MutablePropertyValues.java

package org.theonefx.wcframework.ioc.val;

import java.io.Serializable;
import java.util.ArrayList;
import java.util.List;
import java.util.Map;

import org.theonefx.wcframework.ioc.PropertyValue;
import org.theonefx.wcframework.ioc.PropertyValues;
import org.theonefx.wcframework.utils.StringUtils;

/**
 * {@link PropertyValues}接口的默认实现.
 * 允许properties的简单操作，同时提供构造函数从map构建以及深度拷贝的支持
 */
public class MutablePropertyValues implements PropertyValues, Serializable {

	private static final long serialVersionUID = 1L;

	private final List<PropertyValue> propertyValueList;

	private volatile boolean converted = false;

	/**
	 * 创建一个新的MutablePropertyValues.
	 * <p>可以通过<code>addPropertyValues</code>方法添加PropertyValue.
	 * @see #addPropertyValues(String, Object)
	 * @see {@link PropertyValue}
	 */
	public MutablePropertyValues() {
		this.propertyValueList = new ArrayList<PropertyValue>(0);
	}

	/**
	 * 通过深度拷贝一个旧的MutablePropertyValues来创建一个新的MutablePropertyValues
	 * 保证 PropertyValue 的引用都是独立的，尽管他不能深度拷贝目前被个别PropertyValue对象引用的对象
	 * @param 原始PropertyValues，即以这个PropertyValues为模板创建一个新的MutablePropertyValues
	 * @see #addPropertyValues(PropertyValues)
	 */
	public MutablePropertyValues(PropertyValues original) {
		if (original != null) {
			PropertyValue[] pvs = original.getPropertyValues();
			this.propertyValueList = new ArrayList<PropertyValue>(pvs.length);
			for (PropertyValue pv : pvs) {
				this.propertyValueList.add(new PropertyValue(pv));
			}
		} else {
			this.propertyValueList = new ArrayList<PropertyValue>(0);
		}
	}

	/**
	 * 从一个Map构建一个新的MutablePropertyValues对象
	 * @param original 存有属性名和属性值的键值对Map
	 * @see #addPropertyValues(Map)
	 */
	public MutablePropertyValues(Map<?, ?> original) {
		if (original != null) {
			this.propertyValueList = new ArrayList<PropertyValue>(original.size());
			for (Map.Entry<?, ?> entry : original.entrySet()) {
				this.propertyValueList.add(new PropertyValue(entry.getKey().toString(), entry.getValue()));
			}
		} else {
			this.propertyValueList = new ArrayList<PropertyValue>(0);
		}
	}

	/**
	 * 从一个包含了PropertyValue的列表中构建新的MutablePropertyValues
	 * <p>该方法应用于一些高级应用场景.
	 * 它不适合典型的开发使用.
	 */
	public MutablePropertyValues(List<PropertyValue> propertyValueList) {
		this.propertyValueList = (propertyValueList != null ? propertyValueList : new ArrayList<PropertyValue>());
	}


	/**
	 * <p>这是访问所有PropertyValue的最优化的访问器.
	 * 它不适合典型的编程开发使用.
	 */
	public List<PropertyValue> getPropertyValueList() {
		return this.propertyValueList;
	}

	/**
	 * 返回PropertyValues中PropertyValue的数量（在list中）
	 */
	public int size() {
		return this.propertyValueList.size();
	}

	public MutablePropertyValues addPropertyValues(PropertyValues other) {
		if (other != null) {
			PropertyValue[] pvs = other.getPropertyValues();
			for (PropertyValue pv : pvs) {
				addPropertyValue(new PropertyValue(pv));
			}
		}
		return this;
	}

	public MutablePropertyValues addPropertyValues(Map<?, ?> other) {
		if (other != null) {
			for (Map.Entry<?, ?> entry : other.entrySet()) {
				addPropertyValue(new PropertyValue(entry.getKey().toString(), entry.getValue()));
			}
		}
		return this;
	}

	/**
	 * 添加一个新的PropertyValue对象, 如果存在同名的PropertyValue，则先尝试合并，不过不能合并（mergeIfRequired）则替换原有PropertyValu.
	 */
	@Override
	public MutablePropertyValues addPropertyValue(PropertyValue pv) {
		for (int i = 0; i < this.propertyValueList.size(); i++) {
			PropertyValue currentPv = this.propertyValueList.get(i);
			if (currentPv.getName().equals(pv.getName())) {
				pv = mergeIfRequired(pv, currentPv);
				setPropertyValueAt(pv, i);
				return this;
			}
		}
		this.propertyValueList.add(pv);
		return this;
	}

	@Override
	public void addPropertyValue(String propertyName, Object propertyValue) {
		addPropertyValue(new PropertyValue(propertyName, propertyValue));
	}

	public void setPropertyValueAt(PropertyValue pv, int i) {
		this.propertyValueList.set(i, pv);
	}

	private PropertyValue mergeIfRequired(PropertyValue newPv, PropertyValue currentPv) {
		Object value = newPv.getValue();
		if (value instanceof Mergeable) {
			Mergeable mergeable = (Mergeable) value;
			if (mergeable.isMergeEnabled()) {
				Object merged = mergeable.merge(currentPv.getValue());
				return new PropertyValue(newPv.getName(), merged);
			}
		}
		return newPv;
	}

	public void removePropertyValue(PropertyValue pv) {
		this.propertyValueList.remove(pv);
	}

	public void removePropertyValue(String propertyName) {
		removePropertyValue(getPropertyValue(propertyName));
	}


	@Override
	public PropertyValue[] getPropertyValues() {
		return this.propertyValueList.toArray(new PropertyValue[this.propertyValueList.size()]);
	}

	@Override
	public PropertyValue getPropertyValue(String propertyName) {
		for (PropertyValue pv : this.propertyValueList) {
			if (pv.getName().equals(propertyName)) {
				return pv;
			}
		}
		return null;
	}

	@Override
	public boolean contains(String propertyName) {
		return getPropertyValue(propertyName) != null;
	}

	@Override
	public boolean isEmpty() {
		return this.propertyValueList.isEmpty();
	}

	/**
	 * 将当前PropertyValues标记为只包含完成转换之后的值
	 * (也就是说，不再需要进行运行时的解析).
	 */
	public void setConverted() {
		this.converted = true;
	}

	/**
	 * 返回当前PropertyValues是否只包含转换之后的值(<code>true</code>),
	 * 或者包含的PropertyValue依然需要被转换(<code>false</code>).
	 */
	public boolean isConverted() {
		return this.converted;
	}


	@Override
	public boolean equals(Object other) {
		if (this == other) {
			return true;
		}
		if (!(other instanceof MutablePropertyValues)) {
			return false;
		}
		MutablePropertyValues that = (MutablePropertyValues) other;
		return this.propertyValueList.equals(that.propertyValueList);
	}

	@Override
	public int hashCode() {
		return this.propertyValueList.hashCode();
	}

	@Override
	public String toString() {
		PropertyValue[] pvs = getPropertyValues();
		StringBuilder sb = new StringBuilder("PropertyValues: length=").append(pvs.length);
		if (pvs.length > 0) {
			sb.append("; ").append(StringUtils.arrayToDelimitedString(pvs, "; "));
		}
		return sb.toString();
	}
}