org.joda.beans.impl.reflection.ReflectiveMetaBean Maven / Gradle / Ivy
/*
* Copyright 2001-present Stephen Colebourne
*
* 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.joda.beans.impl.reflection;
import java.lang.reflect.InvocationTargetException;
import java.util.Collections;
import java.util.LinkedHashMap;
import java.util.Map;
import org.joda.beans.Bean;
import org.joda.beans.BeanBuilder;
import org.joda.beans.MetaProperty;
import org.joda.beans.TypedMetaBean;
import org.joda.beans.impl.BasicBeanBuilder;
/**
* A meta-bean implementation that uses reflection.
*
* This is implementation of a meta-bean can be used directly by applications without code generation.
* It requires that the bean implements {@code Bean} and has a no-arguments constructor.
* Therefore, it is only suitable for mutable beans.
*
* Typically, the meta-bean will be created as a public static final constant.
* Only one method from {@link Bean} needs to be implemented, which simply returns the meta-bean.
*
* @param the type of the bean
*/
public final class ReflectiveMetaBean implements TypedMetaBean {
/** The bean type. */
private final Class beanType;
/** The meta-property instances of the bean. */
private final Map> metaPropertyMap;
/**
* Create a meta-bean and meta properties.
*
* The meta-properties will be created from the property names by searching for a getter and setter.
*
* @param the type of the bean
* @param beanClass the bean class, not null
* @param propertyNames the property names, not null
* @return the meta-bean, not null
*/
public static ReflectiveMetaBean of(Class beanClass, String... propertyNames) {
return new ReflectiveMetaBean<>(beanClass, propertyNames);
}
/**
* Constructor.
*
* @param beanType the bean type, not null
* @param propertyNames the property names, not null
*/
private ReflectiveMetaBean(Class beanType, String[] propertyNames) {
if (beanType == null) {
throw new NullPointerException("Bean class must not be null");
}
if (propertyNames == null) {
throw new NullPointerException("Property names must not be null");
}
this.beanType = beanType;
Map> map = new LinkedHashMap<>();
for (String name : propertyNames) {
map.put(name, new ReflectiveMetaProperty<>(this, beanType, name));
}
this.metaPropertyMap = Collections.unmodifiableMap(map);
}
//-----------------------------------------------------------------------
@Override
public boolean isBuildable() {
try {
beanType.getDeclaredConstructor().newInstance();
return true;
} catch (Exception ex) {
return false;
}
}
@Override
public BeanBuilder builder() {
try {
T bean = beanType.getDeclaredConstructor().newInstance();
return new BasicBeanBuilder<>(bean);
} catch (NoSuchMethodException | InvocationTargetException | InstantiationException | IllegalAccessException ex) {
throw new UnsupportedOperationException("Bean cannot be created: " + beanName(), ex);
}
}
@Override
public Class beanType() {
return beanType;
}
@Override
public Map> metaPropertyMap() {
return metaPropertyMap;
}
//-----------------------------------------------------------------------
@Override
public boolean equals(Object obj) {
if (obj instanceof ReflectiveMetaBean) {
ReflectiveMetaBean other = (ReflectiveMetaBean) obj;
return this.beanType.equals(other.beanType);
}
return false;
}
@Override
public int hashCode() {
return beanType.hashCode() + 3;
}
/**
* Returns a string that summarises the meta-bean.
*
* @return a summary string, not null
*/
@Override
public String toString() {
return "MetaBean:" + beanName();
}
}