1 /* IndexedPropertyDescriptor.java --
2 Copyright (C) 1998, 2003 Free Software Foundation, Inc.
4 This file is part of GNU Classpath.
6 GNU Classpath is free software; you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by
8 the Free Software Foundation; either version 2, or (at your option)
11 GNU Classpath is distributed in the hope that it will be useful, but
12 WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 General Public License for more details.
16 You should have received a copy of the GNU General Public License
17 along with GNU Classpath; see the file COPYING. If not, write to the
18 Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
21 Linking this library statically or dynamically with other modules is
22 making a combined work based on this library. Thus, the terms and
23 conditions of the GNU General Public License cover the whole
26 As a special exception, the copyright holders of this library give you
27 permission to link this library with independent modules to produce an
28 executable, regardless of the license terms of these independent
29 modules, and to copy and distribute the resulting executable under
30 terms of your choice, provided that you also meet, for each linked
31 independent module, the terms and conditions of the license of that
32 module. An independent module is a module which is not derived from
33 or based on this library. If you modify this library, you may extend
34 this exception to your version of the library, but you are not
35 obligated to do so. If you do not wish to do so, delete this
36 exception statement from your version. */
41 import java
.lang
.reflect
.Array
;
42 import java
.lang
.reflect
.Method
;
45 * IndexedPropertyDescriptor describes information about a JavaBean
46 * indexed property, by which we mean an array-like property that
47 * has been exposed via a pair of get and set methods and another
48 * pair that allows you to get to the property by an index.<P>
50 * An example property would have four methods like this:<P>
51 * <CODE>FooBar[] getFoo()</CODE><BR>
52 * <CODE>void setFoo(FooBar[])</CODE><BR>
53 * <CODE>FooBar getFoo(int)</CODE><BR>
54 * <CODE>void setFoo(int,FooBar)</CODE><P>
56 * The constraints put on get and set methods are:<P>
58 * <LI>There must be at least a get(int) or a set(int,...) method.
59 * Nothing else is required. <B>Spec note:</B>One nice restriction
60 * would be that if there is a get() there must be a get(int), same
61 * with set, but that is not in the spec and is fairly harmless.)</LI>
62 * <LI>A get array method must have signature
63 * <CODE><propertyType>[] <getMethodName>()</CODE></LI>
64 * <LI>A set array method must have signature
65 * <CODE>void <setMethodName>(<propertyType>[])</CODE></LI>
66 * <LI>A get index method must have signature
67 * <CODE><propertyType> <getMethodName>(int)</CODE></LI>
68 * <LI>A set index method must have signature
69 * <CODE>void <setMethodName>(int,<propertyType>)</CODE></LI>
70 * <LI>All these methods may throw any exception.</LI>
71 * <LI>All these methods must be public.</LI>
77 public class IndexedPropertyDescriptor
extends PropertyDescriptor
79 private Class indexedPropertyType
;
80 private Method setIndex
;
81 private Method getIndex
;
84 * Create a new IndexedPropertyDescriptor by introspection.
85 * This form of constructor creates the PropertyDescriptor by
86 * looking for getter methods named <CODE>get<name>()</CODE>
87 * and setter methods named
88 * <CODE>set<name>()</CODE> in class
89 * <CODE><beanClass></CODE>, where <name> has its
90 * first letter capitalized by the constructor.<P>
92 * <B>Implementation note:</B> If there is a get(int) method,
93 * then the return type of that method is used to find the
94 * remaining methods. If there is no get method, then the
95 * set(int) method is searched for exhaustively and that type
96 * is used to find the others.<P>
99 * If there is no get(int) method and multiple set(int) methods with
100 * the same name and the correct parameters (different type of course),
101 * then an IntrospectionException is thrown. While Sun's spec
102 * does not state this, it can make Bean behavior different on
103 * different systems (since method order is not guaranteed) and as
104 * such, can be treated as a bug in the spec. I am not aware of
105 * whether Sun's implementation catches this.
107 * @param name the programmatic name of the property, usually
108 * starting with a lowercase letter (e.g. fooManChu
109 * instead of FooManChu).
110 * @param beanClass the class the get and set methods live in.
112 * @exception IntrospectionException if the methods are not found or
115 public IndexedPropertyDescriptor(String name
, Class beanClass
)
116 throws IntrospectionException
122 capitalized
= Character
.toUpperCase(name
.charAt(0))
125 catch(StringIndexOutOfBoundsException e
)
129 findMethods(beanClass
, "get" + capitalized
, "set" + capitalized
,
130 "get" + capitalized
, "set" + capitalized
);
134 * Create a new IndexedPropertyDescriptor by introspection.
135 * This form of constructor allows you to specify the
136 * names of the get and set methods to search for.<P>
138 * <B>Implementation note:</B> If there is a get(int) method,
139 * then the return type of that method is used to find the
140 * remaining methods. If there is no get method, then the
141 * set(int) method is searched for exhaustively and that type
142 * is used to find the others.<P>
145 * If there is no get(int) method and multiple set(int) methods with
146 * the same name and the correct parameters (different type of course),
147 * then an IntrospectionException is thrown. While Sun's spec
148 * does not state this, it can make Bean behavior different on
149 * different systems (since method order is not guaranteed) and as
150 * such, can be treated as a bug in the spec. I am not aware of
151 * whether Sun's implementation catches this.
153 * @param name the programmatic name of the property, usually
154 * starting with a lowercase letter (e.g. fooManChu
155 * instead of FooManChu).
156 * @param beanClass the class the get and set methods live in.
157 * @param getMethodName the name of the get array method.
158 * @param setMethodName the name of the set array method.
159 * @param getIndexName the name of the get index method.
160 * @param setIndexName the name of the set index method.
162 * @exception IntrospectionException if the methods are not found or invalid.
164 public IndexedPropertyDescriptor(String name
, Class beanClass
,
165 String getMethodName
, String setMethodName
,
166 String getIndexName
, String setIndexName
)
167 throws IntrospectionException
170 findMethods(beanClass
, getMethodName
, setMethodName
, getIndexName
,
175 * Create a new PropertyDescriptor using explicit Methods.
176 * Note that the methods will be checked for conformance to standard
177 * Property method rules, as described above at the top of this class.
179 * @param name the programmatic name of the property, usually
180 * starting with a lowercase letter (e.g. fooManChu
181 * instead of FooManChu).
182 * @param getMethod the get array method.
183 * @param setMethod the set array method.
184 * @param getIndex the get index method.
185 * @param setIndex the set index method.
187 * @exception IntrospectionException if the methods are not found or invalid.
189 public IndexedPropertyDescriptor(String name
, Method getMethod
,
190 Method setMethod
, Method getIndex
,
192 throws IntrospectionException
195 if(getMethod
!= null && getMethod
.getParameterTypes().length
> 0)
196 throw new IntrospectionException("get method has parameters");
197 if(getMethod
!= null && setMethod
.getParameterTypes().length
!= 1)
198 throw new IntrospectionException("set method does not have exactly one parameter");
199 if(getMethod
!= null && setMethod
!= null)
201 if(!getMethod
.getReturnType().equals(setMethod
.getParameterTypes()[0]))
203 throw new IntrospectionException("set and get methods do not "
204 + "share the same type");
206 if(!getMethod
.getDeclaringClass().isAssignableFrom
207 (setMethod
.getDeclaringClass())
208 && !setMethod
.getDeclaringClass().isAssignableFrom
209 (getMethod
.getDeclaringClass()))
211 throw new IntrospectionException("set and get methods are not in "
212 + "the same class.");
217 && (getIndex
.getParameterTypes().length
!= 1
218 || !(getIndex
.getParameterTypes()[0]).equals(java
.lang
.Integer
.TYPE
)))
220 throw new IntrospectionException("get index method has wrong "
224 && (setIndex
.getParameterTypes().length
!= 2
225 || !(setIndex
.getParameterTypes()[0]).equals(java
.lang
.Integer
.TYPE
)))
227 throw new IntrospectionException("set index method has wrong "
230 if (getIndex
!= null && setIndex
!= null)
232 if(!getIndex
.getReturnType().equals(setIndex
.getParameterTypes()[1]))
234 throw new IntrospectionException("set index methods do not share "
237 if(!getIndex
.getDeclaringClass().isAssignableFrom
238 (setIndex
.getDeclaringClass())
239 && !setIndex
.getDeclaringClass().isAssignableFrom
240 (getIndex
.getDeclaringClass()))
242 throw new IntrospectionException("get and set index methods are "
243 + "not in the same class.");
247 if (getIndex
!= null && getMethod
!= null
248 && !getIndex
.getDeclaringClass().isAssignableFrom
249 (getMethod
.getDeclaringClass())
250 && !getMethod
.getDeclaringClass().isAssignableFrom
251 (getIndex
.getDeclaringClass()))
253 throw new IntrospectionException("methods are not in the same class.");
256 if (getIndex
!= null && getMethod
!= null
257 && !Array
.newInstance(getIndex
.getReturnType(),0)
258 .getClass().equals(getMethod
.getReturnType()))
260 throw new IntrospectionException("array methods do not match index "
264 this.getMethod
= getMethod
;
265 this.setMethod
= setMethod
;
266 this.getIndex
= getIndex
;
267 this.setIndex
= setIndex
;
268 this.indexedPropertyType
= getIndex
!= null ? getIndex
.getReturnType()
269 : setIndex
.getParameterTypes()[1];
270 this.propertyType
= getMethod
!= null ? getMethod
.getReturnType()
271 : (setMethod
!= null ? setMethod
.getParameterTypes()[0]
272 : Array
.newInstance(this.indexedPropertyType
,0).getClass());
275 public Class
getIndexedPropertyType()
277 return indexedPropertyType
;
280 public Method
getIndexedReadMethod()
286 * Sets the method that is used to read an indexed property.
288 * @param m the method to set
290 public void setIndexedReadMethod(Method m
) throws IntrospectionException
295 public Method
getIndexedWriteMethod()
301 * Sets the method that is used to write an indexed property.
303 * @param m the method to set
305 public void setIndexedWriteMethod(Method m
) throws IntrospectionException
310 private void findMethods(Class beanClass
, String getMethodName
,
311 String setMethodName
, String getIndexName
,
313 throws IntrospectionException
317 if(getIndexName
!= null)
321 Class
[] getArgs
= new Class
[1];
322 getArgs
[0] = java
.lang
.Integer
.TYPE
;
323 getIndex
= beanClass
.getMethod(getIndexName
,getArgs
);
324 indexedPropertyType
= getIndex
.getReturnType();
326 catch(NoSuchMethodException E
)
332 if(setIndexName
!= null)
336 Class
[] setArgs
= new Class
[2];
337 setArgs
[0] = java
.lang
.Integer
.TYPE
;
338 setArgs
[1] = indexedPropertyType
;
339 setIndex
= beanClass
.getMethod(setIndexName
,setArgs
);
340 if(!setIndex
.getReturnType().equals(java
.lang
.Void
.TYPE
))
342 throw new IntrospectionException(setIndexName
343 + " has non-void return type");
346 catch(NoSuchMethodException E
)
351 else if(setIndexName
!= null)
353 Method
[] m
= beanClass
.getMethods();
354 for(int i
=0;i
<m
.length
;i
++)
356 Method current
= m
[i
];
357 if(current
.getName().equals(setIndexName
)
358 && current
.getParameterTypes().length
== 2
359 && (current
.getParameterTypes()[0])
360 .equals(java
.lang
.Integer
.TYPE
)
361 && current
.getReturnType().equals(java
.lang
.Void
.TYPE
))
365 throw new IntrospectionException("Multiple, different "
366 + "set methods found that fit the bill!");
371 indexedPropertyType
= current
.getParameterTypes()[1];
377 throw new IntrospectionException("Cannot find get or set "
383 throw new IntrospectionException("Cannot find get or set methods.");
386 Class arrayType
= Array
.newInstance(indexedPropertyType
,0).getClass();
388 Class
[] setArgs
= new Class
[1];
389 setArgs
[0] = arrayType
;
392 setMethod
= beanClass
.getMethod(setMethodName
,setArgs
);
393 if (!setMethod
.getReturnType().equals(java
.lang
.Void
.TYPE
))
398 catch(NoSuchMethodException E
)
402 Class
[] getArgs
= new Class
[0];
405 getMethod
= beanClass
.getMethod(getMethodName
,getArgs
);
406 if (!getMethod
.getReturnType().equals(arrayType
))
411 catch(NoSuchMethodException E
)
415 catch(SecurityException E
)
417 throw new IntrospectionException("SecurityException while trying to "