JsonException没有分配_valueDeserializer

Question

我有一个带有某些Spring Crud存储库的经典Spring Web应用程序。

我试图将我的实体保存在经典的角度形式内，并且随机出现此错误：

.w.s.m.s.DefaultHandlerExceptionResolver : Failed to read HTTP message: org.springframework.http.converter.HttpMessageNotReadableException: Could not read document: No _valueDeserializer assigned
at [Source: java.io.PushbackInputStream@11936b0f; line: 1, column: 19] (through reference chain: com.adeo.volt.domain.HalfFlow["exchange"]->com.adeo.volt.domain.Exchange["id"]); nested exception is com.fasterxml.jackson.databind.JsonMappingException: No _valueDeserializer assigned
at [Source: java.io.PushbackInputStream@11936b0f; line: 1, column: 19] (through reference chain: com.adeo.volt.domain.HalfFlow["exchange"]->com.adeo.volt.domain.Exchange["id"])

这是我发送的杰森：

{
    "exchange": {
        "id": 305,
        "processExchange": [],
        "number": 305,
        "halfFlows": [],
        "name": "TEST2",
        "type": {
            "id": 2,
            "name": "real-time"
        },
        "technology": {
            "id": 1,
            "name": "ESB webMethods"
        },
        "exchangesObjectsExchanges": [{
            "id": 235,
            "exchangeObject": {
                "id": 180,
                "name": "TESTALEXX",
                "objectMeaning": "t",
                "internalReferent": "t",
                "internalBusinessReferent": null,
                "status": {
                    "id": 1,
                    "name": "Study In Progress"
                },
                "type": {
                    "id": 1,
                    "name": "Canonical"
                },
                "externalDocLink": null,
                "keywords": null,
                "qualityScore": null
            }
        }]
    },
    "way": {
        "id": 1,
        "name": "TO"
    },
    "halfFlowApplication": [{
        "application": {
            "id": 2,
            "name": "ADEXIOCRE2",
            "type": {
                "id": 1,
                "name": "INTERNAL"
            },
            "domain": {
                "id": 6,
                "name": "Logistics",
                "letter": "L"
            },
            "vendor": null,
            "projectName": null,
            "internalReferent": null,
            "groupApplicationType": {
                "id": 2,
                "name": "MULTI INSTANCE"
            },
            "halfFlowApplication": [{
                "id": 159
            }]
        }
    }],
    "halfFlowNumber": "L0305A",
    "name": "TEST2_TO_ADEXIOCRE2",
    "halfFlowBus": [{
        "bu": {
            "id": 10,
            "number": 10,
            "shortLabel": "BCIT",
            "longLabel": "BC ITALIE"
        },
        "id": null
    }],
    "connector": {
        "id": 4,
        "name": "FTP"
    }
}

这是我的课程：

Exchange.java

@Entity
public class Exchange {

@Id
@Column(unique = true, nullable = false)
@GenericGenerator(name = "ExchangeGenerator", strategy = "increment")
@GeneratedValue(generator = "ExchangeGenerator")
private Long id;

@Column(unique = true)
private String name;
private int number;
private long technologyId;
private long exchangeTypeId;

@OneToMany(mappedBy = "exchange")
private List<Halfflow> halfFlows;

public Exchange() {
}

/* Getters and Setters */
public Long getId() {
    return id;
}

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

public String getName() {
    return name;
}

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

public int getNumber() {
    return number;
}

public void setNumber(int number) {
    this.number = number;
}

public long getTechnologyId() {
    return technologyId;
}

public void setTechnologyId(long technologyId) {
    this.technologyId = technologyId;
}

public long getExchangeTypeId() {
    return exchangeTypeId;
}

public void setExchangeTypeId(Long exchangeTypeId) {
    this.exchangeTypeId = exchangeTypeId;
}

public void setExchangeTypeId(long exchangeTypeId) {
    this.exchangeTypeId = exchangeTypeId;
}

public List<Halfflow> getHalfFlows() {
    return halfFlows;
}

public void setHalfFlows(List<Halfflow> halfFlows) {
    this.halfFlows = halfFlows;
}

@Override
public String toString() {
    return "Exchange{" +
            "id=" + id +
            ", name='" + name + '\'' +
            ", number=" + number +
            ", technologyId=" + technologyId +
            '}';
}

}

Halfflow.java

@Entity
@Table(name="HALF_FLOW")
public class HalfFlow {

@Id
@Column(name = "ID", unique = true, nullable = false)
@GenericGenerator(name = "HalfflowGenerator", strategy = "increment")
@GeneratedValue(generator = "HalfflowGenerator")
@JsonProperty(value="id")
private Long id;

@Column(unique = true)
@JsonProperty(value="halfFlowNumber")
private String halfFlowNumber;

@JsonProperty(value="name")
private String name;

@ManyToOne
@JoinColumn(name = "WAY_ID")
private Way way;

@JsonProperty(value="externalDocLink")
private String externalDocLink;

@ManyToOne
@JoinColumn(name = "HALF_FLOW_MODE_ID")
@JsonProperty(value="mode")
private HalfFlowMode mode;

@JsonProperty(value="internalReferent")
private String internalReferent;

@JsonProperty(value="backupReferent")
private String backupReferent;

@ManyToOne
@JoinColumn(name = "DATA_FORMAT_ID")
@JsonProperty(value="format")
private DataFormat format;

@ManyToOne
@JoinColumn(name = "CONNECTOR_ID")
@JsonProperty(value="connector")
private Connector connector;

@ManyToOne
@JoinColumn(name = "CONFIDENTIALITY_ID")
@JsonProperty(value="confidentiality")
private Confidentiality confidentiality;

@ManyToOne
@JoinColumn(name = "INTEGRITY_ID")
@JsonProperty(value="integrity")
private Integrity integrity;

@ManyToOne
@JoinColumn(name="HALF_FLOW_AVAILABILITY_ID")
@JsonProperty(value="halfFlowAvailability")
private HalfFlowAvailability halfFlowAvailability;

@JsonIgnoreProperties(value = {"halfFlow"})
@OneToMany(mappedBy = "halfFlow")
@JsonProperty(value="halfFlowApplication")
private List<HalfFlowApplication> halfFlowApplication;

@OneToMany(mappedBy = "halfFlow")
@JsonProperty(value="halfFlowBus")
private List<HalfFlowBu> halfFlowBus;

@OneToMany(mappedBy = "halfFlow")
@JsonProperty(value="serviceHalfFlow")
private Set<ServiceHalfFlow> serviceHalfFlow;

@JsonIgnoreProperties(value = {"halfFlows"})
@ManyToOne
@JoinColumn(name="EXCHANGE_ID")
@JsonProperty(value="exchange")
private Exchange exchange;

@JsonProperty(value="bridge")
private boolean bridge;

public HalfFlow() {
}

public HalfFlow(String halfFlowNumber, String name) {
    this.halfFlowNumber = halfFlowNumber;
    this.name = name;
}

public HalfFlow(Long id, String halfFlowNumber, String name) {
    this.id = id;
    this.halfFlowNumber = halfFlowNumber;
    this.name = name;
}

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

    HalfFlow halfFlow = (HalfFlow) o;

    if (id != null ? !id.equals(halfFlow.id) : halfFlow.id != null) return false;
    return name != null ? name.equals(halfFlow.name) : halfFlow.name == null;

}

@Override
public int hashCode() {
    int result = id != null ? id.hashCode() : 0;
    result = 31 * result + (name != null ? name.hashCode() : 0);
    return result;
}

public Long getId() {
    return id;
}

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

public String getHalfFlowNumber() {
    return halfFlowNumber;
}

public void setHalfFlowNumber(String halfFlowNumber) {
    this.halfFlowNumber = halfFlowNumber;
}

public String getName() {
    return name;
}

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

public Way getWay() {
    return way;
}

public void setWay(Way way) {
    this.way = way;
}

public String getExternalDocLink() {
    return externalDocLink;
}

public void setExternalDocLink(String externalDocLink) {
    this.externalDocLink = externalDocLink;
}

public HalfFlowMode getMode() {
    return mode;
}

public void setMode(HalfFlowMode mode) {
    this.mode = mode;
}

public String getInternalReferent() {
    return internalReferent;
}

public void setInternalReferent(String internalReferent) {
    this.internalReferent = internalReferent;
}

public String getBackupReferent() {
    return backupReferent;
}

public void setBackupReferent(String backupReferent) {
    this.backupReferent = backupReferent;
}

public DataFormat getFormat() {
    return format;
}

public void setFormat(DataFormat format) {
    this.format = format;
}

public Connector getConnector() {
    return connector;
}

public void setConnector(Connector connector) {
    this.connector = connector;
}

public Confidentiality getConfidentiality() {
    return confidentiality;
}

public void setConfidentiality(Confidentiality confidentiality) {
    this.confidentiality = confidentiality;
}

public Integrity getIntegrity() {
    return integrity;
}

public void setIntegrity(Integrity integrity) {
    this.integrity = integrity;
}

public HalfFlowAvailability getHalfFlowAvailability() {
    return halfFlowAvailability;
}

public void setHalfFlowAvailability(HalfFlowAvailability halfFlowAvailability) {
    this.halfFlowAvailability = halfFlowAvailability;
}

public List<HalfFlowApplication> getHalfFlowApplication() {
    return halfFlowApplication;
}

public void setHalfFlowApplication(List<HalfFlowApplication> halfFlowApplication) {
    this.halfFlowApplication = halfFlowApplication;
}

public Exchange getExchange() {
    return exchange;
}

public void setExchange(Exchange exchange) {
    this.exchange = exchange;
}

public Set<ServiceHalfFlow> getServiceHalfFlow() {
    return serviceHalfFlow;
}

public void setServiceHalfFlow(Set<ServiceHalfFlow> serviceHalfFlow) {
    this.serviceHalfFlow = serviceHalfFlow;
}

public List<HalfFlowBu> getHalfFlowBus() {
    if (halfFlowBus != null)
        Collections.sort(halfFlowBus);
    return halfFlowBus;
}

public void setHalfFlowBus(List<HalfFlowBu> halfFlowBus) {
    this.halfFlowBus = halfFlowBus;
}

public boolean isBridge() {
    return bridge;
}

public void setBridge(boolean bridge) {
    this.bridge = bridge;
}

@Override
public String toString() {
    return "HalfFlow{" +
            "id=" + id +
            ", halfFlowNumber='" + halfFlowNumber + '\'' +
            ", name='" + name + '\'' +
            ", way=" + way +
            ", externalDocLink='" + externalDocLink + '\'' +
            ", mode=" + mode +
            ", internalReferent='" + internalReferent + '\'' +
            ", backupReferent='" + backupReferent + '\'' +
            ", format=" + format +
            ", connector=" + connector +
            ", confidentiality=" + confidentiality +
            ", integrity=" + integrity+
            ", halfFlowAvailability=" + halfFlowAvailability +
            ", halfFlowApplication=" + halfFlowApplication +
            ", halfFlowBus=" + halfFlowBus +
            ", serviceHalfFlow=" + serviceHalfFlow +
            (exchange != null ? ", exchange=" + exchange.getName() : "exchange=null" )+
            ", bridge=" + bridge +
            '}';
}
}

这是我的控制器签名：

@RequestMapping(method = RequestMethod.POST)
public ResponseEntity<HalfFlow> save(@RequestBody HalfFlow halfflow){...}

我想知道什么会引发此错误，并且这种出现是随机的。

Answer 1

正如Alex所说，为防止无限递归，您添加了此批注

@JsonIgnoreProperties(value = {"exchange"})
@OneToMany(mappedBy = "exchange")
private List<HalfFlow> halfFlows;

所以我实际上通过在注释中添加以下内容解决了这个问题

@JsonIgnoreProperties(value = {"exchange"}, allowSetters = true)
@OneToMany(mappedBy = "exchange")
private List<HalfFlow> halfFlows;

此解决方案在这里有更好的解释https://softwareengineering.stackexchange.com/questions/300115/best-
way-to-deal-with-hibernate-1-many-relationship-over-rest-json-
service