1 |
| package org.drools.semantics.annotation.model; |
2 |
| |
3 |
| import java.lang.annotation.Annotation; |
4 |
| import java.lang.reflect.Method; |
5 |
| import java.util.ArrayList; |
6 |
| import java.util.HashSet; |
7 |
| import java.util.List; |
8 |
| import java.util.Set; |
9 |
| |
10 |
| import org.drools.DroolsException; |
11 |
| import org.drools.rule.Declaration; |
12 |
| import org.drools.rule.InvalidRuleException; |
13 |
| import org.drools.rule.Rule; |
14 |
| import org.drools.semantics.annotation.DroolsParameter; |
15 |
| import org.drools.semantics.annotation.DroolsApplicationData; |
16 |
| import org.drools.semantics.annotation.DroolsCondition; |
17 |
| import org.drools.semantics.annotation.DroolsConsequence; |
18 |
| import org.drools.semantics.base.ClassObjectType; |
19 |
| import org.drools.spi.Consequence; |
20 |
| import org.drools.spi.KnowledgeHelper; |
21 |
| |
22 |
| public class AnnonatedPojoRuleBuilder |
23 |
| { |
24 |
| |
25 |
| private static final Set<ParameterValueFactory> parameterValueFatories |
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| = new HashSet<ParameterValueFactory>(); |
27 |
| |
28 |
| static { |
29 |
4
| registerParameterValueFactory(new KnowledgeHelperParameterValueFactory());
|
30 |
4
| registerParameterValueFactory(new DroolsTupleParameterValueFactory());
|
31 |
4
| registerParameterValueFactory(new DroolsApplicationDataParameterValueFactory());
|
32 |
| } |
33 |
| |
34 |
12
| public static void registerParameterValueFactory( ParameterValueFactory factory)
|
35 |
| { |
36 |
12
| for (ParameterValueFactory registeredFactory : parameterValueFatories) {
|
37 |
12
| if (factory.getParameterValueType() == registeredFactory.getParameterValueType()) {
|
38 |
0
| throw new IllegalArgumentException("ParameterValueFactory already registered"
|
39 |
| + ": type=" + factory.getParameterValueType() |
40 |
| + ", factory =" + factory |
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| + ", registered factory=" + registeredFactory); |
42 |
| } |
43 |
| } |
44 |
12
| parameterValueFatories.add(factory);
|
45 |
| } |
46 |
| |
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| private static interface ParameterValidator |
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| { |
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| void assertParameter( ParameterValue newParameterValue, List<ParameterValue> parameterValues ) |
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| throws DroolsException; |
51 |
| } |
52 |
| |
53 |
17
| public Rule buildRule( Rule rule, Object pojo ) throws DroolsException
|
54 |
| { |
55 |
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| Class< ? > ruleClass = pojo.getClass( );
|
56 |
17
| buildConditions( rule, ruleClass, pojo );
|
57 |
14
| buildConsequence( rule, ruleClass, pojo );
|
58 |
9
| return rule;
|
59 |
| } |
60 |
| |
61 |
17
| private static void buildConditions( Rule rule, Class< ? > ruleClass, Object pojo )
|
62 |
| throws DroolsException |
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| { |
64 |
17
| for (Method method : ruleClass.getMethods( ))
|
65 |
| { |
66 |
164
| DroolsCondition conditionAnnotation = method.getAnnotation( DroolsCondition.class );
|
67 |
164
| if (conditionAnnotation != null)
|
68 |
| { |
69 |
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| PojoCondition condition = newPojoCondition( rule, pojo, method );
|
70 |
11
| rule.addCondition( condition );
|
71 |
| } |
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| } |
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| } |
74 |
| |
75 |
14
| private static void buildConsequence( Rule rule, Class< ? > ruleClass, Object pojo )
|
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| throws DroolsException |
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| { |
78 |
14
| Consequence consequence = null;
|
79 |
14
| for (Method method : ruleClass.getMethods( ))
|
80 |
| { |
81 |
124
| DroolsConsequence consequenceAnnotation = method
|
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| .getAnnotation( DroolsConsequence.class ); |
83 |
124
| if (consequenceAnnotation != null)
|
84 |
| { |
85 |
14
| if (consequence != null)
|
86 |
| { |
87 |
1
| throw new DroolsException( "Rule must only contain one consequence method"
|
88 |
| + ": class = " + ruleClass + ", method = " + method ); |
89 |
| } |
90 |
13
| consequence = newPojoConsequence( rule, pojo, method );
|
91 |
10
| rule.setConsequence( consequence );
|
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| } |
93 |
| } |
94 |
10
| if (consequence == null)
|
95 |
| { |
96 |
1
| throw new DroolsException( "Rule must define a consequence method" + ": class = "
|
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| + ruleClass ); |
98 |
| } |
99 |
| } |
100 |
| |
101 |
14
| private static PojoCondition newPojoCondition( Rule rule, Object pojo, Method pojoMethod )
|
102 |
| throws DroolsException |
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| { |
104 |
14
| assertReturnType( pojoMethod, boolean.class );
|
105 |
13
| ParameterValidator parameterValidator = new ParameterValidator( ) {
|
106 |
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| public void assertParameter( ParameterValue newParameterValue,
|
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| List<ParameterValue> parameterValues ) |
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| throws DroolsException |
109 |
| { |
110 |
16
| if (newParameterValue instanceof KnowledgeHelperParameterValue)
|
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| { |
112 |
1
| throw new DroolsException(
|
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| "Condition methods cannot declare a parameter of type KnowledgeHelper" ); |
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| } |
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| } |
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| }; |
117 |
13
| return new PojoCondition( new RuleReflectMethod( rule, pojo, pojoMethod,
|
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| getParameterValues( rule, pojoMethod, parameterValidator ) ) ); |
119 |
| } |
120 |
| |
121 |
13
| private static PojoConsequence newPojoConsequence( Rule rule, Object pojo, Method pojoMethod )
|
122 |
| throws DroolsException |
123 |
| { |
124 |
13
| assertReturnType( pojoMethod, void.class );
|
125 |
12
| ParameterValidator parameterValidator = new ParameterValidator( ) {
|
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| private boolean hasDroolsParameterValue; |
127 |
| |
128 |
18
| public void assertParameter( ParameterValue newParameterValue,
|
129 |
| List<ParameterValue> parameterValues ) |
130 |
| throws DroolsException |
131 |
| { |
132 |
18
| if (newParameterValue instanceof KnowledgeHelperParameterValue)
|
133 |
| { |
134 |
9
| if (hasDroolsParameterValue)
|
135 |
| { |
136 |
1
| throw new DroolsException(
|
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| "Consequence methods can only declare on parameter of type Drools" ); |
138 |
| } |
139 |
8
| hasDroolsParameterValue = true;
|
140 |
| } |
141 |
| } |
142 |
| }; |
143 |
12
| return new PojoConsequence( new RuleReflectMethod( rule, pojo, pojoMethod,
|
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| getParameterValues( rule, pojoMethod, parameterValidator ) ) ); |
145 |
| } |
146 |
| |
147 |
27
| private static void assertReturnType( Method method, Class returnClass ) throws DroolsException
|
148 |
| { |
149 |
27
| if (method.getReturnType( ) != returnClass)
|
150 |
| { |
151 |
2
| throw new DroolsException( "Rule method returns the wrong class" + ": method = "
|
152 |
| + method + ", expected return class = " + returnClass |
153 |
| + ", actual return class = " + method.getReturnType( ) ); |
154 |
| } |
155 |
| } |
156 |
| |
157 |
25
| private static ParameterValue[] getParameterValues( Rule rule, Method method,
|
158 |
| ParameterValidator validator ) |
159 |
| throws DroolsException |
160 |
| { |
161 |
25
| Class< ? >[] parameterClasses = method.getParameterTypes( );
|
162 |
25
| Annotation[][] parameterAnnotations = method.getParameterAnnotations( );
|
163 |
25
| List<ParameterValue> parameterValues = new ArrayList<ParameterValue>( );
|
164 |
| |
165 |
25
| for (int i = 0; i < parameterClasses.length; i++)
|
166 |
| { |
167 |
36
| Class< ? > parameterClass = parameterClasses[i];
|
168 |
36
| ParameterValue parameterValue = null;
|
169 |
36
| try
|
170 |
| { |
171 |
36
| parameterValue = getParameterValue( rule, parameterClass, parameterAnnotations[i] );
|
172 |
34
| validator.assertParameter( parameterValue, parameterValues );
|
173 |
| } |
174 |
| catch (DroolsException e) |
175 |
| { |
176 |
4
| throwContextDroolsException( method, i, parameterClass, e );
|
177 |
| } |
178 |
32
| parameterValues.add( parameterValue );
|
179 |
| } |
180 |
21
| return parameterValues.toArray( new ParameterValue[parameterValues.size( )] );
|
181 |
| } |
182 |
| |
183 |
| |
184 |
| public interface ParameterValueFactory |
185 |
| { |
186 |
| Class<? extends ParameterValue> getParameterValueType(); |
187 |
| |
188 |
| ParameterValue create ( Rule rule, Class< ? > parameterClass, |
189 |
| Annotation[] parameterAnnotations) throws DroolsException; |
190 |
| } |
191 |
| |
192 |
| public static abstract class AnnotationParameterValueFactory implements ParameterValueFactory |
193 |
| { |
194 |
| private final Class<? extends Annotation> annotationClass; |
195 |
| |
196 |
8
| protected AnnotationParameterValueFactory(Class<? extends Annotation> annotationClass) {
|
197 |
8
| this.annotationClass = annotationClass;
|
198 |
| } |
199 |
| |
200 |
| protected abstract ParameterValue doCreate( Rule rule, |
201 |
| Class< ? > parameterClass, |
202 |
| Annotation annotation) throws InvalidRuleException; |
203 |
| |
204 |
43
| public ParameterValue create ( Rule rule, Class< ? > parameterClass,
|
205 |
| Annotation[] parameterAnnotations) throws DroolsException { |
206 |
43
| Annotation annotation = getAnnotation(annotationClass, parameterAnnotations);
|
207 |
43
| if (annotation == null) {
|
208 |
19
| return null;
|
209 |
| } |
210 |
24
| return doCreate(rule, parameterClass, annotation);
|
211 |
| } |
212 |
| |
213 |
43
| private Annotation getAnnotation(Class<? extends Annotation> annotationClass, Annotation[] parameterAnnotations) {
|
214 |
43
| for (Annotation annotation : parameterAnnotations) {
|
215 |
39
| if (annotationClass.isAssignableFrom(annotation.getClass())) {
|
216 |
24
| return annotation;
|
217 |
| } |
218 |
| } |
219 |
19
| return null;
|
220 |
| } |
221 |
| } |
222 |
| |
223 |
| public static class KnowledgeHelperParameterValueFactory implements ParameterValueFactory |
224 |
| { |
225 |
8
| public Class<? extends ParameterValue> getParameterValueType() {
|
226 |
8
| return KnowledgeHelperParameterValue.class;
|
227 |
| } |
228 |
| |
229 |
30
| public ParameterValue create ( Rule rule, Class< ? > parameterClass,
|
230 |
| Annotation[] parameterAnnotations) { |
231 |
30
| if (parameterClass != KnowledgeHelper.class) {
|
232 |
20
| return null;
|
233 |
| } |
234 |
10
| return new KnowledgeHelperParameterValue( rule );
|
235 |
| } |
236 |
| } |
237 |
| |
238 |
| public static class DroolsTupleParameterValueFactory extends AnnotationParameterValueFactory |
239 |
| { |
240 |
4
| public DroolsTupleParameterValueFactory() {
|
241 |
4
| super(DroolsParameter.class);
|
242 |
| } |
243 |
| |
244 |
8
| public Class<? extends ParameterValue> getParameterValueType() {
|
245 |
8
| return TupleParameterValue.class;
|
246 |
| } |
247 |
| |
248 |
21
| @Override
|
249 |
| public ParameterValue doCreate ( Rule rule, Class< ? > parameterClass, |
250 |
| Annotation annotation) throws InvalidRuleException { |
251 |
21
| String parameterId = ((DroolsParameter) annotation).value( );
|
252 |
21
| Declaration declaration = rule.getParameterDeclaration( parameterId );
|
253 |
21
| if (declaration == null)
|
254 |
| { |
255 |
11
| ClassObjectType classObjectType = new ClassObjectType( parameterClass );
|
256 |
11
| declaration = rule.addParameterDeclaration( parameterId, classObjectType );
|
257 |
| } |
258 |
21
| return new TupleParameterValue( declaration );
|
259 |
| } |
260 |
| } |
261 |
| |
262 |
| public static class DroolsApplicationDataParameterValueFactory extends AnnotationParameterValueFactory |
263 |
| { |
264 |
4
| public DroolsApplicationDataParameterValueFactory() {
|
265 |
4
| super(DroolsApplicationData.class);
|
266 |
| } |
267 |
| |
268 |
8
| public Class<? extends ParameterValue> getParameterValueType() {
|
269 |
8
| return ApplicationDataParameterValue.class;
|
270 |
| } |
271 |
| |
272 |
3
| @Override
|
273 |
| public ParameterValue doCreate ( Rule rule, Class< ? > parameterClass, |
274 |
| Annotation annotation) { |
275 |
3
| String parameterId = ((DroolsApplicationData) annotation).value( );
|
276 |
3
| return new ApplicationDataParameterValue( parameterId, parameterClass );
|
277 |
| } |
278 |
| } |
279 |
| |
280 |
36
| private static ParameterValue getParameterValue( Rule rule, Class< ? > parameterClass,
|
281 |
| Annotation[] parameterAnnotations ) |
282 |
| throws DroolsException |
283 |
| { |
284 |
36
| ParameterValue parameterValue;
|
285 |
36
| for (ParameterValueFactory factory : parameterValueFatories) {
|
286 |
73
| parameterValue = factory.create(rule, parameterClass, parameterAnnotations);
|
287 |
73
| if (parameterValue != null) {
|
288 |
34
| return parameterValue;
|
289 |
| } |
290 |
| } |
291 |
2
| throw new DroolsException(
|
292 |
| "Method parameter type not recognized or not annotated" ); |
293 |
| } |
294 |
| |
295 |
4
| private static void throwContextDroolsException( Method method, int i,
|
296 |
| Class< ? > parameterClass, Exception e ) |
297 |
| throws DroolsException |
298 |
| { |
299 |
4
| throw new DroolsException( e.getMessage( ) + ": method = " + method + ", parameter[" + i
|
300 |
| + "] = " + parameterClass, e ); |
301 |
| } |
302 |
| |
303 |
0
| private static void assertNonConflictingParameterAnnotation( ParameterValue parameterValue )
|
304 |
| throws DroolsException |
305 |
| { |
306 |
0
| if (parameterValue != null)
|
307 |
| { |
308 |
0
| throw new DroolsException( "Method parameter contains conflicting @Drools annotations" );
|
309 |
| } |
310 |
| } |
311 |
| } |