CompareUtil

java
package com.daojia.beauty.open.utils;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import java.lang.reflect.Method;
import java.util.Comparator;

/**
 * 数据比较<br />
 */
public class CompareUtil {

    private static final Logger LOGGER = LoggerFactory.getLogger(CompareUtil.class);

    /**
     *
     */
    private CompareUtil() {

    }
    /**
     * 数据比较
     * @param compare1
     * @param compare2
     * @param <T>
     * @return 0-->相等 , >0 小于 , <0 大于 , null --> 异常情况
     */
    public static <T> Integer compare(T compare1 , T compare2 ) {
        if(compare1.getClass() != compare2.getClass()) {
            throw new IllegalArgumentException("参与比较的两个对象必须属于一个类");
        }

        Method method = isComparable(compare1.getClass()) ;

        Integer results = null ;

        if(method == null) {
            throw new UnsupportedOperationException("当前类没有实现Comparable或Comparator接口");
        }
        try {
            results =  (Integer)method.invoke(compare1, compare2);
            return results;
        }catch (Exception e) {
            LOGGER.error("反射比较对象大小出现异常",e);
        }
        return results;
    }

    /**
     * 判断是否可比较
     * @return
     */
    private static Method isComparable(Class cls) {

        Class[] interfaces = cls.getInterfaces();
        Method method = null;
        try {
            for (Class cs : interfaces) {
                if (cs == Comparable.class) {
                    method = cls.getMethod("compareTo", cls);
                }
                if (cs == Comparator.class) {
                    method = cls.getMethod("compare",cls);
                }
            }
        } catch (Exception exception) {
            LOGGER.error("反射获取比较对象的compareTo和compare方法出错",exception);
        }
        return method;
    }
}