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/* * Copyright 2002-2012 the original author or authors. * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ package net.sf.juffrou.reflect; import java.beans.PropertyEditor; import java.lang.reflect.Array; import java.lang.reflect.Constructor; import java.lang.reflect.Field; import java.lang.reflect.Modifier; import java.util.Collection; import java.util.Iterator; import java.util.Map; import org.apache.commons.logging.Log; import org.apache.commons.logging.LogFactory; import org.springframework.beans.BeanUtils; import org.springframework.beans.BeanWrapperImpl; import org.springframework.beans.PropertyAccessor; import org.springframework.beans.PropertyEditorRegistrySupport; import org.springframework.beans.SimpleTypeConverter; import org.springframework.core.CollectionFactory; import org.springframework.core.MethodParameter; import org.springframework.core.convert.ConversionFailedException; import org.springframework.core.convert.ConversionService; import org.springframework.core.convert.TypeDescriptor; import org.springframework.util.ClassUtils; import org.springframework.util.StringUtils; /** * Internal helper class for converting property values to target types. * <p> * Works on a given {@link PropertyEditorRegistrySupport} instance. Used as a delegate by {@link BeanWrapperImpl} and * {@link SimpleTypeConverter}. * * @author Juergen Hoeller * @author Rob Harrop * @author Dave Syer * @since 2.0 * @see BeanWrapperImpl * @see SimpleTypeConverter */ class JuffrouTypeConverterDelegate { private static final Log logger = LogFactory.getLog(JuffrouTypeConverterDelegate.class); private final JuffrouSpringBeanWrapper propertyEditorRegistry; private final Object targetObject; /** * Create a new TypeConverterDelegate for the given editor registry. * * @param propertyEditorRegistry * the editor registry to use */ public JuffrouTypeConverterDelegate(JuffrouSpringBeanWrapper propertyEditorRegistry) { this(propertyEditorRegistry, null); } /** * Create a new TypeConverterDelegate for the given editor registry and bean instance. * * @param propertyEditorRegistry * the editor registry to use * @param targetObject * the target object to work on (as context that can be passed to editors) */ public JuffrouTypeConverterDelegate(JuffrouSpringBeanWrapper propertyEditorRegistry, Object targetObject) { this.propertyEditorRegistry = propertyEditorRegistry; this.targetObject = targetObject; } /** * Convert the value to the specified required type. * * @param newValue * the proposed new value * @param requiredType * the type we must convert to (or <code>null</code> if not known, for example in case of a collection * element) * @param methodParam * the method parameter that is the target of the conversion (may be <code>null</code>) * @return the new value, possibly the result of type conversion * @throws IllegalArgumentException * if type conversion failed */ public <T> T convertIfNecessary(Object newValue, Class<T> requiredType, MethodParameter methodParam) throws IllegalArgumentException { return convertIfNecessary(null, null, newValue, requiredType, (methodParam != null ? new TypeDescriptor(methodParam) : TypeDescriptor.valueOf(requiredType))); } /** * Convert the value to the required type for the specified property. * * @param propertyName * name of the property * @param oldValue * the previous value, if available (may be <code>null</code>) * @param newValue * the proposed new value * @param requiredType * the type we must convert to (or <code>null</code> if not known, for example in case of a collection * element) * @return the new value, possibly the result of type conversion * @throws IllegalArgumentException * if type conversion failed */ public <T> T convertIfNecessary(String propertyName, Object oldValue, Object newValue, Class<T> requiredType) throws IllegalArgumentException { return convertIfNecessary(propertyName, oldValue, newValue, requiredType, TypeDescriptor.valueOf(requiredType)); } /** * Convert the value to the required type (if necessary from a String), for the specified property. * * @param propertyName * name of the property * @param oldValue * the previous value, if available (may be <code>null</code>) * @param newValue * the proposed new value * @param requiredType * the type we must convert to (or <code>null</code> if not known, for example in case of a collection * element) * @param typeDescriptor * the descriptor for the target property or field * @return the new value, possibly the result of type conversion * @throws IllegalArgumentException * if type conversion failed */ @SuppressWarnings("unchecked") public <T> T convertIfNecessary(String propertyName, Object oldValue, Object newValue, Class<T> requiredType, TypeDescriptor typeDescriptor) throws IllegalArgumentException { Object convertedValue = newValue; // Custom editor for this type? PropertyEditor editor = this.propertyEditorRegistry.findCustomEditor(requiredType, propertyName); ConversionFailedException firstAttemptEx = null; // No custom editor but custom ConversionService specified? ConversionService conversionService = this.propertyEditorRegistry.getConversionService(); if (editor == null && conversionService != null && convertedValue != null && typeDescriptor != null) { TypeDescriptor sourceTypeDesc = TypeDescriptor.forObject(newValue); TypeDescriptor targetTypeDesc = typeDescriptor; if (conversionService.canConvert(sourceTypeDesc, targetTypeDesc)) { try { return (T) conversionService.convert(convertedValue, sourceTypeDesc, targetTypeDesc); } catch (ConversionFailedException ex) { // fallback to default conversion logic below firstAttemptEx = ex; } } } // Value not of required type? if (editor != null || (requiredType != null && !ClassUtils.isAssignableValue(requiredType, convertedValue))) { if (requiredType != null && Collection.class.isAssignableFrom(requiredType) && convertedValue instanceof String) { TypeDescriptor elementType = typeDescriptor.getElementTypeDescriptor(); if (elementType != null && Enum.class.isAssignableFrom(elementType.getType())) { convertedValue = StringUtils.commaDelimitedListToStringArray((String) convertedValue); } } if (editor == null) { editor = findDefaultEditor(requiredType); } convertedValue = doConvertValue(oldValue, convertedValue, requiredType, editor); } boolean standardConversion = false; if (requiredType != null) { // Try to apply some standard type conversion rules if appropriate. if (convertedValue != null) { if (requiredType.isArray()) { // Array required -> apply appropriate conversion of elements. if (convertedValue instanceof String && Enum.class.isAssignableFrom(requiredType.getComponentType())) { convertedValue = StringUtils.commaDelimitedListToStringArray((String) convertedValue); } return (T) convertToTypedArray(convertedValue, propertyName, requiredType.getComponentType()); } else if (convertedValue instanceof Collection) { // Convert elements to target type, if determined. convertedValue = convertToTypedCollection((Collection) convertedValue, propertyName, requiredType, typeDescriptor); standardConversion = true; } else if (convertedValue instanceof Map) { // Convert keys and values to respective target type, if determined. convertedValue = convertToTypedMap((Map) convertedValue, propertyName, requiredType, typeDescriptor); standardConversion = true; } if (convertedValue.getClass().isArray() && Array.getLength(convertedValue) == 1) { convertedValue = Array.get(convertedValue, 0); standardConversion = true; } if (String.class.equals(requiredType) && ClassUtils.isPrimitiveOrWrapper(convertedValue.getClass())) { // We can stringify any primitive value... return (T) convertedValue.toString(); } else if (convertedValue instanceof String && !requiredType.isInstance(convertedValue)) { if (firstAttemptEx == null && !requiredType.isInterface() && !requiredType.isEnum()) { try { Constructor strCtor = requiredType.getConstructor(String.class); return (T) BeanUtils.instantiateClass(strCtor, convertedValue); } catch (NoSuchMethodException ex) { // proceed with field lookup if (logger.isTraceEnabled()) { logger.trace("No String constructor found on type [" + requiredType.getName() + "]", ex); } } catch (Exception ex) { if (logger.isDebugEnabled()) { logger.debug( "Construction via String failed for type [" + requiredType.getName() + "]", ex); } } } String trimmedValue = ((String) convertedValue).trim(); if (requiredType.isEnum() && "".equals(trimmedValue)) { // It's an empty enum identifier: reset the enum value to null. return null; } convertedValue = attemptToConvertStringToEnum(requiredType, trimmedValue, convertedValue); standardConversion = true; } } if (!ClassUtils.isAssignableValue(requiredType, convertedValue)) { if (firstAttemptEx != null) { throw firstAttemptEx; } // Definitely doesn't match: throw IllegalArgumentException/IllegalStateException StringBuilder msg = new StringBuilder(); msg.append("Cannot convert value of type [").append(ClassUtils.getDescriptiveType(newValue)); msg.append("] to required type [").append(ClassUtils.getQualifiedName(requiredType)).append("]"); if (propertyName != null) { msg.append(" for property '").append(propertyName).append("'"); } if (editor != null) { msg.append(": PropertyEditor [").append(editor.getClass().getName()) .append("] returned inappropriate value of type [") .append(ClassUtils.getDescriptiveType(convertedValue)).append("]"); throw new IllegalArgumentException(msg.toString()); } else { msg.append(": no matching editors or conversion strategy found"); throw new IllegalStateException(msg.toString()); } } } if (firstAttemptEx != null) { if (editor == null && !standardConversion && requiredType != null && !Object.class.equals(requiredType)) { throw firstAttemptEx; } logger.debug("Original ConversionService attempt failed - ignored since " + "PropertyEditor based conversion eventually succeeded", firstAttemptEx); } return (T) convertedValue; } private Object attemptToConvertStringToEnum(Class<?> requiredType, String trimmedValue, Object currentConvertedValue) { Object convertedValue = currentConvertedValue; if (Enum.class.equals(requiredType)) { // target type is declared as raw enum, treat the trimmed value as <enum.fqn>.FIELD_NAME int index = trimmedValue.lastIndexOf("."); if (index > -1) { String enumType = trimmedValue.substring(0, index); String fieldName = trimmedValue.substring(index + 1); ClassLoader loader = this.targetObject.getClass().getClassLoader(); try { Class<?> enumValueType = loader.loadClass(enumType); Field enumField = enumValueType.getField(fieldName); convertedValue = enumField.get(null); } catch (ClassNotFoundException ex) { if (logger.isTraceEnabled()) { logger.trace("Enum class [" + enumType + "] cannot be loaded from [" + loader + "]", ex); } } catch (Throwable ex) { if (logger.isTraceEnabled()) { logger.trace("Field [" + fieldName + "] isn't an enum value for type [" + enumType + "]", ex); } } } } if (convertedValue == currentConvertedValue) { // Try field lookup as fallback: for JDK 1.5 enum or custom enum // with values defined as static fields. Resulting value still needs // to be checked, hence we don't return it right away. try { Field enumField = requiredType.getField(trimmedValue); convertedValue = enumField.get(null); } catch (Throwable ex) { if (logger.isTraceEnabled()) { logger.trace("Field [" + convertedValue + "] isn't an enum value", ex); } } } return convertedValue; } /** * Find a default editor for the given type. * * @param requiredType * the type to find an editor for * @return the corresponding editor, or <code>null</code> if none */ private PropertyEditor findDefaultEditor(Class requiredType) { PropertyEditor editor = null; if (requiredType != null) { // No custom editor -> check BeanWrapperImpl's default editors. editor = this.propertyEditorRegistry.getDefaultEditor(requiredType); if (editor == null && !String.class.equals(requiredType)) { // No BeanWrapper default editor -> check standard JavaBean editor. editor = BeanUtils.findEditorByConvention(requiredType); } } return editor; } /** * Convert the value to the required type (if necessary from a String), using the given property editor. * * @param oldValue * the previous value, if available (may be <code>null</code>) * @param newValue * the proposed new value * @param requiredType * the type we must convert to (or <code>null</code> if not known, for example in case of a collection * element) * @param editor * the PropertyEditor to use * @return the new value, possibly the result of type conversion * @throws IllegalArgumentException * if type conversion failed */ private Object doConvertValue(Object oldValue, Object newValue, Class<?> requiredType, PropertyEditor editor) { Object convertedValue = newValue; boolean sharedEditor = false; if (editor != null) { sharedEditor = this.propertyEditorRegistry.isSharedEditor(editor); } if (editor != null && !(convertedValue instanceof String)) { // Not a String -> use PropertyEditor's setValue. // With standard PropertyEditors, this will return the very same object; // we just want to allow special PropertyEditors to override setValue // for type conversion from non-String values to the required type. try { Object newConvertedValue; if (sharedEditor) { // Synchronized access to shared editor instance. synchronized (editor) { editor.setValue(convertedValue); newConvertedValue = editor.getValue(); } } else { // Unsynchronized access to non-shared editor instance. editor.setValue(convertedValue); newConvertedValue = editor.getValue(); } if (newConvertedValue != convertedValue) { convertedValue = newConvertedValue; // Reset PropertyEditor: It already did a proper conversion. // Don't use it again for a setAsText call. editor = null; } } catch (Exception ex) { if (logger.isDebugEnabled()) { logger.debug( "PropertyEditor [" + editor.getClass().getName() + "] does not support setValue call", ex); } // Swallow and proceed. } } Object returnValue = convertedValue; if (requiredType != null && !requiredType.isArray() && convertedValue instanceof String[]) { // Convert String array to a comma-separated String. // Only applies if no PropertyEditor converted the String array before. // The CSV String will be passed into a PropertyEditor's setAsText method, if any. if (logger.isTraceEnabled()) { logger.trace("Converting String array to comma-delimited String [" + convertedValue + "]"); } convertedValue = StringUtils.arrayToCommaDelimitedString((String[]) convertedValue); } if (convertedValue instanceof String) { if (editor != null) { // Use PropertyEditor's setAsText in case of a String value. if (logger.isTraceEnabled()) { logger.trace( "Converting String to [" + requiredType + "] using property editor [" + editor + "]"); } String newTextValue = (String) convertedValue; if (sharedEditor) { // Synchronized access to shared editor instance. synchronized (editor) { return doConvertTextValue(oldValue, newTextValue, editor); } } else { // Unsynchronized access to non-shared editor instance. return doConvertTextValue(oldValue, newTextValue, editor); } } else if (String.class.equals(requiredType)) { returnValue = convertedValue; } } return returnValue; } /** * Convert the given text value using the given property editor. * * @param oldValue * the previous value, if available (may be <code>null</code>) * @param newTextValue * the proposed text value * @param editor * the PropertyEditor to use * @return the converted value */ private Object doConvertTextValue(Object oldValue, String newTextValue, PropertyEditor editor) { try { editor.setValue(oldValue); } catch (Exception ex) { if (logger.isDebugEnabled()) { logger.debug("PropertyEditor [" + editor.getClass().getName() + "] does not support setValue call", ex); } // Swallow and proceed. } editor.setAsText(newTextValue); return editor.getValue(); } private Object convertToTypedArray(Object input, String propertyName, Class<?> componentType) { if (input instanceof Collection) { // Convert Collection elements to array elements. Collection coll = (Collection) input; Object result = Array.newInstance(componentType, coll.size()); int i = 0; for (Iterator it = coll.iterator(); it.hasNext(); i++) { Object value = convertIfNecessary(buildIndexedPropertyName(propertyName, i), null, it.next(), componentType); Array.set(result, i, value); } return result; } else if (input.getClass().isArray()) { // Convert array elements, if necessary. if (componentType.equals(input.getClass().getComponentType()) && !this.propertyEditorRegistry.hasCustomEditorForElement(componentType, propertyName)) { return input; } int arrayLength = Array.getLength(input); Object result = Array.newInstance(componentType, arrayLength); for (int i = 0; i < arrayLength; i++) { Object value = convertIfNecessary(buildIndexedPropertyName(propertyName, i), null, Array.get(input, i), componentType); Array.set(result, i, value); } return result; } else { // A plain value: convert it to an array with a single component. Object result = Array.newInstance(componentType, 1); Object value = convertIfNecessary(buildIndexedPropertyName(propertyName, 0), null, input, componentType); Array.set(result, 0, value); return result; } } @SuppressWarnings("unchecked") private Collection convertToTypedCollection(Collection original, String propertyName, Class requiredType, TypeDescriptor typeDescriptor) { if (!Collection.class.isAssignableFrom(requiredType)) { return original; } boolean approximable = CollectionFactory.isApproximableCollectionType(requiredType); if (!approximable && !canCreateCopy(requiredType)) { if (logger.isDebugEnabled()) { logger.debug("Custom Collection type [" + original.getClass().getName() + "] does not allow for creating a copy - injecting original Collection as-is"); } return original; } boolean originalAllowed = requiredType.isInstance(original); typeDescriptor = typeDescriptor.narrow(original); TypeDescriptor elementType = typeDescriptor.getElementTypeDescriptor(); if (elementType == null && originalAllowed && !this.propertyEditorRegistry.hasCustomEditorForElement(null, propertyName)) { return original; } Iterator it; try { it = original.iterator(); if (it == null) { if (logger.isDebugEnabled()) { logger.debug("Collection of type [" + original.getClass().getName() + "] returned null Iterator - injecting original Collection as-is"); } return original; } } catch (Throwable ex) { if (logger.isDebugEnabled()) { logger.debug("Cannot access Collection of type [" + original.getClass().getName() + "] - injecting original Collection as-is: " + ex); } return original; } Collection convertedCopy; try { if (approximable) { convertedCopy = CollectionFactory.createApproximateCollection(original, original.size()); } else { convertedCopy = (Collection) requiredType.newInstance(); } } catch (Throwable ex) { if (logger.isDebugEnabled()) { logger.debug("Cannot create copy of Collection type [" + original.getClass().getName() + "] - injecting original Collection as-is: " + ex); } return original; } int i = 0; for (; it.hasNext(); i++) { Object element = it.next(); String indexedPropertyName = buildIndexedPropertyName(propertyName, i); Object convertedElement = convertIfNecessary(indexedPropertyName, null, element, (elementType != null ? elementType.getType() : null), elementType); try { convertedCopy.add(convertedElement); } catch (Throwable ex) { if (logger.isDebugEnabled()) { logger.debug("Collection type [" + original.getClass().getName() + "] seems to be read-only - injecting original Collection as-is: " + ex); } return original; } originalAllowed = originalAllowed && (element == convertedElement); } return (originalAllowed ? original : convertedCopy); } @SuppressWarnings("unchecked") private Map convertToTypedMap(Map original, String propertyName, Class requiredType, TypeDescriptor typeDescriptor) { if (!Map.class.isAssignableFrom(requiredType)) { return original; } boolean approximable = CollectionFactory.isApproximableMapType(requiredType); if (!approximable && !canCreateCopy(requiredType)) { if (logger.isDebugEnabled()) { logger.debug("Custom Map type [" + original.getClass().getName() + "] does not allow for creating a copy - injecting original Map as-is"); } return original; } boolean originalAllowed = requiredType.isInstance(original); typeDescriptor = typeDescriptor.narrow(original); TypeDescriptor keyType = typeDescriptor.getMapKeyTypeDescriptor(); TypeDescriptor valueType = typeDescriptor.getMapValueTypeDescriptor(); if (keyType == null && valueType == null && originalAllowed && !this.propertyEditorRegistry.hasCustomEditorForElement(null, propertyName)) { return original; } Iterator it; try { it = original.entrySet().iterator(); if (it == null) { if (logger.isDebugEnabled()) { logger.debug("Map of type [" + original.getClass().getName() + "] returned null Iterator - injecting original Map as-is"); } return original; } } catch (Throwable ex) { if (logger.isDebugEnabled()) { logger.debug("Cannot access Map of type [" + original.getClass().getName() + "] - injecting original Map as-is: " + ex); } return original; } Map convertedCopy; try { if (approximable) { convertedCopy = CollectionFactory.createApproximateMap(original, original.size()); } else { convertedCopy = (Map) requiredType.newInstance(); } } catch (Throwable ex) { if (logger.isDebugEnabled()) { logger.debug("Cannot create copy of Map type [" + original.getClass().getName() + "] - injecting original Map as-is: " + ex); } return original; } while (it.hasNext()) { Map.Entry entry = (Map.Entry) it.next(); Object key = entry.getKey(); Object value = entry.getValue(); String keyedPropertyName = buildKeyedPropertyName(propertyName, key); Object convertedKey = convertIfNecessary(keyedPropertyName, null, key, (keyType != null ? keyType.getType() : null), keyType); Object convertedValue = convertIfNecessary(keyedPropertyName, null, value, (valueType != null ? valueType.getType() : null), valueType); try { convertedCopy.put(convertedKey, convertedValue); } catch (Throwable ex) { if (logger.isDebugEnabled()) { logger.debug("Map type [" + original.getClass().getName() + "] seems to be read-only - injecting original Map as-is: " + ex); } return original; } originalAllowed = originalAllowed && (key == convertedKey) && (value == convertedValue); } return (originalAllowed ? original : convertedCopy); } private String buildIndexedPropertyName(String propertyName, int index) { return (propertyName != null ? propertyName + PropertyAccessor.PROPERTY_KEY_PREFIX + index + PropertyAccessor.PROPERTY_KEY_SUFFIX : null); } private String buildKeyedPropertyName(String propertyName, Object key) { return (propertyName != null ? propertyName + PropertyAccessor.PROPERTY_KEY_PREFIX + key + PropertyAccessor.PROPERTY_KEY_SUFFIX : null); } private boolean canCreateCopy(Class requiredType) { return (!requiredType.isInterface() && !Modifier.isAbstract(requiredType.getModifiers()) && Modifier.isPublic(requiredType.getModifiers()) && ClassUtils.hasConstructor(requiredType)); } }