Java如何比较两个对象并获取不相等的字段详解

<dependency>
    <groupId>com.github.dadiyang</groupId>
    <artifactId>equator</artifactId>
    <version>1.0.3</version>
</dependency>

Equator equator = new GetterBaseEquator();
User user1 = new User(...);
User user2 = new User(...);
// 判断属性是否完全相等
equator.isEquals(user1, user2);
// 获取不同的属性
List<FieldInfo> diff = equator.getDiffFields(user1, user2);

/**
 * 日期在数据库不保存毫秒数，因此需要特殊处理，比对时间时，忽略毫秒数
 *
 * @author dadiyang
 * @date 2019/3/23
 */
public class MmInsensitiveEquator extends GetterBaseEquator {
    @Override
    protected boolean isFieldEquals(FieldInfo fieldInfo) {
        if (fieldInfo.getFirstVal() instanceof Date) {
            Date first = (Date) fieldInfo.getFirstVal();
            Date second = (Date) fieldInfo.getSecondVal();
            if (Objects.equals(first, second)) {
                return true;
            }
            // 忽略毫秒数
            return Objects.equals(Math.round(first.getTime() / 1000), Math.round(second.getTime() / 1000));
        }
        return super.isFieldEquals(fieldInfo);
    }
}

package com.shiyan.utils.object;
 
import java.lang.reflect.Field;
import java.util.HashMap;
import java.util.Map;
 
import org.apache.commons.lang3.StringUtils;
 
public class GetDifference {
 
	public static Map<String, String> getUser(Object a, Object b)
			throws IllegalArgumentException, IllegalAccessException {
		Map<String, String> map = new HashMap<String, String>();
		Field[] declaredFields2 = a.getClass().getDeclaredFields();
		Field[] declaredFields23 = b.getClass().getDeclaredFields();
		StringBuilder xiugaiqian = new StringBuilder();
		StringBuffer xiugaihou = new StringBuffer();
		for (int i = 0; i < declaredFields2.length; i++) {
			declaredFields2[i].setAccessible(true);
			declaredFields23[i].setAccessible(true);
			if (declaredFields2[i].get(a) != null && declaredFields23[i].get(b) != null) {
 
				if (!declaredFields2[i].get(a).equals(declaredFields23[i].get(b))) {
					xiugaiqian.append(declaredFields2[i].getName() + ":" + declaredFields2[i].get(a)).append(",");
					xiugaihou.append(declaredFields23[i].getName() + ":" + declaredFields23[i].get(b)).append(",");
				}
			} else if (declaredFields2[i].get(a) == null && declaredFields23[i].get(b) != null) {
				xiugaiqian.append(declaredFields2[i].getName() + ":" + null).append(",");
				xiugaihou.append(declaredFields23[i].getName() + ":" + declaredFields23[i].get(b)).append(",");
			} else if (declaredFields2[i].get(a) != null && declaredFields23[i].get(b) == null) {
				xiugaiqian.append(declaredFields2[i].getName() + ":" + declaredFields2[i].get(a)).append(",");
				xiugaihou.append(declaredFields23[i].getName() + ":" + null).append(",");
			}
		}
 
		if (StringUtils.isNoneBlank(xiugaiqian.toString()) && StringUtils.isNoneBlank(xiugaihou.toString())) {
			map.put(xiugaiqian.toString().substring(0, xiugaiqian.length() - 1),
					xiugaihou.toString().substring(0, xiugaihou.length() - 1));
		}
		return map;
 
	}
}

/**
 * 
 * Description：   
 * @Author：xieyuxin 
 * @param 
 * @param 设定文件   
 * @throws 
 * @return String    
 * @Exception 异常对象
 */
package com.shiyan.test;
 
import java.util.Map;
import com.shiyan.utils.object.GetDifference;
 
 
public class ObjectGetEerro {
 
	public static void main(String[] args) throws IllegalArgumentException, IllegalAccessException {
		Persion p1 = new Persion.Builder().age(12).name("张三").t("2018-10-20").build();
		Persion p2 = new Persion.Builder().age(16).name("1111").build();
		Map<String, String> user = GetDifference.getUser(p1, p2);
		for(Map.Entry<String, String> entry : user.entrySet()){
			 System.out.println("修改前 :" + entry.getKey());
			 System.out.println("修改后 :" + entry.getValue());
		}
	}
 
}