Java遍历属性将null转为空或0

谁践踏了优雅 2023-06-24 04:59 3阅读 0赞

1、创建测试类（BeanTest1.java）

package com.jeff;
    
    import java.lang.reflect.Field;
    import java.util.Date;
    
    import com.jeff.entity.Student;
    
    public class BeanTest1 { 
    
    	public static void main(String[] args) throws Exception { 
    		Student s = new Student();
    		s.setLoginName("Jeff");
    		s.setSex(1);
    		s.setCreateTime(new Date());
    		System.out.println("转换前：" + s.toString());
    		s = reflect(s);
    		System.out.println("转换后：" + s.toString());
    	}
    
    	/** * * @description: 遍历属性将null转为""或0 * @author: Jeff * @date: 2019年12月20日 * @param <T> * @param o * @return * @throws Exception */
    	private static <T> T reflect(T o) throws Exception { 
    		Class<? extends Object> cls = o.getClass();
    		Field[] fields = cls.getDeclaredFields();
    		for (int i = 0; i < fields.length; i++) { 
    			Field f = fields[i];
    			f.setAccessible(true);
    			System.out.println("属性名：" + f.getName() + "；属性值：" + f.get(o) + "；字段类型：" + f.getType());
    			if (f.getType() == String.class && f.get(o) == null) { 
    				f.set(o, "");
    			}
    			if (f.getType() == Integer.class && f.get(o) == null) { 
    				f.set(o, 0);
    			}
    		}
    		return o;
    	}
    
    }

2、控制台输出结果  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80NTczOTcyMA_size_16_color_FFFFFF_t_70]

[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80NTczOTcyMA_size_16_color_FFFFFF_t_70]: https://img-blog.csdnimg.cn/2019122020382573.png?x-oss-process=image/watermark,type_ZmFuZ3poZW5naGVpdGk,shadow_10,text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80NTczOTcyMA==,size_16,color_FFFFFF,t_70