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 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You 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
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 *     http://www.apache.org/licenses/LICENSE-2.0
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 * Unless required by applicable law or agreed to in writing, software
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package org.apache.commons.configuration2.beanutils;

import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collection;
import java.util.Collections;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

A special implementation of the BeanDeclaration interface which allows combining multiple BeanDeclaration objects.

An instance of this class can be used if a bean is defined using multiple sources. For instance, there can be one definition with default values and one with actual values; if actual values are provided, they are used; otherwise, the default values apply.

When constructing an instance an arbitrary number of child BeanDeclaration objects can be specified. The implementations of the BeanDeclaration methods implement a logical combination of the data returned by these child declarations. The order in which child declarations are added is relevant; first entries take precedence over later ones. The comments of the single methods explain in which way a combination of the child declarations is built.

Since:2.0
/** * <p> * A special implementation of the {@code BeanDeclaration} interface which * allows combining multiple {@code BeanDeclaration} objects. * </p> * <p> * An instance of this class can be used if a bean is defined using multiple * sources. For instance, there can be one definition with default values and * one with actual values; if actual values are provided, they are used; * otherwise, the default values apply. * </p> * <p> * When constructing an instance an arbitrary number of child * {@code BeanDeclaration} objects can be specified. The implementations of the * {@code BeanDeclaration} methods implement a logical combination of the data * returned by these child declarations. The order in which child declarations * are added is relevant; first entries take precedence over later ones. The * comments of the single methods explain in which way a combination of the * child declarations is built. * </p> * * @since 2.0 */
public class CombinedBeanDeclaration implements BeanDeclaration {
A list with the child declarations.
/** A list with the child declarations. */
private final List<BeanDeclaration> childDeclarations;
Creates a new instance of CombinedBeanDeclaration and initializes it with the given child declarations.
Params:
  • decl – the child declarations
Throws:
/** * Creates a new instance of {@code CombinedBeanDeclaration} and initializes * it with the given child declarations. * * @param decl the child declarations * @throws NullPointerException if the array with child declarations is * <b>null</b> */
public CombinedBeanDeclaration(final BeanDeclaration... decl) { childDeclarations = new ArrayList<>(Arrays.asList(decl)); }
{@inheritDoc} This implementation iterates over the list of child declarations and asks them for a bean factory name. The first non-null value is returned. If none of the child declarations have a defined bean factory name, result is null.
/** * {@inheritDoc} This implementation iterates over the list of child * declarations and asks them for a bean factory name. The first * non-<b>null</b> value is returned. If none of the child declarations have * a defined bean factory name, result is <b>null</b>. */
@Override public String getBeanFactoryName() { for (final BeanDeclaration d : childDeclarations) { final String factoryName = d.getBeanFactoryName(); if (factoryName != null) { return factoryName; } } return null; }
{@inheritDoc} This implementation iterates over the list of child declarations and asks them for a bean factory parameter. The first non-null value is returned. If none of the child declarations have a defined bean factory parameter, result is null.
/** * {@inheritDoc} This implementation iterates over the list of child * declarations and asks them for a bean factory parameter. The first * non-<b>null</b> value is returned. If none of the child declarations have * a defined bean factory parameter, result is <b>null</b>. */
@Override public Object getBeanFactoryParameter() { for (final BeanDeclaration d : childDeclarations) { final Object factoryParam = d.getBeanFactoryParameter(); if (factoryParam != null) { return factoryParam; } } return null; }
{@inheritDoc} This implementation iterates over the list of child declarations and asks them for the bean class name. The first non-null value is returned. If none of the child declarations have a defined bean class, result is null.
/** * {@inheritDoc} This implementation iterates over the list of child * declarations and asks them for the bean class name. The first * non-<b>null</b> value is returned. If none of the child declarations have * a defined bean class, result is <b>null</b>. */
@Override public String getBeanClassName() { for (final BeanDeclaration d : childDeclarations) { final String beanClassName = d.getBeanClassName(); if (beanClassName != null) { return beanClassName; } } return null; }
{@inheritDoc} This implementation creates a union of the properties returned by all child declarations. If a property is defined in multiple child declarations, the declaration that comes before in the list of children takes precedence.
/** * {@inheritDoc} This implementation creates a union of the properties * returned by all child declarations. If a property is defined in multiple * child declarations, the declaration that comes before in the list of * children takes precedence. */
@Override public Map<String, Object> getBeanProperties() { final Map<String, Object> result = new HashMap<>(); for (int i = childDeclarations.size() - 1; i >= 0; i--) { final Map<String, Object> props = childDeclarations.get(i).getBeanProperties(); if (props != null) { result.putAll(props); } } return result; }
{@inheritDoc} This implementation creates a union of the nested bean declarations returned by all child declarations. If a complex property is defined in multiple child declarations, the declaration that comes before in the list of children takes precedence.
/** * {@inheritDoc} This implementation creates a union of the nested bean * declarations returned by all child declarations. If a complex property is * defined in multiple child declarations, the declaration that comes before * in the list of children takes precedence. */
@Override public Map<String, Object> getNestedBeanDeclarations() { final Map<String, Object> result = new HashMap<>(); for (int i = childDeclarations.size() - 1; i >= 0; i--) { final Map<String, Object> decls = childDeclarations.get(i).getNestedBeanDeclarations(); if (decls != null) { result.putAll(decls); } } return result; }
{@inheritDoc} This implementation iterates over the list of child declarations and asks them for constructor arguments. The first non-null and non empty collection is returned. If none of the child declarations provide constructor arguments, result is an empty collection.
/** * {@inheritDoc} This implementation iterates over the list of child * declarations and asks them for constructor arguments. The first * non-<b>null</b> and non empty collection is returned. If none of the * child declarations provide constructor arguments, result is an empty * collection. */
@Override public Collection<ConstructorArg> getConstructorArgs() { for (final BeanDeclaration d : childDeclarations) { final Collection<ConstructorArg> args = d.getConstructorArgs(); if (args != null && !args.isEmpty()) { return args; } } return Collections.emptyList(); } }