如何在Java中實現對象和Map之間的轉換
作者：一安
本文將介紹幾種不同的方法來實現Java對象和Map之間的相互轉換，選擇哪種方法取決于項目的具體需求和個人偏好。
在Java開發中，經常需要將Java對象轉換成Map，或者反過來將Map轉換成Java對象。這種轉換在很多場景下都非常有用，比如在序列化和反序列化過程中、在數據傳輸和持久化時、或者在進行對象屬性的批量操作時。
本文將介紹幾種不同的方法來實現Java對象和Map之間的相互轉換，選擇哪種方法取決于項目的具體需求和個人偏好。
方法一：使用Spring Framework的ReflectionUtils
Bean轉為Map
Person person = new Person();
person.setAge(18);
person.setOpenid("123456");
person.setName("一安");
person.setSubName("公眾號");
System.out.println(bean2Map(person));
System.out.println(bean2Map2(person));
public static Map<String, Object> bean2Map(Object object) {
Map<String, Object> map = new HashMap<>();
ReflectionUtils.doWithFields(object.getClass(), field -> {
field.setAccessible(true);
Object value = ReflectionUtils.getField(field, object);
if (value != null) {
map.put(field.getName(), value);
}
});
return map;
}
public static Map<String, Object> bean2Map2(Object object) {
Map<String, Object> map = new HashMap<>();
Class<?> clazz = object.getClass();
Field[] fields = clazz.getDeclaredFields();
for (Field field : fields) {
field.setAccessible(true);
try {
Object value = field.get(object);
if (value != null) {
map.put(field.getName(), value);
}
} catch (IllegalAccessException e) {
throw new RuntimeException("Error accessing field: " + field.getName(), e);
}
}
return map;
}Map轉為Bean
Map<String, Object> map = new HashMap();
map.put("age", 18);
map.put("openid", "123456");
map.put("name", "一安");
map.put("subName", "公眾號");
System.out.println(map2Bean(map, Person.class));
System.out.println(map2Bean2(map, Person.class));
public static <T> T map2Bean(Map<String, Object> map, Class<T> clazz) throws IllegalAccessException, InstantiationException {
T instance = clazz.newInstance();
ReflectionUtils.doWithFields(clazz, field -> {
field.setAccessible(true);
if (map.containsKey(field.getName())) {
ReflectionUtils.setField(field, instance, map.get(field.getName()));
}
});
return instance;
}
public static <T> T map2Bean2(Map<String, Object> map, Class<T> clazz) throws IllegalAccessException, InstantiationException {
T instance = clazz.newInstance();
Field[] fields = clazz.getDeclaredFields();
for (Field field : fields) {
field.setAccessible(true);
if (map.containsKey(field.getName())) {
field.set(instance, map.get(field.getName()));
}
}
return instance;
}方法二：使用Hutool工具
<dependency>
<groupId>cn.hutool</groupId>
<artifactId>hutool-all</artifactId>
<version>5.8.5</version>
</dependency>Bean轉為Map
Person person = new Person();
person.setAge(18);
person.setOpenid("123456");
person.setName("一安");
person.setSubName("公眾號");
Map<String, Object> map = BeanUtil.beanToMap(person);Map轉為Bean
Map<String, Object> map = new HashMap();
map.put("age", 18);
map.put("openid", "123456");
map.put("name", "一安");
map.put("subName", "公眾號");
Person person = BeanUtil.toBean(map, Person.class);方法三：使用Jackson工具
Bean轉為Map
Person person = new Person();
person.setAge(18);
person.setOpenid("123456");
person.setName("一安");
person.setSubName("公眾號");
System.out.println(bean2Map(person));
public static Map<String, Object> bean2Map(Object object) {
ObjectMapper objectMapper = new ObjectMapper();
return objectMapper.convertValue(object, new TypeReference<Map<String, Object>>() {
});
}Map轉為Bean
Map<String, Object> map = new HashMap();
map.put("age", 18);
map.put("openid", "123456");
map.put("name", "一安");
map.put("subName", "公眾號");
System.out.println(map2Bean(map, Person.class));
public static <T> T map2Bean(Map<String, Object> map, Class<T> clazz){
ObjectMapper objectMapper = new ObjectMapper();
return objectMapper.convertValue(map, clazz);
}方法四：使用Apache Commons Lang的BeanUtils
<dependency>
<groupId>org.apache.commons</groupId>
<artifactId>commons-lang3</artifactId>
<version>3.12.0</version>
</dependency>Bean轉為Map
Person person = new Person();
person.setAge(18);
person.setOpenid("123456");
person.setName("一安");
person.setSubName("公眾號");
System.out.println(bean2Map(person));
public static Map<String, String> bean2Map(Object object) {
try {
return BeanUtils.describe(object);
} catch (Exception e) {
throw new RuntimeException("Error converting object to map: " + e.getMessage(), e);
}
}Map轉為Bean
Map<String, Object> map = new HashMap();
map.put("age", 18);
map.put("openid", "123456");
map.put("name", "一安");
map.put("subName", "公眾號");
System.out.println(map2Bean(map, Person.class));
public static <T> T map2Bean(Map<String, ?> map, Class<T> clazz) {
try {
T instance = clazz.newInstance();
BeanUtils.populate(instance, map);
return instance;
} catch (Exception e) {
throw new RuntimeException("Error converting map to object: " + e.getMessage(), e);
}
}方法五：使用fastjson工具
<dependency>
<groupId>com.alibaba</groupId>
<artifactId>fastjson</artifactId>
<version>1.2.83</version>
</dependency>Bean轉為Map
Person person = new Person();
person.setAge(18);
person.setOpenid("123456");
person.setName("一安");
person.setSubName("公眾號");
System.out.println(JSONObject.parseObject(JSONObject.toJSONString(person)));Map轉為Bean
Map<String, Object> map = new HashMap();
map.put("age", 18);
map.put("openid", "123456");
map.put("name", "一安");
map.put("subName", "公眾號");
System.out.println(JSONObject.parseObject(JSONObject.toJSONString(map), Person.class));責任編輯：武曉燕
來源：
一安未來
