PropertyFilter.java

package com.norteksoft.product.orm;

import java.util.Date;

import org.apache.commons.lang.StringUtils;
import org.springframework.util.Assert;

/**
 * 与具体ORM实现无关的属性过滤条件封装类.
 * 
 * PropertyFilter主要记录页面中简单的搜索过滤条件,比Hibernate的Criterion要简单.
 * 
 * TODO:扩展其他对比方式如大于、小于及其他数据类型如数字和日期.
 * 
 */
public class PropertyFilter {

	/**
	 * 多个属性间OR关系的分隔符.
	 */
	private static final String OR_SEPARATOR = "_OR_";

	/**
	 * 属性比较类型.
	 */
	public enum MatchType {
		EQ, LIKE, LT, GT, LE, GE;
	}

	/**
	 * 属性数据类型.
	 */
	public enum PropertyType {
		S(String.class), I(Integer.class), L(Long.class), F(Float.class), D(Date.class);

		PropertyType(Class<?> clazz) {
			this.clazz = clazz;
		}

		private Class<?> clazz;

		public Class<?> getValue() {
			return clazz;
		}
	}

	private String[] propertyNames = null;
	private Class<?> propertyType = null;
	private Object propertyValue = null;
	private MatchType matchType = MatchType.EQ;

	public PropertyFilter() {
	}

	/**
	 * @param filterName 比较属性字符串,含待比较的比较类型、属性值类型及属性列表. 
	 *                   eg LIKES_NAME_OR_LOGIN_NAME
	 * @param value 待比较的值.
	 */
	public PropertyFilter(final String filterName, final Object value) {

		String matchTypeStr = StringUtils.substringBefore(filterName, "_");
		String matchTypeCode = StringUtils.substring(matchTypeStr, 0, matchTypeStr.length() - 1);
		String propertyTypeCode = StringUtils.substring(matchTypeStr, matchTypeStr.length() - 1, matchTypeStr.length());
		try {
			matchType = Enum.valueOf(MatchType.class, matchTypeCode);
		} catch (RuntimeException e) {
			throw new IllegalArgumentException("filter名称" + filterName + "没有按规则编写,无法得到属性比较类型.", e);
		}

		try {
			propertyType = Enum.valueOf(PropertyType.class, propertyTypeCode).getValue();
		} catch (RuntimeException e) {
			throw new IllegalArgumentException("filter名称" + filterName + "没有按规则编写,无法得到属性值类型.", e);
		}

		String propertyNameStr = StringUtils.substringAfter(filterName, "_");
		propertyNames = StringUtils.split(propertyNameStr, PropertyFilter.OR_SEPARATOR);

		Assert.isTrue(propertyNames.length > 0, "filter名称" + filterName + "没有按规则编写,无法得到属性名称.");

		this.propertyValue = value;
	}

	/**
	 * 是否有多个属性.
	 */
	public boolean isMultiProperty() {
		return (propertyNames.length > 1);
	}

	/**
	 * 获取比较属性名称列表.
	 */
	public String[] getPropertyNames() {
		return propertyNames;
	}

	/**
	 * 获取唯一的属性名称.
	 */
	public String getPropertyName() {
		if (propertyNames.length > 1)
			throw new IllegalArgumentException("There are not only one property");
		return propertyNames[0];
	}

	/**
	 * 获取比较值.
	 */
	public Object getPropertyValue() {
		return propertyValue;
	}

	/**
	 * 获取比较值的类型.
	 */
	public Class<?> getPropertyType() {
		return propertyType;
	}

	/**
	 * 获取比较类型.
	 */
	public MatchType getMatchType() {
		return matchType;
	}
}