复写equals方法

今天在开发中，有时需要判断两个对象是否一样，如果对象属性值是一样的，同样返回true，于是手动写了一个

BaseEntity:

package com.shinedata.entity.base;

import com.shinedata.util.bean.BeanUtils;

import java.io.Serializable;
import java.lang.reflect.Field;

/**
 * @ClassName BaseEntity
 * @Author yupanpan
 * @Date 2019/9/25 10:51
 */
public class BaseEntity implements Serializable {

    private static final long serialVersionUID = 8066035520257526507L;

    @Override
    public boolean equals(Object obj){
        if(obj==null){
            return false;
        }
        if(this==obj){
            return true;
        }
        if(this.getClass()!=obj.getClass()){
            return false;
        }
        Field[] declaredFields = this.getClass().getDeclaredFields();
        for (Field field : declaredFields) {
            String name = field.getName();
            Object objValue = BeanUtils.getFieldValueByFieldName(name, obj);
            Object thisValue = BeanUtils.getFieldValueByFieldName(name, this);
            if(field.getType().isPrimitive()){
                if(objValue!=thisValue){
                    return false;
                }
            }else {
                if(!objValue.equals(thisValue)){
                    return false;
                }
            }
        }
        return true;
    }
}

BeanUtils:

package com.shinedata.util.bean;

import org.apache.commons.lang3.StringUtils;
import org.springframework.util.CollectionUtils;

import java.beans.BeanInfo;
import java.beans.IntrospectionException;
import java.beans.Introspector;
import java.beans.PropertyDescriptor;
import java.lang.reflect.Field;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

/**
 * @ClassName BeanUtils
 * @Author yupanpan
 * @Date 2019/9/10 14:09
 */
public class BeanUtils {

    /**
     * 拷贝实体，source,target不允许为空
     * @param source
     * @param target
     */
    public static void copyProperties(Object source, Object target) {
        org.springframework.beans.BeanUtils.copyProperties(source, target);
    }

    /**
     * 拷贝实体集合，sourceList
     *只支持自定义实体集合拷贝
     *应用场景：DTO <=> DO 等
     */
    public static void copyPropertiesList(List sourceList, List targetList, Class clazz) throws Exception {
        if (CollectionUtils.isEmpty(sourceList)) {
            throw new NullPointerException();
        }
        for (Object items : sourceList) {
            Object target = clazz.newInstance();
            org.springframework.beans.BeanUtils.copyProperties(items, target);
            targetList.add(target);
        }

    }

    /**
     * Map --> Bean 2: 利用org.apache.commons.beanutils 工具类实现 Map --> Bean
     * @param map
     * @param obj
     */
    public static void transMap2Bean2(Map<String, Object> map, Object obj) throws InvocationTargetException, IllegalAccessException {
        if (map == null || obj == null) {
            return;
        }
        org.apache.commons.beanutils.BeanUtils.populate(obj, map);
    }

    /**
     * Map --> Bean 1: 利用Introspector,PropertyDescriptor实现 Map --> Bean
     * @param map
     * @param obj
     */
    public static void transMap2Bean(Map<String, Object> map, Object obj) throws InvocationTargetException, IllegalAccessException, IntrospectionException {
        BeanInfo beanInfo = Introspector.getBeanInfo(obj.getClass());
        PropertyDescriptor[] propertyDescriptors = beanInfo.getPropertyDescriptors();

        for (PropertyDescriptor property : propertyDescriptors) {
            String key = property.getName();
            if (map.containsKey(key)) {
                Object value = map.get(key);
                // 得到property对应的setter方法
                Method setter = property.getWriteMethod();
                setter.invoke(obj, value);
            }
        }
    }

    /**
     * Bean --> Map 1: 利用Introspector和PropertyDescriptor 将Bean --> Map
     * @param obj
     */
    public static Map<String, Object> transBean2Map(Object obj) throws IntrospectionException, InvocationTargetException, IllegalAccessException {

        if (obj == null) {
            return null;
        }
        Map<String, Object> map = new HashMap<String, Object>();
        BeanInfo beanInfo = Introspector.getBeanInfo(obj.getClass());
        PropertyDescriptor[] propertyDescriptors = beanInfo.getPropertyDescriptors();
        for (PropertyDescriptor property : propertyDescriptors) {
            String key = property.getName();

            // 过滤class属性
            if (!key.equals("class")) {
                // 得到property对应的getter方法
                Method getter = property.getReadMethod();
                Object value = getter.invoke(obj);

                map.put(key, value);
            }

        }
        return map;
    }

    /**
     * 反射根据属性名获取属性值
     * @param fieldName  属性名
     * @param object 实体类对象
     * @return
     */
    public static Object getFieldValueByFieldName(String fieldName, Object object) {
        try {
            Field field = object.getClass().getDeclaredField(fieldName);
            //设置对象的访问权限，保证对private的属性的访问
            field.setAccessible(true);
            return  field.get(object);
        } catch (Exception e) {
            e.printStackTrace();
            return null;
        }
    }

    /**
     * 通过反射设置属性的值
     * @param fieldName  属性名
     * @param fieldValue  属性值
     * @param object  实体类对象
     * @param parameterTypes  设置属性值的类型
     * @throws
     */
    public static void setFieldValueByFieldName(String fieldName,Object fieldValue,Object object,Class<?>... parameterTypes) {
        try {
            Field[] fields = object.getClass().getDeclaredFields();
            for(int i=0;i<fields.length;i++){
                Field field = fields[i];
                //字段名称
                String name = field.getName();
                if(name.equals(fieldName)){
                    //将属性的首字符大写，方便构造get，set方法
                    String methname = name.substring(0,1).toUpperCase()+name.substring(1);
                    Method m = object.getClass().getMethod("set" + methname,parameterTypes);
                    m.invoke(object,fieldValue);
                }
            }
        }catch (Exception e){
            e.printStackTrace();
        }
    }

    /**
     * 去除实体类所有String类型属性的空格
     * @author yupanpan
     * @date 2019/9/25 10:04
     * @param object
     * @param b true-去除字符串所有空格 false-只去除头尾空格
     * @return java.lang.Object
     */
    public static Object formatBeanStringBlankSpace(Object object,Boolean b){
        //获取该类中所有的域(属性)
        Field[] fields = object.getClass().getDeclaredFields();
        for(Field field : fields){
            //对所有的属性判断是否为String类型
            if(field.getType().equals(String.class)){
                //将私有属性设置为可访问状态
                field.setAccessible(true);
                try {
                    Object o = field.get(object);
                    if(o!=null&&!o.equals("")){
                        String string = (String)o;
                        if(b){
                            string = string.replaceAll(" ","");
                        }else {
                            string=string.trim();
                        }
                        //相当于调用了set方法设置属性
                        field.set(object,string);
                    }
                } catch (IllegalAccessException e) {
                    e.printStackTrace();
                }
            }
        }
        return object;
    }
}

复写后的效果是增加了比较对象的属性值，如果属性值是其他对象的话，其他对象也需要继承BaseEntity

 

属性全是基本/包装类型测试

 

属性包含其他Bean测试

        属性bean不继承BaseEntity        false

        属性bean继承BaseEntity        true

 

 

最后把测试的bean顺便贴上

package com.shinedata.service;

import com.shinedata.entity.base.BaseEntity;
import lombok.Data;

/**
 * @ClassName TestEntity
 * @Author yupanpan
 * @Date 2019/9/25 15:09
 */
@Data
public class TestEntity extends BaseEntity {
    private static final long serialVersionUID = -1063888689805742362L;

    private String name;
    private Integer age;
    private int num;

    private EmployeeEntity employeeEntity;
}

 

package com.shinedata.service;

import com.shinedata.entity.base.BaseEntity;
import lombok.Data;

/**
 * @ClassName EmployeeEntity
 * @Author yupanpan
 * @Date 2019/9/26 15:58
 */
@Data
public class EmployeeEntity extends BaseEntity {

    private static final long serialVersionUID = 8186300376983220453L;
    private String name;
    private Integer deptId;
}

 

转载：https://blog.csdn.net/ypp91zr/article/details/101368827