JSON解析錯誤：無法構造`com.example.greetapp.domain.User`的實例

Question

我正在使用JHipster，並且正在運行以下curl命令：

POST / api / gang-users

與身體：

{
    "role": "member",
    "gang": "3",
    "user": "1"
}

但我收到以下錯誤：

JSON解析錯誤：無法構造com.getgreetapp.greetapp.domain.User實例（盡管至少存在一個Creator）：沒有要從字符串值（'1'）反序列化的字符串參數構造函數/工廠方法； 嵌套異常是com.fasterxml.jackson.databind.exc.MismatchedInputException：無法構造com.getgreetapp.greetapp.domain.User實例（盡管至少存在一個Creator）：沒有用於從String值反序列化的String-argument構造函數/工廠方法（'1'）\\ n在[來源：（PushbackInputStream）; 第4行，第10列]（通過參考鏈：com.getgreetapp.greetapp.domain.GangUser [\\“ user \\”]）

GangUserResource createGangUser

@PostMapping("/gang-users")
    @Timed
    public ResponseEntity<GangUser> createGangUser(@Valid @RequestBody GangUser gangUser) throws URISyntaxException {
        log.debug("REST request to save GangUser : {}", gangUser);
        if (gangUser.getId() != null) {
            throw new BadRequestAlertException("A new gangUser cannot already have an ID", ENTITY_NAME, "idexists");
        }
        User user = userRepository.findById(gangUser.getUser());
        GangUser result = gangUserRepository.save(gangUser);
        return ResponseEntity.created(new URI("/api/gang-users/" + result.getId()))
            .headers(HeaderUtil.createEntityCreationAlert(ENTITY_NAME, result.getId().toString()))
            .body(result);
    }

幫派用戶

package com.getgreetapp.greetapp.domain;

import com.fasterxml.jackson.annotation.JsonIgnoreProperties;
import org.hibernate.annotations.Cache;
import org.hibernate.annotations.CacheConcurrencyStrategy;

import javax.persistence.*;
import javax.validation.constraints.*;

import java.io.Serializable;
import java.util.Objects;

/**
 * A GangUser.
 */
@Entity
@Table(name = "gang_user")
@Cache(usage = CacheConcurrencyStrategy.NONSTRICT_READ_WRITE)
public class GangUser implements Serializable {

    private static final long serialVersionUID = 1L;

    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Long id;

    @NotNull
    @Column(name = "jhi_role", nullable = false)
    private String role;

    @ManyToOne
    private Gang gang;

    @ManyToOne
    private User user;

    public GangUser() {

    }

    public GangUser(String role, Gang gang, User user)
    {
        this.role = role;
        this.gang = gang;
        this.user = user;
    }

    // jhipster-needle-entity-add-field - JHipster will add fields here, do not remove
    public Long getId() {
        return id;
    }

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

    public String getRole() {
        return role;
    }

    public GangUser role(String role) {
        this.role = role;
        return this;
    }

    public void setRole(String role) {
        this.role = role;
    }

    public Gang getGang() {
        return gang;
    }

    public GangUser gang(Gang gang) {
        this.gang = gang;
        return this;
    }

    public void setGang(Gang gang) {
        this.gang = gang;
    }

    public User getUser() {
        return user;
    }

    public GangUser user(User user) {
        this.user = user;
        return this;
    }

    public void setUser(User user) {
        this.user = user;
    }
    // jhipster-needle-entity-add-getters-setters - JHipster will add getters and setters here, do not remove

    @Override
    public boolean equals(Object o) {
        if (this == o) {
            return true;
        }
        if (o == null || getClass() != o.getClass()) {
            return false;
        }
        GangUser gangUser = (GangUser) o;
        if (gangUser.getId() == null || getId() == null) {
            return false;
        }
        return Objects.equals(getId(), gangUser.getId());
    }

    @Override
    public int hashCode() {
        return Objects.hashCode(getId());
    }

    @Override
    public String toString() {
        return "GangUser{" +
            "id=" + getId() +
            ", role='" + getRole() + "'" +
            "}";
    }
}

用戶

package com.getgreetapp.greetapp.domain;

import com.getgreetapp.greetapp.config.Constants;

import com.fasterxml.jackson.annotation.JsonIgnore;
import org.apache.commons.lang3.StringUtils;
import org.hibernate.annotations.BatchSize;
import org.hibernate.annotations.Cache;
import org.hibernate.annotations.CacheConcurrencyStrategy;
import javax.validation.constraints.Email;

import javax.persistence.*;
import javax.validation.constraints.NotNull;
import javax.validation.constraints.Pattern;
import javax.validation.constraints.Size;
import java.io.Serializable;
import java.util.HashSet;
import java.util.Locale;
import java.util.Objects;
import java.util.Set;
import java.time.Instant;

/**
 * A user.
 */
@Entity
@Table(name = "jhi_user")
@Cache(usage = CacheConcurrencyStrategy.NONSTRICT_READ_WRITE)
public class User extends AbstractAuditingEntity implements Serializable {

    private static final long serialVersionUID = 1L;

    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Long id;

    @NotNull
    @Pattern(regexp = Constants.LOGIN_REGEX)
    @Size(min = 1, max = 50)
    @Column(length = 50, unique = true, nullable = false)
    private String login;

    @JsonIgnore
    @NotNull
    @Size(min = 60, max = 60)
    @Column(name = "password_hash", length = 60, nullable = false)
    private String password;

    @Size(max = 50)
    @Column(name = "first_name", length = 50)
    private String firstName;

    @Size(max = 50)
    @Column(name = "last_name", length = 50)
    private String lastName;

    @Email
    @Size(min = 5, max = 254)
    @Column(length = 254, unique = true)
    private String email;

    @NotNull
    @Column(nullable = false)
    private boolean activated = false;

    @Size(min = 2, max = 6)
    @Column(name = "lang_key", length = 6)
    private String langKey;

    @Size(max = 256)
    @Column(name = "image_url", length = 256)
    private String imageUrl;

    @Size(max = 20)
    @Column(name = "activation_key", length = 20)
    @JsonIgnore
    private String activationKey;

    @Size(max = 20)
    @Column(name = "reset_key", length = 20)
    @JsonIgnore
    private String resetKey;

    @Column(name = "reset_date")
    private Instant resetDate = null;

    @JsonIgnore
    @ManyToMany
    @JoinTable(
        name = "jhi_user_authority",
        joinColumns = {@JoinColumn(name = "user_id", referencedColumnName = "id")},
        inverseJoinColumns = {@JoinColumn(name = "authority_name", referencedColumnName = "name")})
    @Cache(usage = CacheConcurrencyStrategy.NONSTRICT_READ_WRITE)
    @BatchSize(size = 20)
    private Set<Authority> authorities = new HashSet<>();

    public User() {}

    public Long getId() {
        return id;
    }

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

    public String getLogin() {
        return login;
    }

    // Lowercase the login before saving it in database
    public void setLogin(String login) {
        this.login = StringUtils.lowerCase(login, Locale.ENGLISH);
    }

    public String getPassword() {
        return password;
    }

    public void setPassword(String password) {
        this.password = password;
    }

    public String getFirstName() {
        return firstName;
    }

    public void setFirstName(String firstName) {
        this.firstName = firstName;
    }

    public String getLastName() {
        return lastName;
    }

    public void setLastName(String lastName) {
        this.lastName = lastName;
    }

    public String getEmail() {
        return email;
    }

    public void setEmail(String email) {
        this.email = email;
    }

    public String getImageUrl() {
        return imageUrl;
    }

    public void setImageUrl(String imageUrl) {
        this.imageUrl = imageUrl;
    }

    public boolean getActivated() {
        return activated;
    }

    public void setActivated(boolean activated) {
        this.activated = activated;
    }

    public String getActivationKey() {
        return activationKey;
    }

    public void setActivationKey(String activationKey) {
        this.activationKey = activationKey;
    }

    public String getResetKey() {
        return resetKey;
    }

    public void setResetKey(String resetKey) {
        this.resetKey = resetKey;
    }

    public Instant getResetDate() {
        return resetDate;
    }

    public void setResetDate(Instant resetDate) {
        this.resetDate = resetDate;
    }

    public String getLangKey() {
        return langKey;
    }

    public void setLangKey(String langKey) {
        this.langKey = langKey;
    }

    public Set<Authority> getAuthorities() {
        return authorities;
    }

    public void setAuthorities(Set<Authority> authorities) {
        this.authorities = authorities;
    }

    @Override
    public boolean equals(Object o) {
        if (this == o) {
            return true;
        }
        if (o == null || getClass() != o.getClass()) {
            return false;
        }

        User user = (User) o;
        return !(user.getId() == null || getId() == null) && Objects.equals(getId(), user.getId());
    }

    @Override
    public int hashCode() {
        return Objects.hashCode(getId());
    }

    @Override
    public String toString() {
        return "User{" +
            "login='" + login + '\'' +
            ", firstName='" + firstName + '\'' +
            ", lastName='" + lastName + '\'' +
            ", email='" + email + '\'' +
            ", imageUrl='" + imageUrl + '\'' +
            ", activated='" + activated + '\'' +
            ", langKey='" + langKey + '\'' +
            ", activationKey='" + activationKey + '\'' +
            "}";
    }
}

幫派

package com.getgreetapp.greetapp.domain;

import org.hibernate.annotations.Cache;
import org.hibernate.annotations.CacheConcurrencyStrategy;

import javax.persistence.*;
import javax.validation.constraints.*;

import java.io.Serializable;
import java.math.BigDecimal;
import java.util.Objects;

/**
 * A Gang.
 */
@Entity
@Table(name = "gang")
@Cache(usage = CacheConcurrencyStrategy.NONSTRICT_READ_WRITE)
public class Gang implements Serializable {

    private static final long serialVersionUID = 1L;

    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Long id;

    @NotNull
    @Column(name = "name", nullable = false)
    private String name;

    @NotNull
    @Column(name = "description", nullable = false)
    private String description;

    @NotNull
    @Column(name = "longitude", precision = 10, scale = 2, nullable = false)
    private BigDecimal longitude;

    @NotNull
    @Column(name = "latitude", precision = 10, scale = 2, nullable = false)
    private BigDecimal latitude;

    @NotNull
    @Column(name = "membership_approval", nullable = false)
    private String membershipApproval;

    @NotNull
    @Column(name = "privacy", nullable = false)
    private String privacy;

    public Gang() {}

    // jhipster-needle-entity-add-field - JHipster will add fields here, do not remove
    public Long getId() {
        return id;
    }

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

    public String getName() {
        return name;
    }

    public Gang name(String name) {
        this.name = name;
        return this;
    }

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

    public String getDescription() {
        return description;
    }

    public Gang description(String description) {
        this.description = description;
        return this;
    }

    public void setDescription(String description) {
        this.description = description;
    }

    public BigDecimal getLongitude() {
        return longitude;
    }

    public Gang longitude(BigDecimal longitude) {
        this.longitude = longitude;
        return this;
    }

    public void setLongitude(BigDecimal longitude) {
        this.longitude = longitude;
    }

    public BigDecimal getLatitude() {
        return latitude;
    }

    public Gang latitude(BigDecimal latitude) {
        this.latitude = latitude;
        return this;
    }

    public void setLatitude(BigDecimal latitude) {
        this.latitude = latitude;
    }

    public String getMembershipApproval() {
        return membershipApproval;
    }

    public Gang membershipApproval(String membershipApproval) {
        this.membershipApproval = membershipApproval;
        return this;
    }

    public void setMembershipApproval(String membershipApproval) {
        this.membershipApproval = membershipApproval;
    }

    public String getPrivacy() {
        return privacy;
    }

    public Gang privacy(String privacy) {
        this.privacy = privacy;
        return this;
    }

    public void setPrivacy(String privacy) {
        this.privacy = privacy;
    }
    // jhipster-needle-entity-add-getters-setters - JHipster will add getters and setters here, do not remove

    @Override
    public boolean equals(Object o) {
        if (this == o) {
            return true;
        }
        if (o == null || getClass() != o.getClass()) {
            return false;
        }
        Gang gang = (Gang) o;
        if (gang.getId() == null || getId() == null) {
            return false;
        }
        return Objects.equals(getId(), gang.getId());
    }

    @Override
    public int hashCode() {
        return Objects.hashCode(getId());
    }

    @Override
    public String toString() {
        return "Gang{" +
            "id=" + getId() +
            ", name='" + getName() + "'" +
            ", description='" + getDescription() + "'" +
            ", longitude=" + getLongitude() +
            ", latitude=" + getLatitude() +
            ", membershipApproval='" + getMembershipApproval() + "'" +
            ", privacy='" + getPrivacy() + "'" +
            "}";
    }
}

Answer 1

以我的拙見，有幾件事情需要檢查。

首先，不建議使用相同的對象將數據存儲在數據庫中並響應請求。 數據對象可以是GangUser，User和Gang，而響應對象GangUserApi，UserApi和GangApi。 使用這種方法，您可以修改圖層而無需修改其他圖層。

其次，您的服務需要一個內部有用戶的GangUser。 用於將其存儲在數據庫中的同一用戶對象。 您只是發送一個String（“ 1”）而不是那里的一個對象。

一種快速的解決方案是修改JSON：

{
    "role": "member",
    "gang": "3",
    "user": {
        "id":"1"
    }
}

但我想知道您是否了解正在發生的事情。 這比給您快速解決方案更重要。

干杯。