java - 查询方法参数转换异常

Question

我正在尝试使用 spring-boot-starter-data-rest 通过 REST 访问 JPA 数据。 我想使用与 CrudRepository 不同的方法。但框架响应以下异常:

exception is org.springframework.data.repository.support.QueryMethodParameterConversionException: Failed to convert Brazil into hello.Country!] with root cause
org.springframework.core.convert.ConverterNotFoundException: No converter found capable of converting from type [java.lang.String] to type [@org.springframework.data.repository.query.Param hello.Country]

端点

http://localhost:8080/rest/cities/search/findByCountry?name=Brazil

CityRepository.java

@RepositoryRestResource(collectionResourceRel = "cities", path = "cities")
public interface  CityRepository extends CrudRepository<City, Long> {

    List<City> findByCountry(@Param("name") Country country);

}

City.java

@JsonIgnoreProperties({"hibernateLazyInitializer", "handler"})
@Entity
@Table(name = "City")
public class City implements Serializable {

    private static final long serialVersionUID = 1L;

    @Id
    @GeneratedValue(strategy=GenerationType.AUTO)
    @JsonInclude(value=Include.ALWAYS)
    private long id;

    @NotNull
    @Column(name="name")
    private String name;

    @ManyToOne(fetch = FetchType.LAZY)
    @JoinColumn(name = "country_id")
    @Embedded
    private Country country;

    protected City() {}

    public City(long id, String nome) {
        this.id = id;
        this.name = nome;
    }    

    public Country getCountry() {
        return country;
    }

Country.java

@JsonIgnoreProperties({"hibernateLazyInitializer", "handler"})
@Entity
public class Country implements Serializable {

    private static final long serialVersionUID = 1L;

    @Id
    @GeneratedValue(strategy=GenerationType.AUTO)
    private long id;

    @NotNull
    @Column(name = "name")
    private String name;

    @OneToMany(fetch = FetchType.LAZY, mappedBy="country")
    private Set<City> cities;        

    protected Country() {}

    public Country(long id, String nome) {
        this.id = id;
        this.name = nome;
    }

当我打电话http://localhost:8080/rest/cities/时，我正常得到城市列表。我将 configureRepositoryRestConfiguration 设置为 config.setBasePath("/rest");

Answer 1

java.lang.String != hello.Country

根据文档，我们需要:

1. Use ResponseBody with consumes

2. 或者从 String 创建对象，如REST hello world example