String collectionJson = "[ {\"school" : \"xxx\", ... },  {\"student" : \"yyy\", ...} ]";
List<JavaType> javaTypeList = new ArrayList<>();
javaTypeList.add(schoolJavaType);
javaTypeList.add(studentJavaType);
// like fastjson#parseArray(collectionJsonString, arrayOfJavaLangReflectType);
List<Object> objectList = objectMapper.parseListByType(collectionJson, javaTypeList);