Object & Map 的相互转换

本是古典何须时尚 2024-03-23 19:25 103阅读 0赞

**学生业务对象定义：Student**

Student student = new Student();
    student.setId(1L);
    student.setName("令狐冲")
    student.setAge(10)

## **第一种：通过Alibaba Fastjson实现** ##

### **pom.xml 文件依赖** ###

<dependency>
        <groupId>com.alibaba</groupId>
        <artifactId>fastjson</artifactId>
        <version>1.2.66</version>
    </dependency>

### 代码实现 ###

//Object转Map
    Map map = JSONObject.parseObject(JSONObject.toJSONString(student), Map.class);
    Map<String,Object> map = JSONObject.parseObject(JSON.toJSONString(student));
    //Map转Object
    Student s1 = JSON.parseObject(JSON.toJSONString(map), Student.class);
    Student s2 = JSONObject.toJavaObject(JSON.toJSONString(map), Student.class);

## **第二种：通过SpringBoot自带 Jackso实现** ##

一般情况下我们引入MVC，MVC里面帮我们引入了**Jackso**依赖

### 导入依赖 ###

<dependency>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-starter-web</artifactId>
            </dependency>

![96e5316614bb46069aa6b917159eb0c7.png][]

最终的依赖：

![aed5d966cafb4cafbc2d73455da586e6.png][]

### 代码实现 ###

ObjectMapper mapper = new ObjectMapper();
    //对象转map
    Map m = mapper.readValue(mapper.writeValueAsString(student), Map.class);
    //map转对象
    Student s = mapper.readValue(mapper.writeValueAsString(m), Student.class);

## **第三种：通过Apache common Bean工具类实现** ##

### pom.xml文件依赖 ###

<dependency>
        <groupId>commons-beanutils</groupId>
        <artifactId>commons-beanutils</artifactId>
        <version>1.9.3</version>
    </dependency>

### 代码实现 ###

#使用org.apache.commons.beanutils.BeanMap进行转换，实现Bean转Map
    Map<String, Object> map = new org.apache.commons.beanutils.BeanMap(student);
     
    #使用org.apache.commons.beanutils.BeanUtils将map转为对象
    BeanUtils.populate(student, map);

## **第四种： 通过反射实现** ##

### 通过反射实现Bean 转Map ###

//Object转Map
    public static Map<String, Object> getObjectToMap(Object obj) throws IllegalAccessException {
        Map<String, Object> map = new LinkedHashMap<String, Object>();
        Class<?> clazz = obj.getClass();
        System.out.println(clazz);
        for (Field field : clazz.getDeclaredFields()) {
            field.setAccessible(true);
            String fieldName = field.getName();
            Object value = field.get(obj);
            if (value == null){
                value = "";
            }
            map.put(fieldName, value);
        }
        return map;
    }

### 通过反射实现Map转Bean ###

//Map转Object
    public static Object mapToObject(Map<Object, Object> map, Class<?> beanClass) throws Exception {
        if (map == null)
            return null;
        Object obj = beanClass.newInstance();
        Field[] fields = obj.getClass().getDeclaredFields();
        for (Field field : fields) {
            int mod = field.getModifiers();
            if (Modifier.isStatic(mod) || Modifier.isFinal(mod)) {
                continue;
            }
            field.setAccessible(true);
            if (map.containsKey(field.getName())) {
                field.set(obj, map.get(field.getName()));
            }
        }
        return obj;
    }

[96e5316614bb46069aa6b917159eb0c7.png]: https://image.dandelioncloud.cn/pgy_files/images/2024/03/14/75388359cbfc4763833c5bdca2c097c7.png
[aed5d966cafb4cafbc2d73455da586e6.png]: https://image.dandelioncloud.cn/pgy_files/images/2024/03/14/44f95c672dd24a9d8af6c56d1f984ffe.png