org.springframework.beans.propertyeditors.CustomCollectionEditor Maven / Gradle / Ivy
/*
* Copyright 2002-2016 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
*
* https://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 org.springframework.beans.propertyeditors;
import java.beans.PropertyEditorSupport;
import java.lang.reflect.Array;
import java.util.ArrayList;
import java.util.Collection;
import java.util.LinkedHashSet;
import java.util.List;
import java.util.SortedSet;
import java.util.TreeSet;
/**
* Property editor for Collections, converting any source Collection
* to a given target Collection type.
*
* By default registered for Set, SortedSet and List,
* to automatically convert any given Collection to one of those
* target types if the type does not match the target property.
*
* @author Juergen Hoeller
* @since 1.1.3
* @see java.util.Collection
* @see java.util.Set
* @see java.util.SortedSet
* @see java.util.List
*/
public class CustomCollectionEditor extends PropertyEditorSupport {
@SuppressWarnings("rawtypes")
private final Class collectionType;
private final boolean nullAsEmptyCollection;
/**
* Create a new CustomCollectionEditor for the given target type,
* keeping an incoming {@code null} as-is.
* @param collectionType the target type, which needs to be a
* sub-interface of Collection or a concrete Collection class
* @see java.util.Collection
* @see java.util.ArrayList
* @see java.util.TreeSet
* @see java.util.LinkedHashSet
*/
@SuppressWarnings("rawtypes")
public CustomCollectionEditor(Class collectionType) {
this(collectionType, false);
}
/**
* Create a new CustomCollectionEditor for the given target type.
*
If the incoming value is of the given type, it will be used as-is.
* If it is a different Collection type or an array, it will be converted
* to a default implementation of the given Collection type.
* If the value is anything else, a target Collection with that single
* value will be created.
*
The default Collection implementations are: ArrayList for List,
* TreeSet for SortedSet, and LinkedHashSet for Set.
* @param collectionType the target type, which needs to be a
* sub-interface of Collection or a concrete Collection class
* @param nullAsEmptyCollection whether to convert an incoming {@code null}
* value to an empty Collection (of the appropriate type)
* @see java.util.Collection
* @see java.util.ArrayList
* @see java.util.TreeSet
* @see java.util.LinkedHashSet
*/
@SuppressWarnings("rawtypes")
public CustomCollectionEditor(Class collectionType, boolean nullAsEmptyCollection) {
if (collectionType == null) {
throw new IllegalArgumentException("Collection type is required");
}
if (!Collection.class.isAssignableFrom(collectionType)) {
throw new IllegalArgumentException(
"Collection type [" + collectionType.getName() + "] does not implement [java.util.Collection]");
}
this.collectionType = collectionType;
this.nullAsEmptyCollection = nullAsEmptyCollection;
}
/**
* Convert the given text value to a Collection with a single element.
*/
@Override
public void setAsText(String text) throws IllegalArgumentException {
setValue(text);
}
/**
* Convert the given value to a Collection of the target type.
*/
@Override
public void setValue(Object value) {
if (value == null && this.nullAsEmptyCollection) {
super.setValue(createCollection(this.collectionType, 0));
}
else if (value == null || (this.collectionType.isInstance(value) && !alwaysCreateNewCollection())) {
// Use the source value as-is, as it matches the target type.
super.setValue(value);
}
else if (value instanceof Collection) {
// Convert Collection elements.
Collection source = (Collection) value;
Collection