001    /**
002     *   GRANITE DATA SERVICES
003     *   Copyright (C) 2006-2013 GRANITE DATA SERVICES S.A.S.
004     *
005     *   This file is part of the Granite Data Services Platform.
006     *
007     *   Granite Data Services is free software; you can redistribute it and/or
008     *   modify it under the terms of the GNU Lesser General Public
009     *   License as published by the Free Software Foundation; either
010     *   version 2.1 of the License, or (at your option) any later version.
011     *
012     *   Granite Data Services is distributed in the hope that it will be useful,
013     *   but WITHOUT ANY WARRANTY; without even the implied warranty of
014     *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser
015     *   General Public License for more details.
016     *
017     *   You should have received a copy of the GNU Lesser General Public
018     *   License along with this library; if not, write to the Free Software
019     *   Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,
020     *   USA, or see <http://www.gnu.org/licenses/>.
021     */
022    
023    package org.granite.util;
024    
025    import java.lang.annotation.Annotation;
026    import java.lang.reflect.AnnotatedElement;
027    import java.lang.reflect.Array;
028    import java.lang.reflect.Constructor;
029    import java.lang.reflect.Field;
030    import java.lang.reflect.GenericArrayType;
031    import java.lang.reflect.InvocationTargetException;
032    import java.lang.reflect.Member;
033    import java.lang.reflect.Method;
034    import java.lang.reflect.Modifier;
035    import java.lang.reflect.ParameterizedType;
036    import java.lang.reflect.Type;
037    import java.lang.reflect.TypeVariable;
038    import java.lang.reflect.WildcardType;
039    import java.net.MalformedURLException;
040    import java.net.URL;
041    import java.util.ArrayList;
042    import java.util.Collections;
043    import java.util.HashMap;
044    import java.util.List;
045    import java.util.Map;
046    import java.util.Map.Entry;
047    import java.util.Set;
048    
049    /**
050     * @author Franck WOLFF
051     */
052    public abstract class ClassUtil {
053    
054        public static Object newInstance(String type)
055            throws ClassNotFoundException, InstantiationException, IllegalAccessException {
056            return forName(type).newInstance();
057        }
058    
059        public static <T> T newInstance(String type, Class<T> cast)
060            throws ClassNotFoundException, InstantiationException, IllegalAccessException {
061            return forName(type, cast).newInstance();
062        }
063    
064        public static Object newInstance(String type, Class<?>[] argsClass, Object[] argsValues)
065            throws ClassNotFoundException, InstantiationException, IllegalAccessException {
066            return newInstance(forName(type), argsClass, argsValues);
067        }
068    
069        @SuppressWarnings("unchecked")
070        public static <T> T newInstance(Class<?> type, Class<T> cast)
071            throws InstantiationException, IllegalAccessException {
072            return (T)type.newInstance();
073        }
074    
075        public static <T> T newInstance(Class<T> type, Class<?>[] argsClass, Object[] argsValues)
076            throws InstantiationException, IllegalAccessException {
077            T instance = null;
078            try {
079                Constructor<T> constructorDef = type.getConstructor(argsClass);
080                instance = constructorDef.newInstance(argsValues);
081            } catch (SecurityException e) {
082                throw new InstantiationException(e.getMessage());
083            } catch (NoSuchMethodException e) {
084                throw new InstantiationException(e.getMessage());
085            } catch (IllegalArgumentException e) {
086                throw new InstantiationException(e.getMessage());
087            } catch (InvocationTargetException e) {
088                throw new InstantiationException(e.getMessage());
089            }
090            return instance;
091        }
092    
093        public static Class<?> forName(String type) throws ClassNotFoundException {
094            try {
095                    return ClassUtil.class.getClassLoader().loadClass(type);
096            }
097            catch (ClassNotFoundException e) {
098                    return Thread.currentThread().getContextClassLoader().loadClass(type);
099            }
100        }
101    
102        @SuppressWarnings("unchecked")
103        public static <T> Class<T> forName(String type, Class<T> cast) throws ClassNotFoundException {
104            try {
105                    return (Class<T>)ClassUtil.class.getClassLoader().loadClass(type);
106            }
107            catch (ClassNotFoundException e) {
108                    return (Class<T>)Thread.currentThread().getContextClassLoader().loadClass(type);
109            }
110        }
111    
112        public static Constructor<?> getConstructor(String type, Class<?>[] paramTypes)
113            throws ClassNotFoundException, NoSuchMethodException {
114            return getConstructor(forName(type), paramTypes);
115        }
116    
117        public static <T> Constructor<T> getConstructor(Class<T> type, Class<?>[] paramTypes)
118            throws NoSuchMethodException {
119            return type.getConstructor(paramTypes);
120        }
121    
122        public static <T> List<T> emptyList(Class<T> type) {
123            return Collections.emptyList();
124        }
125    
126        public static <T> Set<T> emptySet(Class<T> type) {
127            return Collections.emptySet();
128        }
129    
130        public static <T, U> Map<T, U> emptyMap(Class<T> keyType, Class<U> valueType) {
131            return Collections.emptyMap();
132        }
133    
134        public static boolean isPrimitive(Type type) {
135            return type instanceof Class<?> && ((Class<?>)type).isPrimitive();
136        }
137    
138        public static Class<?> classOfType(Type type) {
139            if (type instanceof Class<?>)
140                return (Class<?>)type;
141            if (type instanceof ParameterizedType)
142                return (Class<?>)((ParameterizedType)type).getRawType();
143            if (type instanceof WildcardType) {
144                // Forget lower bounds and only deal with first upper bound...
145                Type[] ubs = ((WildcardType)type).getUpperBounds();
146                if (ubs.length > 0)
147                    return classOfType(ubs[0]);
148            }
149            if (type instanceof GenericArrayType) {
150                Class<?> ct = classOfType(((GenericArrayType)type).getGenericComponentType());
151                return (ct != null ? Array.newInstance(ct, 0).getClass() : Object[].class);
152            }
153            if (type instanceof TypeVariable<?>) {
154                // Only deal with first (upper) bound...
155                Type[] ubs = ((TypeVariable<?>)type).getBounds();
156                if (ubs.length > 0)
157                    return classOfType(ubs[0]);
158            }
159            // Should never happen...
160            return Object.class;
161        }
162        
163        public static Type getBoundType(TypeVariable<?> typeVariable) {
164            Type[] ubs = typeVariable.getBounds();
165            if (ubs.length > 0)
166                    return ubs[0];
167            
168            // should never happen...
169            if (typeVariable.getGenericDeclaration() instanceof Type)
170                    return (Type)typeVariable.getGenericDeclaration();
171            return typeVariable;
172        }
173    
174        public static String getPackageName(Class<?> clazz) {
175            return clazz.getPackage() != null ? clazz.getPackage().getName() : "";
176        }
177        
178        public static PropertyDescriptor[] getProperties(Class<?> clazz) {
179            try {
180                    PropertyDescriptor[] properties = new BeanInfo(clazz).getPropertyDescriptors();
181                    Field[] fields = clazz.getDeclaredFields();
182                    for (Field field : fields) {
183                            if (Boolean.class.equals(field.getType())) {
184                                    boolean found = false;
185                                    for (PropertyDescriptor property : properties) {
186                                            if (property.getName().equals(field.getName())) {
187                                                    found = true;
188                                                    if (property.getReadMethod() == null) {
189                                                            try {
190                                                                    Method readMethod = clazz.getDeclaredMethod(getIsMethodName(field.getName()));
191                                                                    if (Modifier.isPublic(readMethod.getModifiers()) && !Modifier.isStatic(readMethod.getModifiers()))
192                                                                            property.setReadMethod(readMethod);
193                                                            }
194                                                            catch (NoSuchMethodException e) {
195                                                            }
196                                                    }
197                                                    break;
198                                            }
199                                    }
200                                    if (!found) {
201                                                    try {
202                                                            Method readMethod = clazz.getDeclaredMethod(getIsMethodName(field.getName()));
203                                                            if (Modifier.isPublic(readMethod.getModifiers()) && !Modifier.isStatic(readMethod.getModifiers())) {
204                                                                    PropertyDescriptor[] propertiesTmp = new PropertyDescriptor[properties.length + 1];
205                                                                    System.arraycopy(properties, 0, propertiesTmp, 0, properties.length);
206                                                                    propertiesTmp[properties.length] = new PropertyDescriptor(field.getName(), readMethod, null);
207                                                                    properties = propertiesTmp;
208                                                            }
209                                                    }
210                                                    catch (NoSuchMethodException e) {
211                                                    }
212                                    }
213                            }
214                    }
215                return properties;
216            } catch (Exception e) {
217                throw new RuntimeException("Could not introspect properties of class: " + clazz, e);
218            }
219        }
220        
221        private static String getIsMethodName(String name) {
222            return "is" + name.substring(0, 1).toUpperCase() + name.substring(1);
223        }
224       
225        public static ClassLoader getClassLoader(Class<?> clazz) {
226            return (clazz.getClassLoader() != null ? clazz.getClassLoader() : ClassLoader.getSystemClassLoader());
227        }
228    
229        public static URL findResource(Class<?> clazz) {
230            while (clazz.isArray())
231                clazz = clazz.getComponentType();
232            if (clazz.isPrimitive())
233                return null;
234            URL url = getClassLoader(clazz).getResource(toResourceName(clazz));
235            String path = url.toString();
236            if (path.indexOf(' ') != -1) {
237                    try {
238                                    url = new URL(path.replace(" ", "%20"));
239                            } catch (MalformedURLException e) {
240                                    // should never happen...
241                            }
242            }
243            return url;
244        }
245    
246        public static String toResourceName(Class<?> clazz) {
247            return clazz.getName().replace('.', '/').concat(".class");
248        }
249        
250        public static String getMethodSignature(Method method) {
251            StringBuilder sb = new StringBuilder();
252            sb.append(method.getName()).append('(');
253            Class<?>[] params = method.getParameterTypes();
254            for (int i = 0; i < params.length; i++) {
255                    if (i > 0)
256                            sb.append(',');
257                    sb.append(getTypeSignature(params[i]));
258            }
259            sb.append(')');
260            return sb.toString();
261        }
262            
263        public static String getTypeSignature(Class<?> type) {
264                    if (type.isArray()) {
265                        try {
266                                    int dimensions = 1;
267                                    Class<?> clazz = type.getComponentType();
268                                    while (clazz.isArray()) {
269                                            dimensions++;
270                                            clazz = clazz.getComponentType();
271                                    }
272                                    
273                                    StringBuffer sb = new StringBuffer(clazz.getName());
274                                    while (dimensions-- > 0)
275                                        sb.append("[]");
276                                    return sb.toString();
277                        } catch (Throwable e) {
278                            // fallback...
279                        }
280                    }
281                    return type.getName();
282            }
283        
284        public static Method getMethod(Class<?> clazz, String signature) throws NoSuchMethodException {
285            signature = removeSpaces(signature);
286                    
287            if (!signature.endsWith(")"))
288                            signature += "()";
289                    
290                    for (Method method : clazz.getMethods()) {
291                            if (signature.equals(getMethodSignature(method)))
292                                    return method;
293                    }
294                    
295                    throw new NoSuchMethodException("Could not find method: " + signature + " in class: " + clazz);
296        }
297            
298            public static String removeSpaces(String s) {
299                    if (s == null)
300                            return null;
301            String[] tokens = s.split("\\s", -1);
302            if (tokens.length == 0)
303                    return "";
304            if (tokens.length == 1)
305                    return tokens[0];
306            StringBuilder sb = new StringBuilder();
307            for (String token : tokens)
308                    sb.append(token);
309            return sb.toString();
310        }
311            
312        public static String decapitalize(String name) {
313    
314            if (name == null)
315                return null;
316            // The rule for decapitalize is that:
317            // If the first letter of the string is Upper Case, make it lower case
318            // UNLESS the second letter of the string is also Upper Case, in which case no
319            // changes are made.
320            if (name.length() == 0 || (name.length() > 1 && Character.isUpperCase(name.charAt(1)))) {
321                return name;
322            }
323            
324            char[] chars = name.toCharArray();
325            chars[0] = Character.toLowerCase(chars[0]);
326            return new String(chars);
327        }
328        
329        public static boolean isAnnotationPresent(AnnotatedElement elmt, Class<? extends Annotation> annotationClass) {
330            return getAnnotation(elmt, annotationClass) != null;
331        }
332        
333        public static <T extends Annotation> DeclaredAnnotation<T> getAnnotation(AnnotatedElement elmt, Class<T> annotationClass) {
334            T annotation = elmt.getAnnotation(annotationClass);
335            
336            if (annotation != null) {
337                    Class<?> declaringClass = (elmt instanceof Member ? ((Member)elmt).getDeclaringClass() : (Class<?>)elmt);
338                    return new DeclaredAnnotation<T>(annotation, elmt, declaringClass);
339            }
340            
341            if (elmt instanceof Field)
342                    return null;
343            
344            if (elmt instanceof Method) {
345                    Method m = (Method)elmt;
346                    return getMethodAnnotation(m.getDeclaringClass(), m.getName(), m.getParameterTypes(), annotationClass);
347            }
348            
349            if (elmt instanceof Constructor) {
350                    Constructor<?> c = (Constructor<?>)elmt;
351                    return getConstructorAnnotation(c.getDeclaringClass(), annotationClass);
352            }
353            
354            if (elmt instanceof Class) {
355                    Class<?> c = (Class<?>)elmt;
356                    return getClassAnnotation(c.getDeclaringClass(), annotationClass);
357            }
358            
359            throw new RuntimeException("Unsupported annotated element: " + elmt);
360        }
361        
362        public static <T extends Annotation> DeclaredAnnotation<T> getMethodAnnotation(Class<?> clazz, String name, Class<?>[] parameterTypes, Class<T> annotationClass) {
363            DeclaredAnnotation<T> declaredAnnotation = null;
364            
365            try {
366                    Method method = clazz.getDeclaredMethod(name, parameterTypes);
367                    T annotation = clazz.getDeclaredMethod(name, parameterTypes).getAnnotation(annotationClass);
368                    if (annotation != null)
369                            declaredAnnotation = new DeclaredAnnotation<T>(annotation, method, clazz);
370            }
371            catch (NoSuchMethodException e) {
372                    // fallback...
373            }
374            
375            if (declaredAnnotation == null && clazz.getSuperclass() != null)
376                    declaredAnnotation = getMethodAnnotation(clazz.getSuperclass(), name, parameterTypes, annotationClass);
377            
378            if (declaredAnnotation == null) {
379                    for (Class<?> interfaze : clazz.getInterfaces()) {
380                            declaredAnnotation = getMethodAnnotation(interfaze, name, parameterTypes, annotationClass);
381                            if (declaredAnnotation != null)
382                                    break;
383                    }
384            }
385                    
386            return declaredAnnotation;
387        }
388        
389        public static <T extends Annotation> DeclaredAnnotation<T> getConstructorAnnotation(Class<?> clazz, Class<T> annotationClass) {
390            DeclaredAnnotation<T> declaredAnnotation = null;
391            
392            for (Constructor<?> constructor : clazz.getDeclaredConstructors()) {
393                    T annotation = constructor.getAnnotation(annotationClass);
394                    if (annotation != null) {
395                            declaredAnnotation = new DeclaredAnnotation<T>(annotation, constructor, clazz);
396                            break;
397                    }
398            }
399            
400            if (declaredAnnotation == null && clazz.getSuperclass() != null)
401                    declaredAnnotation = getConstructorAnnotation(clazz.getSuperclass(), annotationClass);
402                    
403            return declaredAnnotation;
404        }
405        
406        public static <T extends Annotation> DeclaredAnnotation<T> getClassAnnotation(Class<?> clazz, Class<T> annotationClass) {
407            DeclaredAnnotation<T> declaredAnnotation = null;
408            
409            T annotation = clazz.getAnnotation(annotationClass);
410            if (annotation != null)
411                    declaredAnnotation = new DeclaredAnnotation<T>(annotation, clazz, clazz);
412            else {
413                    if (clazz.getSuperclass() != null)
414                            declaredAnnotation = getClassAnnotation(clazz.getSuperclass(), annotationClass);
415                    
416                    if (declaredAnnotation == null) {
417                            for (Class<?> interfaze : clazz.getInterfaces()) {
418                                    declaredAnnotation = getClassAnnotation(interfaze, annotationClass);
419                                    if (declaredAnnotation != null)
420                                            break;
421                            }
422                    }
423            }
424                    
425            return declaredAnnotation;
426        }
427        
428        public static class DeclaredAnnotation<T extends Annotation> {
429    
430            public final T annotation;
431            public final AnnotatedElement annotatedElement;
432            public final Class<?> declaringClass;
433                    
434            public DeclaredAnnotation(T annotation, AnnotatedElement annotatedElement, Class<?> declaringClass) {
435                            this.annotation = annotation;
436                            this.annotatedElement = annotatedElement;
437                            this.declaringClass = declaringClass;
438                    }
439    
440                    @Override
441                    public String toString() {
442                            return getClass().getName() + "{annotation=" + annotation + ", annotatedElement=" + annotatedElement + ", declaringClass=" + declaringClass + "}";
443                    }
444        }
445        
446        
447        private static class BeanInfo {
448    
449            private Class<?> beanClass;
450            private PropertyDescriptor[] properties = null;
451    
452            
453            public BeanInfo(Class<?> beanClass) {
454                this.beanClass = beanClass;
455    
456                if (properties == null)
457                    properties = introspectProperties();
458            }
459    
460            public PropertyDescriptor[] getPropertyDescriptors() {
461                return properties;
462            }
463    
464            /**
465             * Introspects the supplied class and returns a list of the Properties of
466             * the class
467             * 
468             * @return The list of Properties as an array of PropertyDescriptors
469             */
470            private PropertyDescriptor[] introspectProperties() {
471    
472                    Method[] methods = beanClass.getMethods();
473                    List<Method> methodList = new ArrayList<Method>();
474                    
475                    for (Method method : methods) {
476                            if (!Modifier.isPublic(method.getModifiers()) || Modifier.isStatic(method.getModifiers()))
477                                    continue;
478                            methodList.add(method);
479                    }
480    
481                Map<String, Map<String, Object>> propertyMap = new HashMap<String, Map<String, Object>>(methodList.size());
482    
483                // Search for methods that either get or set a Property
484                for (Method method : methodList) {
485                    introspectGet(method, propertyMap);
486                    introspectSet(method, propertyMap);
487                }
488    
489                // fix possible getter & setter collisions
490                fixGetSet(propertyMap);
491                
492                // Put the properties found into the PropertyDescriptor array
493                List<PropertyDescriptor> propertyList = new ArrayList<PropertyDescriptor>();
494    
495                for (Map.Entry<String, Map<String, Object>> entry : propertyMap.entrySet()) {
496                    String propertyName = entry.getKey();
497                    Map<String, Object> table = entry.getValue();
498                    if (table == null)
499                        continue;
500                    
501                    Method getter = (Method)table.get("getter");
502                    Method setter = (Method)table.get("setter");
503    
504                    PropertyDescriptor propertyDesc = new PropertyDescriptor(propertyName, getter, setter);
505                    propertyList.add(propertyDesc);
506                }
507    
508                PropertyDescriptor[] properties = new PropertyDescriptor[propertyList.size()];
509                propertyList.toArray(properties);
510                return properties;
511            }
512    
513            @SuppressWarnings("unchecked")
514            private static void introspectGet(Method method, Map<String, Map<String, Object>> propertyMap) {
515                String methodName = method.getName();
516                
517                if (!(method.getName().startsWith("get") || method.getName().startsWith("is")))
518                    return;
519                
520                if (method.getParameterTypes().length > 0 || method.getReturnType() == void.class)
521                    return;
522                
523                if (method.getName().startsWith("is") && method.getReturnType() != boolean.class)
524                    return;
525    
526                String propertyName = method.getName().startsWith("get") ? methodName.substring(3) : methodName.substring(2);
527                propertyName = decapitalize(propertyName);
528    
529                Map<String, Object> table = propertyMap.get(propertyName);
530                if (table == null) {
531                    table = new HashMap<String, Object>();
532                    propertyMap.put(propertyName, table);
533                }
534    
535                List<Method> getters = (List<Method>)table.get("getters");
536                if (getters == null) {
537                    getters = new ArrayList<Method>();
538                    table.put("getters", getters);
539                }
540                getters.add(method);
541            }
542    
543            @SuppressWarnings("unchecked")
544            private static void introspectSet(Method method, Map<String, Map<String, Object>> propertyMap) {
545                String methodName = method.getName();
546                
547                if (!method.getName().startsWith("set"))
548                    return;
549                
550                if (method.getParameterTypes().length != 1 || method.getReturnType() != void.class)
551                    return;
552    
553                String propertyName = decapitalize(methodName.substring(3));
554    
555                Map<String, Object> table = propertyMap.get(propertyName);
556                if (table == null) {
557                    table = new HashMap<String, Object>();
558                    propertyMap.put(propertyName, table);
559                }
560    
561                List<Method> setters = (List<Method>)table.get("setters");
562                if (setters == null) {
563                    setters = new ArrayList<Method>();
564                    table.put("setters", setters);
565                }
566    
567                // add new setter
568                setters.add(method);
569            }
570    
571            /**
572             * Checks and fixs all cases when several incompatible checkers / getters
573             * were specified for single property.
574             * 
575             * @param propertyMap
576             */
577            private void fixGetSet(Map<String, Map<String, Object>> propertyMap) {
578                if (propertyMap == null)
579                    return;
580    
581                for (Entry<String, Map<String, Object>> entry : propertyMap.entrySet()) {
582                    Map<String, Object> table = entry.getValue();
583                    @SuppressWarnings("unchecked")
584                                    List<Method> getters = (List<Method>)table.get("getters");
585                    @SuppressWarnings("unchecked")
586                                    List<Method> setters = (List<Method>)table.get("setters");
587                    if (getters == null)
588                        getters = new ArrayList<Method>();
589                    if (setters == null)
590                        setters = new ArrayList<Method>();
591    
592                    Method definedGetter = getters.isEmpty() ? null : getters.get(0);
593                    Method definedSetter = null;
594    
595                    if (definedGetter != null) {
596                        Class<?> propertyType = definedGetter.getReturnType();
597            
598                        for (Method setter : setters) {
599                            if (setter.getParameterTypes().length == 1 && propertyType.equals(setter.getParameterTypes()[0])) {
600                                definedSetter = setter;
601                                break;
602                            }
603                        }
604                        if (definedSetter != null && !setters.isEmpty())
605                            definedSetter = setters.get(0);
606                    } 
607                    else if (!setters.isEmpty()) {
608                            definedSetter = setters.get(0);
609                    }
610    
611                    table.put("getter", definedGetter);
612                    table.put("setter", definedSetter);
613                }
614            }
615        }
616    
617    }