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1 package jfun.yan.xml.nut;
2
3
4 import java.beans.BeanInfo  ;
5 import java.beans.IndexedPropertyDescriptor ;
6 import java.beans.IntrospectionException ;
7 import java.beans.Introspector ;
8 import java.beans.PropertyDescriptor ;
9 import java.lang.reflect.InvocationTargetException ;
10 import java.lang.reflect.Method ;
11 import java.util.ArrayList ;
12 import java.util.HashMap ;
13 import java.util.Locale ;
14 import java.util.Map ;
15
16 import jfun.yan.Binder;
17 import jfun.yan.Component;
18 import jfun.yan.xml.ConfigurationException;
19
20
21
22
23
30 public class NutIntrospector implements java.io.Serializable {
31 private final HashMap cache = new HashMap ();
32
38 public NutDescriptor getNutDescriptor(final Class type)
39 throws IntrospectionException {
40 NutDescriptor desc = (NutDescriptor)cache.get(type);
41 if(desc == null){
42 if(!Nut.class.isAssignableFrom(type)){
43 throw new IllegalArgumentException ("only Nut class is introspectable.");
44 }
45
52 desc = new NutDescriptor(type);
53 cache.put(type, desc);
54 final Evaluator evaluator = getEvaluator(type);
55 desc.setEvaluator(evaluator);
56 desc.setPropertyDescriptors(getProperties(type));
57 populateSub(type, desc);
58 }
59 return desc;
60 }
61 private Evaluator getEvaluator(final Class type){
62 if(ComponentNut.class.isAssignableFrom(type)){
63 return new Evaluator(){
64 public Object eval(Object obj)
65 throws Exception {
66 final ComponentNut nut = (ComponentNut)obj;
67 return nut.eval();
68 }
69 public Class getType(){
70 return Component.class;
71 }
72 };
73 }
74 else if(BinderNut.class.isAssignableFrom(type)){
75 return new Evaluator(){
76 public Object eval(Object obj) {
77 final BinderNut nut = (BinderNut)obj;
78 try{
79 return nut.eval();
80 }
81 catch(Exception e){
82 throw new ConfigurationException(e, nut.getTagLocation());
83 }
84 }
85 public Class getType(){
86 return Binder.class;
87 }
88 };
89 }
90 else{
91 try{
92 final Method mtd = type.getMethod("eval", null);
93 final Class rtype = mtd.getReturnType();
94 return new Evaluator(){
95 public Object eval(Object obj){
96 final Nut nut = (Nut)obj;
97 try{
98 final Object r = mtd.invoke(nut, null);
99 if(void.class.equals(rtype)){
100 return nut;
101 }
102 else return r;
103 }
104 catch(InvocationTargetException e){
105 throw new ConfigurationException(e.getTargetException(), nut.getTagLocation());
106 }
107 catch(Exception e){
108 throw new ConfigurationException(e, nut.getTagLocation());
109 }
110 }
111 public Class getType(){
112 return (void.class.equals(rtype)?type:rtype);
113 }
114 };
115 }
116 catch(NoSuchMethodException e){
117 return new Evaluator(){
118 public Object eval(Object nut){
119 return nut;
120 }
121 public Class getType(){
122 return type;
123 }
124 };
125 }
126 }
127 }
128
129 private Map getProperties(Class type)
130 throws IntrospectionException {
131 final BeanInfo info = Introspector.getBeanInfo(type);
132 final PropertyDescriptor [] pdescs = info.getPropertyDescriptors();
133 final HashMap ret = new HashMap ();
134 for(int i=0; i<pdescs.length; i++){
135 final PropertyDescriptor desc = pdescs[i];
136 if(desc.getWriteMethod()!=null && !(desc instanceof IndexedPropertyDescriptor )){
137 ret.put(desc.getName(), desc);
138 }
139 }
140 return ret;
141 }
142 private final void populateSub(Class type, NutDescriptor desc)
145 throws IntrospectionException {
146 final HashMap subs= new HashMap ();
147 final Method [] mtds = type.getMethods();
148 final ArrayList anonymous_adders = new ArrayList ();
149 Class etype = null;
150 Method r = null;
151 for(int i=0; i<mtds.length; i++){
152 final Method mtd = mtds[i];
153 final String mname = mtd.getName();
154 if(mname.equals("set")){
155 final Class [] ptypes = mtd.getParameterTypes();
156 if(ptypes.length != 1){
157 continue;
158 }
159 final Class ptype = ptypes[0];
160 if(!ptype.isArray()){
161 continue;
162 }
163 final Class etype2 = ptype.getComponentType();
164 if(etype != null){
165 if(etype.isAssignableFrom(etype2)){
166 etype = etype2;
168 r = mtd;
169 }
170 }
171 else{
172 r = mtd;
173 etype = etype2;
174 }
175 }
176 else if(mname.startsWith(ADDER)){
177 final Class [] ptypes = mtd.getParameterTypes();
178 if(ptypes.length!=1){
179 continue;
180 }
181 Class ptype = ptypes[0];
182 final String elem_name = mname.substring(3).toLowerCase(Locale.US);
183 if(subs.containsKey(elem_name)){
184 throw new IllegalArgumentException ("duplicate adder: "+mname);
185 }
186 if(elem_name.length()==0){
187
192 anonymous_adders.add(new Method1(mtd, ptype));
193 }
194 else{
195 if(!Nut.class.isAssignableFrom(ptype))
196 continue;
197 desc.putAdder(elem_name, mtd);
198 if(elem_name.length()>0){
199 subs.put(elem_name, getNutDescriptor(ptype));
200 }
201 }
202 }
203 }
204 if(r!=null){
205 desc.setCollectionDescriptor(
206 new NutDescriptor.CollectionDescriptor(etype, r)
207 );
208 }
209 else{
210 desc.setRegularDescriptor(
211 new NutDescriptor.RegularDescriptor(subs)
212 );
213 }
214 final Method1[] anonymous = new Method1[anonymous_adders.size()];
215 anonymous_adders.toArray(anonymous);
216 desc.setAdderSuite(new MethodSuite(ADDER, anonymous));
217 }
218 private static final String ADDER = "add";
219 }
220 |
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