Springboot内置的工具类之ObjectUtils

- 日理万妓 2024-03-31 17:53 121阅读 0赞

在实际业务开发中，有时候经常需要判断对象是否为空、数组是否为空、两个对象是否相等，数组中是否包含某个元素，往数组中追加元素等这些操作，每次都手写太麻烦，然后很多人的选择是封装成util工具类，实际上类似这些东西，如果项目使用了spring的框架，根本不需要封装，org.springframework.util.ObjectUtils类中已经封装好了各种的静态方法供你调用。那就一起来学习一下吧。

## org.springframework.util.ObjectUtils ##

### boolean isEmpty(Object obj) ###

作用：

obj可以是普通对象，也可以是普通数组，如果obj为空（null或is empty），则返回true；否则返回false;

### boolean isEmpty(Object\[\] array) ###

作用：

array参数是数组，如果数组array为空（null或is empty），则返回true；否则返回false;

### boolean isArray(Object obj) ###

作用：

参数是对象，如果参数对象obj是数组，则返回true；否则返回false;

### boolean containsElement(Object\[\] array, Object element) ###

作用：

参数array为目标数组，参数element为普通待判断的元素，如果目标数组array中包含元素element，则返回true; 否则返回false;

### boolean nullSafeEquals(Object o1, Object o2) ###

作用：

参数为o1、o2为普通对象，可以是数字、字符、对象、数组，如果o1与o2相等，则返回true;否则返回false;

### String nullSafeToString(Object obj) ###

作用：

参数obj可以是普通对象、布尔类型、byte类型、字符类型、浮点型、双精度浮点型、整型、长整型、短整型其人中一种

### A\[\] addObjectToArray(A\[\] array, O obj) ###

作用：

参数array为目标数组，参数obj为待添加元素，向参数数组array的末尾追加新元素obj，并返回一个新数组;

@Test
    public void objectUtilsTest(){
        Employee employee = new Employee();
        employee.setRealName("zhangsan");
        boolean empty = ObjectUtils.isEmpty(employee);
        System.out.println("isEmpty:"+empty);
        Employee[] employees={employee};
        boolean empty1 = ObjectUtils.isEmpty(employees);
        System.out.println("isEmpty(arrar):"+empty1);
        boolean array = ObjectUtils.isArray(employees);
        System.out.println("isArray:"+array);
        Employee tar = new Employee();
        tar.setRealName("zhangsan");
        boolean b = ObjectUtils.containsElement(employees, tar);
        System.out.println("containsElement:"+b);
        boolean b1 = ObjectUtils.nullSafeEquals(employee, tar);
        System.out.println("nullSafeEquals:"+b1);
        Employee lisi = new Employee();
        lisi.setRealName("lisi");
        Employee[] employees1 = ObjectUtils.addObjectToArray(employees, lisi);
        System.out.println("addObjectToArray:"+employees1);
        String string = ObjectUtils.nullSafeToString(employees1);
        System.out.println("nullSafeToString:"+string);
    }

## 总结 ##

org.springframework.util.ObjectUtils类中有很多已经封装好的静态方法，平时用到的里面基本都有，下面是整体的UML类图，这里只是分享其中用互频率非常高的7种，有兴趣的小伙伴可以继续深入探索下去。

![f8c6e025b3bc42adaa2d5ef4e6e8b52c.png][]

> Springboot扩展点系列实现方式、工作原理集合：
> 
> [Springboot扩展点之ApplicationContextInitializer][Springboot_ApplicationContextInitializer]
> 
> [Springboot扩展点之BeanDefinitionRegistryPostProcessor][Springboot_BeanDefinitionRegistryPostProcessor]
> 
> [Springboot扩展点之BeanFactoryPostProcessor][Springboot_BeanFactoryPostProcessor]
> 
> [Springboot扩展点之BeanPostProcessor][Springboot_BeanPostProcessor]
> 
> [Springboot扩展点之InstantiationAwareBeanPostProcessor][Springboot_InstantiationAwareBeanPostProcessor]
> 
> [Springboot扩展点之SmartInstantiationAwareBeanPostProcessor][Springboot_SmartInstantiationAwareBeanPostProcessor]
> 
> [Springboot扩展点之ApplicationContextAwareProcessor][Springboot_ApplicationContextAwareProcessor]
> 
> [Springboot扩展点之@PostConstruct][Springboot_PostConstruct]
> 
> [Springboot扩展点之InitializingBean][Springboot_InitializingBean]
> 
> [Springboot扩展点之DisposableBean][Springboot_DisposableBean]
> 
> [Springboot扩展点之SmartInitializingSingleton][Springboot_SmartInitializingSingleton]
> 
> Springboot核心功能工作原理：
> 
> [Springboot实现调度任务的工作原理][Springboot]
> 
> [Springboot事件监听机制的工作原理][Springboot 1]

[f8c6e025b3bc42adaa2d5ef4e6e8b52c.png]: https://image.dandelioncloud.cn/pgy_files/images/2024/03/31/63ab64dfa23c44ed9064cb4e99c7ba38.png
[Springboot_ApplicationContextInitializer]: https://blog.csdn.net/fox9916/article/details/128522598
[Springboot_BeanDefinitionRegistryPostProcessor]: https://blog.csdn.net/fox9916/article/details/128538625
[Springboot_BeanFactoryPostProcessor]: https://blog.csdn.net/fox9916/article/details/128823328
[Springboot_BeanPostProcessor]: https://blog.csdn.net/fox9916/article/details/128917992
[Springboot_InstantiationAwareBeanPostProcessor]: https://blog.csdn.net/fox9916/article/details/128941464
[Springboot_SmartInstantiationAwareBeanPostProcessor]: https://blog.csdn.net/fox9916/article/details/128976944
[Springboot_ApplicationContextAwareProcessor]: https://blog.csdn.net/fox9916/article/details/128990305
[Springboot_PostConstruct]: https://blog.csdn.net/fox9916/article/details/128998846
[Springboot_InitializingBean]: https://blog.csdn.net/fox9916/article/details/129016083
[Springboot_DisposableBean]: https://blog.csdn.net/fox9916/article/details/129026156?spm=1001.2014.3001.5501
[Springboot_SmartInitializingSingleton]: https://blog.csdn.net/fox9916/article/details/129042652
[Springboot]: https://blog.csdn.net/fox9916/article/details/128483069
[Springboot 1]: https://blog.csdn.net/fox9916/article/details/128225155