在生成的 Restful Web 服务中获取更多查询

Question

我使用 netbeans 创建一个 Restful Web 服务，我只需指定数据库和 netbeans 来创建所有内容。在子资源中，我只有 4 个 URI：

converter.city (http://localhost:8080/Data/resources/converter.city)

converter.city/{id}(http://localhost:8080/Data/resources/converter.city/{id})

converter.city/{from}/{to(http://localhost:8080/Data/resources/converter.city/{from}/{to})

converter.city/count(http://localhost:8080/Data/resources/converter.city/count)

这是生成的代码，观看第一部分

@Entity
@Table(name = "City")
@XmlRootElement
@NamedQueries({
    @NamedQuery(name = "City.findAll", query = "SELECT c FROM City c"),
    @NamedQuery(name = "City.findById", query = "SELECT c FROM City c WHERE c.id = :id"),
    @NamedQuery(name = "City.findByName", query = "SELECT c FROM City c WHERE c.name = :name"),
    @NamedQuery(name = "City.findByCountryCode", query = "SELECT c FROM City c WHERE c.countryCode = :countryCode"),
    @NamedQuery(name = "City.findByDistrict", query = "SELECT c FROM City c WHERE c.district = :district"),
    @NamedQuery(name = "City.findByPopulation", query = "SELECT c FROM City c WHERE c.population = :population")})
public class City implements Serializable {
    private static final long serialVersionUID = 1L;
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    @Basic(optional = false)
    @NotNull
    @Column(name = "ID")
    private Integer id;
    @Basic(optional = false)
    @NotNull
    @Size(min = 1, max = 35)
    @Column(name = "Name")
    private String name;
    @Basic(optional = false)
    @NotNull
    @Size(min = 1, max = 3)
    @Column(name = "CountryCode")
    private String countryCode;
    @Basic(optional = false)
    @NotNull
    @Size(min = 1, max = 20)
    @Column(name = "District")
    private String district;
    @Basic(optional = false)
    @NotNull
    @Column(name = "Population")
    private int population;

    public City() {
    }

    public City(Integer id) {
        this.id = id;
    }

    public City(Integer id, String name, String countryCode, String district, int population) {
        this.id = id;
        this.name = name;
        this.countryCode = countryCode;
        this.district = district;
        this.population = population;
    }

    public Integer getId() {
        return id;
    }

    public void setId(Integer id) {
        this.id = id;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public String getCountryCode() {
        return countryCode;
    }

    public void setCountryCode(String countryCode) {
        this.countryCode = countryCode;
    }

    public String getDistrict() {
        return district;
    }

    public void setDistrict(String district) {
        this.district = district;
    }

    public int getPopulation() {
        return population;
    }

    public void setPopulation(int population) {
        this.population = population;
    }

    @Override
    public int hashCode() {
        int hash = 0;
        hash += (id != null ? id.hashCode() : 0);
        return hash;
    }

    @Override
    public boolean equals(Object object) {
        // TODO: Warning - this method won't work in the case the id fields are not set
        if (!(object instanceof City)) {
            return false;
        }
        City other = (City) object;
        if ((this.id == null && other.id != null) || (this.id != null && !this.id.equals(other.id))) {
            return false;
        }
        return true;
    }

    @Override
    public String toString() {
        return "converter.City[ id=" + id + " ]";
    }

在生成的代码中有很多查询，其中一个我感兴趣

 @NamedQuery(name = "City.findByCountryCode", query = "SELECT c FROM City c WHERE c.countryCode = :countryCode")    

我如何使用 City.findByCountryCode ？

Answer 1

Query query = em.createNamedQuery("City.findByCountryCode")
    .setParameter("countryCode", yourCountryCode);