Java tutorial
/* This file is part of Cyclos (www.cyclos.org). A project of the Social Trade Organisation (www.socialtrade.org). Cyclos is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version. Cyclos is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with Cyclos; if not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */ package nl.strohalm.cyclos.utils.binding; import java.beans.IndexedPropertyDescriptor; import java.beans.PropertyDescriptor; import java.lang.reflect.InvocationTargetException; import java.util.Collection; import java.util.Map; import org.apache.commons.beanutils.BeanUtilsBean; import org.apache.commons.beanutils.DynaBean; import org.apache.commons.beanutils.DynaClass; import org.apache.commons.beanutils.DynaProperty; import org.apache.commons.beanutils.MappedPropertyDescriptor; import org.apache.commons.beanutils.PropertyUtils; import org.apache.commons.lang.StringUtils; /** * Customized bean utils in order to check if a mapped property refers to an array or single value * @author luis */ public class CustomBeanUtilsBean extends BeanUtilsBean { @Override public void setProperty(final Object bean, String name, final Object value) throws IllegalAccessException, InvocationTargetException { // Resolve any nested expression to get the actual target bean Object target = bean; final int delim = findLastNestedIndex(name); if (delim >= 0) { try { target = getPropertyUtils().getProperty(bean, name.substring(0, delim)); } catch (final NoSuchMethodException e) { return; // Skip this property setter } name = name.substring(delim + 1); } // Declare local variables we will require String propName = null; // Simple name of target property Class<?> type = null; // Java type of target property int index = -1; // Indexed subscript value (if any) String key = null; // Mapped key value (if any) // Calculate the property name, index, and key values propName = name; final int i = propName.indexOf(PropertyUtils.INDEXED_DELIM); if (i >= 0) { final int k = propName.indexOf(PropertyUtils.INDEXED_DELIM2); try { index = Integer.parseInt(propName.substring(i + 1, k)); } catch (final NumberFormatException e) { // Ignore } propName = propName.substring(0, i); } final int j = propName.indexOf(PropertyUtils.MAPPED_DELIM); if (j >= 0) { final int k = propName.indexOf(PropertyUtils.MAPPED_DELIM2); try { key = propName.substring(j + 1, k); } catch (final IndexOutOfBoundsException e) { // Ignore } propName = propName.substring(0, j); } // Calculate the property type if (target instanceof DynaBean) { final DynaClass dynaClass = ((DynaBean) target).getDynaClass(); final DynaProperty dynaProperty = dynaClass.getDynaProperty(propName); if (dynaProperty == null) { return; // Skip this property setter } type = dynaProperty.getType(); if (type.isArray() || Collection.class.isAssignableFrom(type)) { type = Object[].class; } } else { PropertyDescriptor descriptor = null; try { descriptor = getPropertyUtils().getPropertyDescriptor(target, name); if (descriptor == null) { return; // Skip this property setter } } catch (final NoSuchMethodException e) { return; // Skip this property setter } if (descriptor instanceof MappedPropertyDescriptor) { if (((MappedPropertyDescriptor) descriptor).getMappedWriteMethod() == null) { return; // Read-only, skip this property setter } type = ((MappedPropertyDescriptor) descriptor).getMappedPropertyType(); /** * Overriden behaviour ------------------- When a type is Object on a mapped property, retrieve the value to check if it's an array */ if (Object.class.equals(type)) { try { final Object retrieved = getPropertyUtils().getMappedProperty(target, propName, key); if (retrieved != null) { final Class<?> retrievedType = retrieved.getClass(); if (retrievedType.isArray() || Collection.class.isAssignableFrom(retrievedType)) { type = Object[].class; } } } catch (final NoSuchMethodException e) { throw new PropertyException(target, propName + "(" + key + ")"); } } } else if (descriptor instanceof IndexedPropertyDescriptor) { if (((IndexedPropertyDescriptor) descriptor).getIndexedWriteMethod() == null) { return; // Read-only, skip this property setter } type = ((IndexedPropertyDescriptor) descriptor).getIndexedPropertyType(); } else { if (descriptor.getWriteMethod() == null) { return; // Read-only, skip this property setter } type = descriptor.getPropertyType(); } } /** * Overriden behaviour ------------------- When a type is Map on a mapped property, retrieve the value to check if it's an array */ if (Map.class.isAssignableFrom(type) && StringUtils.isNotEmpty(key)) { try { final Map<?, ?> map = (Map<?, ?>) getPropertyUtils().getProperty(target, propName); final Object retrieved = map.get(key); if (retrieved != null) { final Class<?> retrievedType = retrieved.getClass(); if (retrievedType.isArray() || Collection.class.isAssignableFrom(retrievedType)) { type = Object[].class; } } } catch (final NoSuchMethodException e) { throw new PropertyException(target, propName + "(" + key + ")"); } } // Convert the specified value to the required type Object newValue = null; if (type.isArray() && (index < 0)) { // Scalar value into array if (value == null) { final String values[] = new String[1]; values[0] = (String) value; newValue = getConvertUtils().convert(values, type); } else if (value instanceof String) { final String values[] = new String[1]; values[0] = (String) value; newValue = getConvertUtils().convert(values, type); } else if (value instanceof String[]) { newValue = getConvertUtils().convert((String[]) value, type); } else { newValue = value; } } else if (type.isArray()) { // Indexed value into array if (value instanceof String) { newValue = getConvertUtils().convert((String) value, type.getComponentType()); } else if (value instanceof String[]) { newValue = getConvertUtils().convert(((String[]) value)[0], type.getComponentType()); } else { newValue = value; } } else { // Value into scalar if ((value instanceof String) || (value == null)) { newValue = getConvertUtils().convert((String) value, type); } else if (value instanceof String[]) { newValue = getConvertUtils().convert(((String[]) value)[0], type); } else if (getConvertUtils().lookup(value.getClass()) != null) { newValue = getConvertUtils().convert(value.toString(), type); } else { newValue = value; } } // Invoke the setter method try { if (index >= 0) { getPropertyUtils().setIndexedProperty(target, propName, index, newValue); } else if (key != null) { getPropertyUtils().setMappedProperty(target, propName, key, newValue); } else { getPropertyUtils().setProperty(target, propName, newValue); } } catch (final NoSuchMethodException e) { throw new InvocationTargetException(e, "Cannot set " + propName); } } private int findLastNestedIndex(final String expression) { // walk back from the end to the start // and find the first index that int bracketCount = 0; for (int i = expression.length() - 1; i >= 0; i--) { final char at = expression.charAt(i); switch (at) { case PropertyUtils.NESTED_DELIM: if (bracketCount < 1) { return i; } break; case PropertyUtils.MAPPED_DELIM: case PropertyUtils.INDEXED_DELIM: // not bothered which --bracketCount; break; case PropertyUtils.MAPPED_DELIM2: case PropertyUtils.INDEXED_DELIM2: // not bothered which ++bracketCount; break; } } // can't find any return -1; } }