rating.java

来自「Hibernate In Action 书的源代码」· Java 代码 · 共 43 行

package org.hibernate.auction.model;

import java.io.Serializable;
import java.util.*;

public class Rating implements Serializable {

	private String name;

	public static final Rating EXCELLENT = new Rating("Excellent");
	public static final Rating OK = new Rating("OK");
	public static final Rating LOW = new Rating("Low");

	private static final Map INSTANCES = new HashMap();

	static {
		INSTANCES.put(EXCELLENT.toString(), EXCELLENT);
		INSTANCES.put(OK.toString(), OK);
		INSTANCES.put(LOW.toString(), LOW);
	}

	/**
	 * Prevent instantiation and subclassing with a private constructor.
	 */
	private Rating(String name) {
		this.name = name;
	}

	// ********************** Common Methods ********************** //

	public String toString() {
		return name;
	}

	Object readResolve() {
		return getInstance(name);
	}

	public static Rating getInstance(String name) {
		return (Rating) INSTANCES.get(name);
	}

}