001    /**
002     * Licensed to the Apache Software Foundation (ASF) under one or more
003     * contributor license agreements.  See the NOTICE file distributed with
004     * this work for additional information regarding copyright ownership.
005     * The ASF licenses this file to You under the Apache License, Version 2.0
006     * (the "License"); you may not use this file except in compliance with
007     * the License.  You may obtain a copy of the License at
008     *
009     *      http://www.apache.org/licenses/LICENSE-2.0
010     *
011     * Unless required by applicable law or agreed to in writing, software
012     * distributed under the License is distributed on an "AS IS" BASIS,
013     * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014     * See the License for the specific language governing permissions and
015     * limitations under the License.
016     */
017    package org.apache.camel.util;
018    
019    import java.io.Closeable;
020    import java.io.File;
021    import java.io.FileNotFoundException;
022    import java.io.IOException;
023    import java.io.InputStream;
024    import java.lang.annotation.Annotation;
025    import java.lang.reflect.AnnotatedElement;
026    import java.lang.reflect.InvocationTargetException;
027    import java.lang.reflect.Method;
028    import java.nio.channels.ReadableByteChannel;
029    import java.nio.charset.Charset;
030    import java.util.ArrayList;
031    import java.util.Arrays;
032    import java.util.Collection;
033    import java.util.Collections;
034    import java.util.Iterator;
035    import java.util.List;
036    import java.util.Scanner;
037    
038    import org.w3c.dom.Node;
039    import org.w3c.dom.NodeList;
040    
041    import org.apache.camel.CamelExecutionException;
042    import org.apache.camel.Exchange;
043    import org.apache.camel.RuntimeCamelException;
044    import org.apache.camel.TypeConverter;
045    import org.apache.camel.component.file.GenericFile;
046    import org.apache.commons.logging.Log;
047    import org.apache.commons.logging.LogFactory;
048    
049    /**
050     * A number of useful helper methods for working with Objects
051     *
052     * @version $Revision: 793935 $
053     */
054    public final class ObjectHelper {
055        private static final transient Log LOG = LogFactory.getLog(ObjectHelper.class);
056    
057        /**
058         * Utility classes should not have a public constructor.
059         */
060        private ObjectHelper() {
061        }
062    
063        /**
064         * A helper method for comparing objects for equality in which it uses type coerce to coerce
065         * types between the left and right values. This allows you to equal test eg String and Integer as
066         * Camel will be able to coerce the types
067         */
068        public static boolean typeCoerceEquals(TypeConverter converter, Object leftValue, Object rightValue) {
069            // try without type coerce
070            boolean answer = equal(leftValue, rightValue);
071            if (answer) {
072                return true;
073            }
074    
075            if (leftValue == null || rightValue == null) {
076                // no reason to continue as the first equal did not match and now one of the values is null
077                // so it wont help to type coerece to a null type
078                return false;
079            }
080    
081            // convert left to right
082            Object value = converter.convertTo(rightValue.getClass(), leftValue);
083            answer = equal(value, rightValue);
084            if (answer) {
085                return true;
086            }
087    
088            // convert right to left
089            value = converter.convertTo(leftValue.getClass(), rightValue);
090            answer = equal(leftValue, value);
091            return answer;
092        }
093    
094        /**
095         * A helper method for comparing objects for equality in which it uses type coerce to coerce
096         * types between the left and right values. This allows you to equal test eg String and Integer as
097         * Camel will be able to coerce the types
098         */
099        public static boolean typeCoerceNotEquals(TypeConverter converter, Object leftValue, Object rightValue) {
100            return !typeCoerceEquals(converter, leftValue, rightValue);
101        }
102    
103        /**
104         * A helper method for comparing objects ordering in which it uses type coerce to coerce
105         * types between the left and right values. This allows you to equal test eg String and Integer as
106         * Camel will be able to coerce the types
107         */
108        @SuppressWarnings("unchecked")
109        public static int typeCoerceCompare(TypeConverter converter, Object leftValue, Object rightValue) {
110            if (rightValue instanceof Comparable) {
111                Object value = converter.convertTo(rightValue.getClass(), leftValue);
112                if (value != null) {
113                    return ((Comparable) rightValue).compareTo(value) * -1;
114                }
115            }
116    
117            if (leftValue instanceof Comparable) {
118                Object value = converter.convertTo(leftValue.getClass(), rightValue);
119                if (value != null) {
120                    return ((Comparable) leftValue).compareTo(value);
121                }
122            }
123    
124            // use regular compare
125            return compare(leftValue, rightValue);
126        }
127    
128        /**
129         * A helper method for comparing objects for equality while handling nulls
130         */
131        public static boolean equal(Object a, Object b) {
132            if (a == b) {
133                return true;
134            }
135    
136            if (a instanceof byte[] && b instanceof byte[]) {
137                return equalByteArray((byte[])a, (byte[])b);
138            }
139    
140            return a != null && b != null && a.equals(b);
141        }
142    
143        /**
144         * A helper method for comparing byte arrays for equality while handling
145         * nulls
146         */
147        public static boolean equalByteArray(byte[] a, byte[] b) {
148            if (a == b) {
149                return true;
150            }
151    
152            // loop and compare each byte
153            if (a != null && b != null && a.length == b.length) {
154                for (int i = 0; i < a.length; i++) {
155                    if (a[i] != b[i]) {
156                        return false;
157                    }
158                }
159                // all bytes are equal
160                return true;
161            }
162    
163            return false;
164        }
165    
166        /**
167         * Returns true if the given object is equal to any of the expected value
168         */
169        public static boolean isEqualToAny(Object object, Object... values) {
170            for (Object value : values) {
171                if (equal(object, value)) {
172                    return true;
173                }
174            }
175            return false;
176        }
177    
178        /**
179         * A helper method for performing an ordered comparison on the objects
180         * handling nulls and objects which do not handle sorting gracefully
181         */
182        public static int compare(Object a, Object b) {
183            return compare(a, b, false);
184        }
185    
186        /**
187         * A helper method for performing an ordered comparison on the objects
188         * handling nulls and objects which do not handle sorting gracefully
189         *
190         * @param a  the first object
191         * @param b  the second object
192         * @param ignoreCase  ignore case for string comparison
193         */
194        @SuppressWarnings("unchecked")
195        public static int compare(Object a, Object b, boolean ignoreCase) {
196            if (a == b) {
197                return 0;
198            }
199            if (a == null) {
200                return -1;
201            }
202            if (b == null) {
203                return 1;
204            }
205            if (ignoreCase && a instanceof String && b instanceof String) {
206                return ((String) a).compareToIgnoreCase((String) b);
207            }
208            if (a instanceof Comparable) {
209                Comparable comparable = (Comparable)a;
210                return comparable.compareTo(b);
211            } else {
212                int answer = a.getClass().getName().compareTo(b.getClass().getName());
213                if (answer == 0) {
214                    answer = a.hashCode() - b.hashCode();
215                }
216                return answer;
217            }
218        }
219    
220        public static Boolean toBoolean(Object value) {
221            if (value instanceof Boolean) {
222                return (Boolean)value;
223            }
224            if (value instanceof String) {
225                return "true".equalsIgnoreCase(value.toString()) ? Boolean.TRUE : Boolean.FALSE;
226            }
227            if (value instanceof Integer) {
228                return (Integer)value > 0 ? Boolean.TRUE : Boolean.FALSE;
229            }
230            return null;
231        }
232    
233        /**
234         * Asserts whether the value is <b>not</b> <tt>null</tt>
235         *
236         * @param value  the value to test
237         * @param name   the key that resolved the value
238         * @throws IllegalArgumentException is thrown if assertion fails
239         */
240        public static void notNull(Object value, String name) {
241            if (value == null) {
242                throw new IllegalArgumentException(name + " must be specified");
243            }
244        }
245    
246        /**
247         * Asserts whether the value is <b>not</b> <tt>null</tt>
248         *
249         * @param value  the value to test
250         * @param on     additional description to indicate where this problem occured (appended as toString())
251         * @param name   the key that resolved the value
252         * @throws IllegalArgumentException is thrown if assertion fails
253         */
254        public static void notNull(Object value, String name, Object on) {
255            if (on == null) {
256                notNull(value, name);
257            } else if (value == null) {
258                throw new IllegalArgumentException(name + " must be specified on: " + on);
259            }
260        }
261    
262        /**
263         * Asserts whether the string is <b>not</b> empty.
264         *
265         * @param value  the string to test
266         * @param name   the key that resolved the value
267         * @throws IllegalArgumentException is thrown if assertion fails
268         */
269        public static void notEmpty(String value, String name) {
270            if (isEmpty(value)) {
271                throw new IllegalArgumentException(name + " must be specified and not empty");
272            }
273        }
274    
275        /**
276         * Asserts whether the string is <b>not</b> empty.
277         *
278         * @param value  the string to test
279         * @param on     additional description to indicate where this problem occured (appended as toString())
280         * @param name   the key that resolved the value
281         * @throws IllegalArgumentException is thrown if assertion fails
282         */
283        public static void notEmpty(String value, String name, Object on) {
284            if (on == null) {
285                notNull(value, name);
286            } else if (isEmpty(value)) {
287                throw new IllegalArgumentException(name + " must be specified and not empty on: " + on);
288            }
289        }
290    
291        /**
292         * Tests whether the value is <tt>null</tt> or an empty string.
293         *
294         * @param value  the value, if its a String it will be tested for text length as well
295         * @return true if empty
296         */
297        public static boolean isEmpty(Object value) {
298            return !isNotEmpty(value);
299        }
300    
301        /**
302         * Tests whether the value is <b>not</b> <tt>null</tt> or an empty string.
303         *
304         * @param value  the value, if its a String it will be tested for text length as well
305         * @return true if <b>not</b> empty
306         */
307        public static boolean isNotEmpty(Object value) {
308            if (value == null) {
309                return false;
310            } else if (value instanceof String) {
311                String text = (String) value;
312                return text.trim().length() > 0;
313            } else {
314                return true;
315            }
316        }
317    
318        public static String[] splitOnCharacter(String value, String needle, int count) {
319            String rc[] = new String[count];
320            rc[0] = value;
321            for (int i = 1; i < count; i++) {
322                String v = rc[i - 1];
323                int p = v.indexOf(needle);
324                if (p < 0) {
325                    return rc;
326                }
327                rc[i - 1] = v.substring(0, p);
328                rc[i] = v.substring(p + 1);
329            }
330            return rc;
331        }
332    
333        /**
334         * Removes any starting characters on the given text which match the given
335         * character
336         *
337         * @param text the string
338         * @param ch the initial characters to remove
339         * @return either the original string or the new substring
340         */
341        public static String removeStartingCharacters(String text, char ch) {
342            int idx = 0;
343            while (text.charAt(idx) == ch) {
344                idx++;
345            }
346            if (idx > 0) {
347                return text.substring(idx);
348            }
349            return text;
350        }
351    
352        public static String capitalize(String text) {
353            if (text == null) {
354                return null;
355            }
356            int length = text.length();
357            if (length == 0) {
358                return text;
359            }
360            String answer = text.substring(0, 1).toUpperCase();
361            if (length > 1) {
362                answer += text.substring(1, length);
363            }
364            return answer;
365        }
366    
367        public static String after(String text, String after) {
368            if (!text.contains(after)) {
369                return null;
370            }
371            return text.substring(text.indexOf(after) + after.length());
372        }
373    
374        public static String before(String text, String before) {
375            if (!text.contains(before)) {
376                return null;
377            }
378            return text.substring(0, text.indexOf(before));
379        }
380    
381        public static String between(String text, String after, String before) {
382            text = after(text, after);
383            if (text == null) {
384                return null;
385            }
386            return before(text, before);
387        }
388    
389        /**
390         * Returns true if the collection contains the specified value
391         */
392        @SuppressWarnings("unchecked")
393        public static boolean contains(Object collectionOrArray, Object value) {
394            if (collectionOrArray instanceof Collection) {
395                Collection collection = (Collection)collectionOrArray;
396                return collection.contains(value);
397            } else if (collectionOrArray instanceof String && value instanceof String) {
398                String str = (String)collectionOrArray;
399                String subStr = (String)value;
400                return str.contains(subStr);
401            } else {
402                Iterator iter = createIterator(collectionOrArray);
403                while (iter.hasNext()) {
404                    if (equal(value, iter.next())) {
405                        return true;
406                    }
407                }
408            }
409            return false;
410        }
411    
412        /**
413         * Creates an iterator over the value if the value is a collection, an
414         * Object[] or a primitive type array; otherwise to simplify the caller's
415         * code, we just create a singleton collection iterator over a single value
416         * <p/>
417         * Will default use comma for String separating String values.
418         *
419         * @param value  the value
420         * @return the iterator
421         */
422        public static Iterator createIterator(Object value) {
423            return createIterator(value, ",");
424        }
425    
426        /**
427         * Creates an iterator over the value if the value is a collection, an
428         * Object[] or a primitive type array; otherwise to simplify the caller's
429         * code, we just create a singleton collection iterator over a single value
430         *
431         * @param value  the value
432         * @param  delimiter  delimiter for separating String values
433         * @return the iterator
434         */
435        @SuppressWarnings("unchecked")
436        public static Iterator createIterator(Object value, String delimiter) {
437            if (value == null) {
438                return Collections.EMPTY_LIST.iterator();
439            } else if (value instanceof Iterator) {
440                return (Iterator)value;
441            } else if (value instanceof Collection) {
442                Collection collection = (Collection)value;
443                return collection.iterator();
444            } else if (value.getClass().isArray()) {
445                // TODO we should handle primitive array types?
446                List<Object> list = Arrays.asList((Object[])value);
447                return list.iterator();
448            } else if (value instanceof NodeList) {
449                // lets iterate through DOM results after performing XPaths
450                final NodeList nodeList = (NodeList)value;
451                return new Iterator<Node>() {
452                    int idx = -1;
453    
454                    public boolean hasNext() {
455                        return ++idx < nodeList.getLength();
456                    }
457    
458                    public Node next() {
459                        return nodeList.item(idx);
460                    }
461    
462                    public void remove() {
463                        throw new UnsupportedOperationException();
464                    }
465                };
466            } else if (value instanceof String) {
467                final String s = (String) value;
468    
469                // this code is optimized to only use a Scanner if needed, eg there is a delimiter
470    
471                if (s.contains(delimiter)) {
472                    // use a scanner if it contains the delimtor
473                    Scanner scanner = new Scanner((String)value);
474                    scanner.useDelimiter(delimiter);
475                    return scanner;
476                } else {
477                    // use a plain iterator that returns the value as is as there are only a single value
478                    return new Iterator<String>() {
479                        int idx = -1;
480    
481                        public boolean hasNext() {
482                            // empty string should not be regarded as having next
483                            return ++idx == 0 && ObjectHelper.isNotEmpty(s);
484                        }
485    
486                        public String next() {
487                            return s;
488                        }
489    
490                        public void remove() {
491                            throw new UnsupportedOperationException();
492                        }
493                    };
494                }
495            } else {
496                return Collections.singletonList(value).iterator();
497            }
498        }
499    
500        /**
501         * Returns the predicate matching boolean on a {@link List} result set where
502         * if the first element is a boolean its value is used otherwise this method
503         * returns true if the collection is not empty
504         *
505         * @return <tt>true</tt> if the first element is a boolean and its value
506         *         is true or if the list is non empty
507         */
508        public static boolean matches(List list) {
509            if (!list.isEmpty()) {
510                Object value = list.get(0);
511                if (value instanceof Boolean) {
512                    return (Boolean)value;
513                } else {
514                    // lets assume non-empty results are true
515                    return true;
516                }
517            }
518            return false;
519        }
520    
521        /**
522         * A helper method to access a system property, catching any security
523         * exceptions
524         *
525         * @param name the name of the system property required
526         * @param defaultValue the default value to use if the property is not
527         *                available or a security exception prevents access
528         * @return the system property value or the default value if the property is
529         *         not available or security does not allow its access
530         */
531        public static String getSystemProperty(String name, String defaultValue) {
532            try {
533                return System.getProperty(name, defaultValue);
534            } catch (Exception e) {
535                if (LOG.isDebugEnabled()) {
536                    LOG.debug("Caught security exception accessing system property: " + name + ". Reason: " + e, e);
537                }
538                return defaultValue;
539            }
540        }
541    
542        /**
543         * A helper method to access a boolean system property, catching any
544         * security exceptions
545         *
546         * @param name the name of the system property required
547         * @param defaultValue the default value to use if the property is not
548         *                available or a security exception prevents access
549         * @return the boolean representation of the system property value or the
550         *         default value if the property is not available or security does
551         *         not allow its access
552         */
553        public static boolean getSystemProperty(String name, Boolean defaultValue) {
554            String result = getSystemProperty(name, defaultValue.toString());
555            return Boolean.parseBoolean(result);
556        }
557    
558        /**
559         * Returns the type name of the given type or null if the type variable is
560         * null
561         */
562        public static String name(Class type) {
563            return type != null ? type.getName() : null;
564        }
565    
566        /**
567         * Returns the type name of the given value
568         */
569        public static String className(Object value) {
570            return name(value != null ? value.getClass() : null);
571        }
572    
573        /**
574         * Returns the canonical type name of the given value
575         */
576        public static String classCanonicalName(Object value) {
577            if (value != null) {
578                return value.getClass().getCanonicalName();
579            } else {
580                return null;
581            }
582        }
583    
584        /**
585         * Attempts to load the given class name using the thread context class
586         * loader or the class loader used to load this class
587         *
588         * @param name the name of the class to load
589         * @return the class or null if it could not be loaded
590         */
591        public static Class<?> loadClass(String name) {
592            return loadClass(name, ObjectHelper.class.getClassLoader());
593        }
594    
595        /**
596         * Attempts to load the given class name using the thread context class
597         * loader or the given class loader
598         *
599         * @param name the name of the class to load
600         * @param loader the class loader to use after the thread context class
601         *                loader
602         * @return the class or null if it could not be loaded
603         */
604        public static Class<?> loadClass(String name, ClassLoader loader) {
605            // must clean the name so its pure java name, eg remoing \n or whatever people can do in the Spring XML
606            name = normalizeClassName(name);
607    
608            // special for byte[] as its common to use
609            if ("java.lang.byte[]".equals(name) || "byte[]".equals(name)) {
610                return byte[].class;
611            }
612    
613            // try context class loader first
614            Class clazz = doLoadClass(name, Thread.currentThread().getContextClassLoader());
615            if (clazz == null) {
616                // then the provided loader
617                clazz = doLoadClass(name, loader);
618            }
619            if (clazz == null) {
620                // and fallback to the loader the loaded the ObjectHelper class
621                clazz = doLoadClass(name, ObjectHelper.class.getClassLoader());
622            }
623    
624            if (clazz == null) {
625                LOG.warn("Cannot find class: " + name);
626            }
627    
628            return clazz;
629        }
630    
631        /**
632         * Loads the given class with the provided classloader (may be null).
633         * Will ignore any class not found and return null.
634         *
635         * @param name    the name of the class to load
636         * @param loader  a provided loader (may be null)
637         * @return the class, or null if it could not be loaded
638         */
639        private static Class<?> doLoadClass(String name, ClassLoader loader) {
640            ObjectHelper.notEmpty(name, "name");
641            if (loader == null) {
642                return null;
643            }
644            try {
645                if (LOG.isTraceEnabled()) {
646                    LOG.trace("Loading class: " + name + " using classloader: " + loader);
647                }
648                return loader.loadClass(name);
649            } catch (ClassNotFoundException e) {
650                if (LOG.isTraceEnabled()) {
651                    LOG.trace("Cannot load class: " + name + " using classloader: " + loader, e);
652                }
653    
654            }
655            return null;
656        }
657    
658        /**
659         * Attempts to load the given resource as a stream using the thread context
660         * class loader or the class loader used to load this class
661         *
662         * @param name the name of the resource to load
663         * @return the stream or null if it could not be loaded
664         */
665        public static InputStream loadResourceAsStream(String name) {
666            InputStream in = null;
667    
668            ClassLoader contextClassLoader = Thread.currentThread().getContextClassLoader();
669            if (contextClassLoader != null) {
670                in = contextClassLoader.getResourceAsStream(name);
671            }
672            if (in == null) {
673                in = ObjectHelper.class.getClassLoader().getResourceAsStream(name);
674            }
675    
676            return in;
677        }
678    
679        /**
680         * A helper method to invoke a method via reflection and wrap any exceptions
681         * as {@link RuntimeCamelException} instances
682         *
683         * @param method the method to invoke
684         * @param instance the object instance (or null for static methods)
685         * @param parameters the parameters to the method
686         * @return the result of the method invocation
687         */
688        public static Object invokeMethod(Method method, Object instance, Object... parameters) {
689            try {
690                return method.invoke(instance, parameters);
691            } catch (IllegalAccessException e) {
692                throw new RuntimeCamelException(e);
693            } catch (InvocationTargetException e) {
694                throw new RuntimeCamelException(e.getCause());
695            }
696        }
697    
698        /**
699         * Tests whether the target method overrides the source method.
700         * <p/>
701         * Tests whether they have the same name, return type, and parameter list.
702         *
703         * @param source  the source method
704         * @param target  the target method
705         * @return <tt>true</tt> if it override, <tt>false</tt> otherwise
706         */
707        public static boolean isOverridingMethod(Method source, Method target) {
708            if (source.getName().equals(target.getName())
709                    && source.getReturnType().equals(target.getReturnType()) 
710                    && source.getParameterTypes().length == target.getParameterTypes().length) {
711    
712                // test if parameter types is the same as well
713                for (int i = 0; i < source.getParameterTypes().length; i++) {
714                    if (!(source.getParameterTypes()[i].equals(target.getParameterTypes()[i]))) {
715                        return false;
716                    }
717                }
718    
719                // the have same name, return type and parameter list, so its overriding
720                return true;
721            }
722    
723            return false;
724        }
725    
726        /**
727         * Returns a list of methods which are annotated with the given annotation
728         *
729         * @param type the type to reflect on
730         * @param annotationType the annotation type
731         * @return a list of the methods found
732         */
733        public static List<Method> findMethodsWithAnnotation(Class<?> type,
734                                                             Class<? extends Annotation> annotationType) {
735            return findMethodsWithAnnotation(type, annotationType, false);
736        }
737    
738        /**
739         * Returns a list of methods which are annotated with the given annotation
740         *
741         * @param type the type to reflect on
742         * @param annotationType the annotation type
743         * @param checkMetaAnnotations check for meta annotations
744         * @return a list of the methods found
745         */
746        public static List<Method> findMethodsWithAnnotation(Class<?> type,
747                                                             Class<? extends Annotation> annotationType,
748                                                             boolean checkMetaAnnotations) {
749            List<Method> answer = new ArrayList<Method>();
750            do {
751                Method[] methods = type.getDeclaredMethods();
752                for (Method method : methods) {
753                    if (hasAnnotation(method, annotationType, checkMetaAnnotations)) {
754                        answer.add(method);
755                    }
756                }
757                type = type.getSuperclass();
758            } while (type != null);
759            return answer;
760        }
761    
762        /**
763         * Checks if a Class or Method are annotated with the given annotation
764         *
765         * @param elem the Class or Method to reflect on
766         * @param annotationType the annotation type
767         * @param checkMetaAnnotations check for meta annotations
768         * @return true if annotations is present
769         */
770        public static boolean hasAnnotation(AnnotatedElement elem, Class<? extends Annotation> annotationType,
771                                            boolean checkMetaAnnotations) {
772            if (elem.isAnnotationPresent(annotationType)) {
773                return true;
774            }
775            if (checkMetaAnnotations) {
776                for (Annotation a : elem.getAnnotations()) {
777                    for (Annotation meta : a.annotationType().getAnnotations()) {
778                        if (meta.annotationType().getName().equals(annotationType.getName())) {
779                            return true;
780                        }
781                    }
782                }
783            }
784            return false;
785        }
786    
787        /**
788         * Turns the given object arrays into a meaningful string
789         *
790         * @param objects an array of objects or null
791         * @return a meaningful string
792         */
793        public static String asString(Object[] objects) {
794            if (objects == null) {
795                return "null";
796            } else {
797                StringBuffer buffer = new StringBuffer("{");
798                int counter = 0;
799                for (Object object : objects) {
800                    if (counter++ > 0) {
801                        buffer.append(", ");
802                    }
803                    String text = (object == null) ? "null" : object.toString();
804                    buffer.append(text);
805                }
806                buffer.append("}");
807                return buffer.toString();
808            }
809        }
810    
811        /**
812         * Returns true if a class is assignable from another class like the
813         * {@link Class#isAssignableFrom(Class)} method but which also includes
814         * coercion between primitive types to deal with Java 5 primitive type
815         * wrapping
816         */
817        public static boolean isAssignableFrom(Class a, Class b) {
818            a = convertPrimitiveTypeToWrapperType(a);
819            b = convertPrimitiveTypeToWrapperType(b);
820            return a.isAssignableFrom(b);
821        }
822    
823        /**
824         * Converts primitive types such as int to its wrapper type like
825         * {@link Integer}
826         */
827        public static Class convertPrimitiveTypeToWrapperType(Class type) {
828            Class rc = type;
829            if (type.isPrimitive()) {
830                if (type == int.class) {
831                    rc = Integer.class;
832                } else if (type == long.class) {
833                    rc = Long.class;
834                } else if (type == double.class) {
835                    rc = Double.class;
836                } else if (type == float.class) {
837                    rc = Float.class;
838                } else if (type == short.class) {
839                    rc = Short.class;
840                } else if (type == byte.class) {
841                    rc = Byte.class;
842                    // TODO: Why is boolean disabled
843                    /*
844                     * } else if (type == boolean.class) { rc = Boolean.class;
845                     */
846                }
847            }
848            return rc;
849        }
850    
851        /**
852         * Helper method to return the default character set name
853         */
854        public static String getDefaultCharacterSet() {
855            return Charset.defaultCharset().name();
856        }
857    
858        /**
859         * Returns the Java Bean property name of the given method, if it is a
860         * setter
861         */
862        public static String getPropertyName(Method method) {
863            String propertyName = method.getName();
864            if (propertyName.startsWith("set") && method.getParameterTypes().length == 1) {
865                propertyName = propertyName.substring(3, 4).toLowerCase() + propertyName.substring(4);
866            }
867            return propertyName;
868        }
869    
870        /**
871         * Returns true if the given collection of annotations matches the given
872         * type
873         */
874        public static boolean hasAnnotation(Annotation[] annotations, Class<?> type) {
875            for (Annotation annotation : annotations) {
876                if (type.isInstance(annotation)) {
877                    return true;
878                }
879            }
880            return false;
881        }
882    
883        /**
884         * Closes the given resource if it is available, logging any closing
885         * exceptions to the given log
886         *
887         * @param closeable the object to close
888         * @param name the name of the resource
889         * @param log the log to use when reporting closure warnings
890         */
891        public static void close(Closeable closeable, String name, Log log) {
892            if (closeable != null) {
893                try {
894                    closeable.close();
895                } catch (IOException e) {
896                    if (log != null) {
897                        log.warn("Cannot close: " + name + ". Reason: " + e, e);
898                    }
899                }
900            }
901        }
902    
903        /**
904         * Converts the given value to the required type or throw a meaningful exception
905         */
906        @SuppressWarnings("unchecked")
907        public static <T> T cast(Class<T> toType, Object value) {
908            if (toType == boolean.class) {
909                return (T)cast(Boolean.class, value);
910            } else if (toType.isPrimitive()) {
911                Class newType = convertPrimitiveTypeToWrapperType(toType);
912                if (newType != toType) {
913                    return (T)cast(newType, value);
914                }
915            }
916            try {
917                return toType.cast(value);
918            } catch (ClassCastException e) {
919                throw new IllegalArgumentException("Failed to convert: " + value + " to type: "
920                                                   + toType.getName() + " due to: " + e, e);
921            }
922        }
923    
924        /**
925         * A helper method to create a new instance of a type using the default
926         * constructor arguments.
927         */
928        public static <T> T newInstance(Class<T> type) {
929            try {
930                return type.newInstance();
931            } catch (InstantiationException e) {
932                throw new RuntimeCamelException(e);
933            } catch (IllegalAccessException e) {
934                throw new RuntimeCamelException(e);
935            }
936        }
937    
938        /**
939         * A helper method to create a new instance of a type using the default
940         * constructor arguments.
941         */
942        public static <T> T newInstance(Class<?> actualType, Class<T> expectedType) {
943            try {
944                Object value = actualType.newInstance();
945                return cast(expectedType, value);
946            } catch (InstantiationException e) {
947                throw new RuntimeCamelException(e);
948            } catch (IllegalAccessException e) {
949                throw new RuntimeCamelException(e);
950            }
951        }
952    
953        /**
954         * Returns true if the given name is a valid java identifier
955         */
956        public static boolean isJavaIdentifier(String name) {
957            if (name == null) {
958                return false;
959            }
960            int size = name.length();
961            if (size < 1) {
962                return false;
963            }
964            if (Character.isJavaIdentifierStart(name.charAt(0))) {
965                for (int i = 1; i < size; i++) {
966                    if (!Character.isJavaIdentifierPart(name.charAt(i))) {
967                        return false;
968                    }
969                }
970                return true;
971            }
972            return false;
973        }
974    
975        /**
976         * Returns the type of the given object or null if the value is null
977         */
978        public static Object type(Object bean) {
979            return bean != null ? bean.getClass() : null;
980        }
981    
982        /**
983         * Evaluate the value as a predicate which attempts to convert the value to
984         * a boolean otherwise true is returned if the value is not null
985         */
986        public static boolean evaluateValuePredicate(Object value) {
987            if (value instanceof Boolean) {
988                return (Boolean)value;
989            } else if (value instanceof String) {
990                if ("true".equals(value)) {
991                    return true;
992                } else if ("false".equals(value)) {
993                    return false;
994                }
995            }
996            return value != null;
997        }
998    
999        /**
1000         * Wraps the caused exception in a {@link RuntimeCamelException} if its not
1001         * already such an exception.
1002         *
1003         * @param e the caused exception
1004         * @return the wrapper exception
1005         */
1006        public static RuntimeCamelException wrapRuntimeCamelException(Throwable e) {
1007            if (e instanceof RuntimeCamelException) {
1008                // don't double wrap
1009                return (RuntimeCamelException)e;
1010            } else {
1011                return new RuntimeCamelException(e);
1012            }
1013        }
1014    
1015        /**
1016         * Wraps the caused exception in a {@link CamelExecutionException} if its not
1017         * already such an exception.
1018         *
1019         * @param e the caused exception
1020         * @return the wrapper exception
1021         */
1022        public static CamelExecutionException wrapCamelExecutionException(Exchange exchange, Throwable e) {
1023            if (e instanceof CamelExecutionException) {
1024                // don't double wrap
1025                return (CamelExecutionException)e;
1026            } else {
1027                return new CamelExecutionException("Exception occured during execution", exchange, e);
1028            }
1029        }
1030    
1031        /**
1032         * Cleans the string to pure java identifier so we can use it for loading class names.
1033         * <p/>
1034         * Especially from Sping DSL people can have \n \t or other characters that otherwise
1035         * would result in ClassNotFoundException
1036         *
1037         * @param name the class name
1038         * @return normalized classname that can be load by a class loader.
1039         */
1040        public static String normalizeClassName(String name) {
1041            StringBuffer sb = new StringBuffer(name.length());
1042            for (char ch : name.toCharArray()) {
1043                if (ch == '.' || ch == '[' || ch == ']' || Character.isJavaIdentifierPart(ch)) {
1044                    sb.append(ch);
1045                }
1046            }
1047            return sb.toString();
1048        }
1049    
1050        /**
1051         * Creates an iterator to walk the exception from the bottom up
1052         * (the last caused by going upwards to the root exception).
1053         *
1054         * @param exception  the exception
1055         * @return the iterator
1056         */
1057        public static Iterator<Throwable> createExceptionIterator(Throwable exception) {
1058            return new ExceptionIterator(exception);
1059        }
1060    
1061        /**
1062         * Creates a {@link Scanner} for scanning the given value.
1063         *
1064         * @param exchange  the current exchange
1065         * @param value     the value, typically the message IN body
1066         * @return the scanner, is newer <tt>null</tt>
1067         */
1068        public static Scanner getScanner(Exchange exchange, Object value) {
1069            if (value instanceof GenericFile) {
1070                // generic file is just a wrapper for the real file so call again with the real file
1071                GenericFile gf = (GenericFile) value;
1072                return getScanner(exchange, gf.getFile());
1073            }
1074    
1075            String charset = exchange.getProperty(Exchange.CHARSET_NAME, String.class);
1076            Scanner scanner = null;
1077            if (value instanceof Readable) {
1078                scanner = new Scanner((Readable)value);
1079            } else if (value instanceof InputStream) {
1080                scanner = charset == null ? new Scanner((InputStream)value) : new Scanner((InputStream)value, charset);
1081            } else if (value instanceof File) {
1082                try {
1083                    scanner = charset == null ? new Scanner((File)value) : new Scanner((File)value, charset);
1084                } catch (FileNotFoundException e) {
1085                    throw new RuntimeCamelException(e);
1086                }
1087            } else if (value instanceof String) {
1088                scanner = new Scanner((String)value);
1089            } else if (value instanceof ReadableByteChannel) {
1090                scanner = charset == null ? new Scanner((ReadableByteChannel)value) : new Scanner((ReadableByteChannel)value, charset);
1091            }
1092    
1093            if (scanner == null) {
1094                // value is not a suitable type, try to convert value to a string
1095                String text = exchange.getContext().getTypeConverter().convertTo(String.class, exchange, value);
1096                if (text != null) {
1097                    scanner = new Scanner(text);
1098                }
1099            }
1100    
1101            if (scanner == null) {
1102                scanner = new Scanner("");
1103            }
1104    
1105            return scanner;
1106        }
1107    
1108        private static class ExceptionIterator implements Iterator<Throwable> {
1109            private List<Throwable> tree = new ArrayList<Throwable>();
1110            private Iterator<Throwable> it;
1111    
1112            public ExceptionIterator(Throwable exception) {
1113                Throwable current = exception;
1114                // spool to the bottom of the caused by tree
1115                while (current != null) {
1116                    tree.add(current);
1117                    current = current.getCause();
1118                }
1119    
1120                // reverse tree so we go from bottom to top
1121                Collections.reverse(tree);
1122                it = tree.iterator();
1123            }
1124    
1125            public boolean hasNext() {
1126                return it.hasNext();
1127            }
1128    
1129            public Throwable next() {
1130                return it.next();
1131            }
1132    
1133            public void remove() {
1134                it.remove();
1135            }
1136        }
1137    
1138    }