我需要在postgres中使用spring data jpa将实体类的两列Map为json.在阅读了多个stackoverflow post和baeldung post之后，
How to map a map JSON column to Java Object with JPA
https://www.baeldung.com/hibernate-persist-json-object
我做了如下配置。但是，我遇到错误“错误：列“headers”的类型为json，但表达式的类型为字符变量
请提供一些解决此问题的方法。
我有一个如下的实体类

@Entity
@Data
@SuperBuilder
@NoArgsConstructor
@AllArgsConstructor
public class Task {
    @Id
    @GeneratedValue(strategy = IDENTITY)
    private Integer id;
    
    private String url;
    private String httpMethod;

    @Convert(converter = HashMapConverter.class)
    @Column(columnDefinition = "json")
    private Map<String, String> headers;

    @Convert(converter = HashMapConverter.class)
    @Column(columnDefinition = "json")
    private Map<String, String> urlVariables;
}

我已经创建了一个测试类来测试实体是否持久化。在运行此junit时，下面的测试用例失败，错误如下

@SpringBootTest
class TaskRepositoryTest {

    private static Task randomTask = randomTask();

    @Autowired
    private TaskRepository taskRepository;

    @BeforeEach
    void setUp() {
        taskRepository.deleteAll();
        taskRepository.save(randomTask);
    }

    public static Task randomTask() {
        return randomTaskBuilder().build();
    }

    public static TaskBuilder randomTaskBuilder() {
        Map<String,String> headers = new HashMap<>();
        headers.put(randomAlphanumericString(10),randomAlphanumericString(10));

        Map<String,String> urlVariables = new HashMap<>();
        urlVariables.put(randomAlphanumericString(10),randomAlphanumericString(10));

        return builder()
                .id(randomPositiveInteger())
                .httpMethod(randomAlphanumericString(10))
                .headers(headers)
                .urlVariables(urlVariables)
                .url(randomAlphanumericString(10)));
    }
}

使用liquibase，我已经在postgres DB中创建了表，我可以看到列的数据类型为json。

databaseChangeLog:
  - changeSet:
      id: 1
      author: abc
      changes:
        - createTable:
            tableName: task
            columns:
              - column:
                  name: id
                  type: int
                  autoIncrement: true
                  constraints:
                    primaryKey: true
              - column:
                  name: url
                  type: varchar(250)
                  constraints:
                    nullable: false
                    unique: true
              - column:
                  name: http_method
                  type: varchar(50)
                  constraints:
                    nullable: false
              - column:
                  name: headers
                  type: json
              - column:
                  name: url_variables
                  type: json
      rollback:
        - dropTable:
            tableName: task