须要继承Map的equals函数和hashCode函数

package com.category;

import java.util.HashMap;

public class GenCategoryLevelData {

	private static HashMap<Category, Integer> categoryLevel = new HashMap<Category, Integer>();

	/**

	 * @param args

	 */

	public static void main(String[] args) {

		// TODO Auto-generated method stub

	}

	/**

	 * 分类

	 * @author ouyangyewei

	 *

	 */

	public static class Category {

		public long categoryId;

		public String categoryName;

		@Override

		public boolean equals(Object obj) {

			Category category = (Category)obj;

			return (this.categoryId==category.categoryId

					&& this.categoryName.equals(category.categoryName));

		}

		@Override

		public final int hashCode() {

            int hashCode = 17;

            hashCode = hashCode * 31 + 1;

            hashCode = hashCode * 31 + 1;

            return hashCode;

        }

		public Category() {

			// empty

		}

		public Category(long categoryId, String categoryName) {

			this.categoryId = categoryId;

			this.categoryName = categoryName;

		}

		public long getCategoryId() {

			return categoryId;

		}

		public void setCategoryId(long categoryId) {

			this.categoryId = categoryId;

		}

		public String getCategoryName() {

			return categoryName;

		}

		public void setCategoryName(String categoryName) {

			this.categoryName = categoryName;

		}

	}

}