value must be a collection" );
143 }
144 list.clear();
145 list.addAll( (Collection<?>) value );
146 return;
147 default:
148 return;
149 }
150 }
151
152 throw new NoSuchPropertyException( target, name );
153 }
154
155 @Override
156 public Class<?> getPropertyClass( OgnlContext context, Object target, Object index )
157 {
158 if ( index instanceof String )
159 {
160 String key = ( (String) index ).replaceAll( "\"", "" );
161 if ( "size".equals( key ) )
162 {
163 return int.class;
164 }
165 if ( "iterator".equals( key ) )
166 {
167 return Iterator.class;
168 }
169 if ( "isEmpty".equals( key ) || "empty".equals( key ) )
170 {
171 return boolean.class;
172 }
173 return super.getPropertyClass( context, target, index );
174 }
175
176 if ( index instanceof Number )
177 {
178 return Object.class;
179 }
180
181 return null;
182 }
183
184 @Override
185 public String getSourceAccessor( OgnlContext context, Object target, Object index )
186 {
187 String indexStr = index.toString().replaceAll( "\"", "" );
188
189 if ( String.class.isInstance( index ) )
190 {
191 if ( "size".equals( indexStr ) )
192 {
193 context.setCurrentAccessor( List.class );
194 context.setCurrentType( int.class );
195 return ".size()";
196 }
197 if ( "iterator".equals( indexStr ) )
198 {
199 context.setCurrentAccessor( List.class );
200 context.setCurrentType( Iterator.class );
201 return ".iterator()";
202 }
203 if ( "isEmpty".equals( indexStr ) || "empty".equals( indexStr ) )
204 {
205 context.setCurrentAccessor( List.class );
206 context.setCurrentType( boolean.class );
207 return ".isEmpty()";
208 }
209 }
210
211 // TODO: This feels really inefficient, must be some better way
212 // check if the index string represents a method on a custom class implementing java.util.List instead..
213 return getSourceBeanMethod( context, target, index, indexStr, false );
214 }
215
216 @Override
217 public String getSourceSetter( OgnlContext context, Object target, Object index )
218 {
219 String indexStr = index.toString().replaceAll( "\"", "" );
220
221 // TODO: This feels really inefficient, must be some better way
222 // check if the index string represents a method on a custom class implementing java.util.List instead..
223 /*
224 * System.out.println("Listpropertyaccessor setter using index: " + index + " and current object: " +
225 * context.getCurrentObject() + " number is current object? " +
226 * Number.class.isInstance(context.getCurrentObject()));
227 */
228
229 return getSourceBeanMethod( context, target, index, indexStr, true );
230 }
231
232 private String getSourceBeanMethod( OgnlContext context, Object target, Object index, String indexStr,
233 boolean isSetter )
234 {
235 Object currentObject = context.getCurrentObject();
236 Class<?> currentType = context.getCurrentType();
237 if ( currentObject != null && !Number.class.isInstance( currentObject ) )
238 {
239 try
240 {
241 if ( isSetter )
242 {
243 if ( OgnlRuntime.getWriteMethod( target.getClass(), indexStr ) != null
244 || !currentType.isPrimitive() )
245 {
246 return super.getSourceSetter( context, target, index );
247 }
248 }
249 else
250 {
251 if ( OgnlRuntime.getReadMethod( target.getClass(), indexStr ) != null )
252 {
253 return super.getSourceAccessor( context, target, index );
254 }
255 }
256 }
257 catch ( Throwable t )
258 {
259 throw OgnlOps.castToRuntime( t );
260 }
261 }
262
263 /*
264 * if (String.class.isInstance(index)) { context.setCurrentAccessor(List.class); return ""; }
265 */
266
267 context.setCurrentAccessor( List.class );
268
269 // need to convert to primitive for list index access
270
271 if ( !currentType.isPrimitive() && Number.class.isAssignableFrom( currentType ) )
272 {
273 indexStr += "." + OgnlRuntime.getNumericValueGetter( currentType );
274 }
275 else if ( currentObject != null && Number.class.isAssignableFrom( currentObject.getClass() )
276 && !currentType.isPrimitive() )
277 {
278 // means it needs to be cast first as well
279
280 String toString = String.class.isInstance( index ) && currentType != Object.class ? "" : ".toString()";
281
282 indexStr = "org.apache.commons.ognl.OgnlOps#getIntValue(" + indexStr + toString + ")";
283 }
284
285 context.setCurrentType( Object.class );
286
287 return isSetter ? ".set(" + indexStr + ", $3)" : ".get(" + indexStr + ")";
288 }
289
290 }