在Spring MVC中，JSON类型的数据如何交互？请按照返回实体对象、ArrayList集合、Map<String，Object>集合以及List<Map<Spring，Object>>集合举例说明

在Spring MVC中，JSON类型的数据可以通过@ResponseBody注解返回到前端。

1. 返回实体对象：

@RequestMapping(value = "/getEntity", method = RequestMethod.GET)
@ResponseBody
public User getEntity() {
    User user = new User();
    user.setId(1);
    user.setName("Tom");
    user.setAge(20);
    return user;
}

2. 返回ArrayList集合：

@RequestMapping(value = "/getList", method = RequestMethod.GET)
@ResponseBody
public List<User> getList() {
    List<User> userList = new ArrayList<User>();
    User user1 = new User();
    user1.setId(1);
    user1.setName("Tom");
    user1.setAge(20);
    userList.add(user1);
    User user2 = new User();
    user2.setId(2);
    user2.setName("Jerry");
    user2.setAge(22);
    userList.add(user2);
    return userList;
}

3. 返回Map<String,Object>集合：

@RequestMapping(value = "/getMap", method = RequestMethod.GET)
@ResponseBody
public Map<String,Object> getMap() {
    Map<String,Object> map = new HashMap<String,Object>();
    map.put("id", 1);
    map.put("name", "Tom");
    map.put("age", 20);
    return map;
}

4. 返回List<Map<String,Object>>集合：

@RequestMapping(value = "/getListMap", method = RequestMethod.GET)
@ResponseBody
public List<Map<String,Object>> getListMap() {
    List<Map<String,Object>> list = new ArrayList<Map<String,Object>>();
    Map<String,Object> map1 = new HashMap<String,Object>();
    map1.put("id", 1);
    map1.put("name", "Tom");
    map1.put("age", 20);
    list.add(map1);
    Map<String,Object> map2 = new HashMap<String,Object>();
    map2.put("id", 2);
    map2.put("name", "Jerry");
    map2.put("age", 22);
    list.add(map2);
    return list;
}

以上就是返回不同类型的JSON数据的示例。