org.springframework.core.enums.AbstractCachingLabeledEnumResolver Maven / Gradle / Ivy
/*
* Copyright 2002-2005 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 org.springframework.core.enums;
import java.util.Collections;
import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;
import java.util.Set;
import java.util.TreeSet;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.springframework.util.Assert;
import org.springframework.util.CachingMapDecorator;
/**
* Abstract base class for LabeledEnumResolver implementations,
* caching all retrieved LabeledEnum instances.
*
* Subclasses need to implement the template method
* findLabeledEnums(type).
*
* @author Keith Donald
* @author Juergen Hoeller
* @since 1.2.2
* @see #findLabeledEnums(Class)
*/
public abstract class AbstractCachingLabeledEnumResolver implements LabeledEnumResolver {
protected transient final Log logger = LogFactory.getLog(getClass());
private CachingMapDecorator labeledEnumCache = new CachingMapDecorator() {
protected Object create(Object key) {
Set typeEnums = findLabeledEnums((Class) key);
if (typeEnums == null || typeEnums.isEmpty()) {
throw new IllegalArgumentException(
"Unsupported labeled enumeration type '" + key + "': "
+ "make sure you've properly defined this enumeration: "
+ "if it's static, are the class and its fields public/static/final?");
}
Map typeEnumMap = new HashMap(typeEnums.size());
for (Iterator it = typeEnums.iterator(); it.hasNext();) {
LabeledEnum labeledEnum = (LabeledEnum) it.next();
typeEnumMap.put(labeledEnum.getCode(), labeledEnum);
}
return Collections.unmodifiableMap(typeEnumMap);
}
};
public Set getLabeledEnumSet(Class type) throws IllegalArgumentException {
return new TreeSet(getLabeledEnumMap(type).values());
}
public Map getLabeledEnumMap(Class type) throws IllegalArgumentException {
Assert.notNull(type, "No type specified");
return (Map) this.labeledEnumCache.get(type);
}
public LabeledEnum getLabeledEnumByCode(Class type, Comparable code) throws IllegalArgumentException {
Assert.notNull(code, "No enum code specified");
Map typeEnums = getLabeledEnumMap(type);
LabeledEnum codedEnum = (LabeledEnum) typeEnums.get(code);
if (codedEnum == null) {
throw new IllegalArgumentException(
"No enumeration with code '" + code + "'" + " of type [" + type.getName()
+ "] exists: this is likely a configuration error; "
+ "make sure the code value matches a valid instance's code property");
}
return codedEnum;
}
public LabeledEnum getLabeledEnumByLabel(Class type, String label) throws IllegalArgumentException {
Map typeEnums = getLabeledEnumMap(type);
Iterator it = typeEnums.values().iterator();
while (it.hasNext()) {
LabeledEnum value = (LabeledEnum) it.next();
if (value.getLabel().equalsIgnoreCase(label)) {
return value;
}
}
throw new IllegalArgumentException(
"No enumeration with label '" + label + "' of type [" + type
+ "] exists: this is likely a configuration error; "
+ "make sure the label string matches a valid instance's label property");
}
/**
* Template method to be implemented by subclasses.
* Supposed to find all LabeledEnum instances for the given type.
* @param type the enum type
* @return the Set of LabeledEnum instances
* @see org.springframework.core.enums.LabeledEnum
*/
protected abstract Set findLabeledEnums(Class type);
}