[英]Spring-Boot: Failure on running of a spring-boot restful program
[英]Cannot deserialize from String value Spring-Boot Restful project
我正在做一个Spring Boot + Maven + Restful + Hibernate项目! 创建用于在数据库中添加新设备的RestController后,出现此错误:
2018-03-28 10:15:18.786 WARN 9286 --- [nio-9090-exec-9] .w.s.m.s.DefaultHandlerExceptionResolver : Failed to read HTTP message: org.springframework.http.converter.HttpMessageNotReadableException: JSON parse error: Cannot construct instance of `com.hhm.hsy.hibernate.models.Protocol` (although at least one Creator exists): no String-argument constructor/factory method to deserialize from String value ('{"id":5,"protocolName":"ProtocolForTesting","port":5202}'); nested exception is com.fasterxml.jackson.databind.exc.MismatchedInputException: Cannot construct instance of `com.hhm.hsy.hibernate.models.Protocol` (although at least one Creator exists): no String-argument constructor/factory method to deserialize from String value ('{"id":5,"protocolName":"ProtocolForTesting","port":5202}')
at [Source: (PushbackInputStream); line: 1, column: 52] (through reference chain: com.hhm.hsy.hibernate.models.Device["protocol"])
这是我的第一个实体:
@Entity
@Table(name = "devices", catalog = "hqm")
public class Device implements Serializable {
private static final long serialVersionUID = -8311225474375837513L;
@Id
@GeneratedValue(strategy = IDENTITY)
@Column(name = "device_id", unique = true, nullable = false)
private Integer id;
@Column(name = "device_name", unique = true, nullable = false)
private String deviceName;
@ManyToOne
@JoinColumn(name = "protocol_id")
private Protocol protocol;
public Device() {
}
public Device(Integer id, String deviceName, Protocol protocol) {
this.id = id;
this.deviceName = deviceName;
this.protocol = protocol;
}
public Integer getId() {
return id;
}
public void setId(Integer id) {
this.id = id;
}
public String getDeviceName() {
return deviceName;
}
public void setDeviceName(String deviceName) {
this.deviceName = deviceName;
}
public Protocol getProtocol() {
return protocol;
}
public void setProtocol(Protocol protocol) {
this.protocol = protocol;
}
第二个实体:
@Entity
@Table(name = "protocols", catalog = "hqm")
public class Protocol implements Serializable {
@Id
@GeneratedValue(strategy = IDENTITY)
@Column(name = "protocol_id", unique = true, nullable = false)
private Integer id;
@Column(name = "protocol_name", unique = true, nullable = false, length = 45)
private String protocolName;
@Column(name = "port", nullable = false)
private Integer port;
@OneToMany(mappedBy = "protocol", cascade = CascadeType.ALL, orphanRemoval = true)
private Set<Device> devices = new HashSet<>();
public Protocol() {
}
public Protocol(Integer id, String protocolName, Integer port) {
this.id = id;
this.protocolName = protocolName;
this.port = port;
}
public Integer getId() {
return id;
}
public void setId(Integer id) {
this.id = id;
}
public String getProtocolName() {
return protocolName;
}
public void setProtocolName(String protocolName) {
this.protocolName = protocolName;
}
public Integer getPort() {
return port;
}
public void setPort(Integer port) {
this.port = port;
}
@JsonIgnore
public Set<Device> getDevices() {
return devices;
}
@JsonIgnore
public void setDevices(Set<Device> devices) {
this.devices = devices;
}
}
控制器:
@RestController
@RequestMapping(value = "/api/devices")
@ComponentScan({"com.hhm.hsy.pmcs.*"})
public class DevicesController {
@Autowired
@Qualifier(value = "deviceService")
GenericServiceIntf deviceService;
// get ALL DEVICE
@RequestMapping(value = "", method = RequestMethod.GET)
public Map<String, Object> getDevices() {
Map<String, Object> devicesMap = new HashMap<>();
devicesMap.put("devices", deviceService.getAll());
return devicesMap;
}
//save a new DEVICE
@RequestMapping(value = "", method = RequestMethod.POST, consumes = {"application/json"}, produces = {"application/json"})
@ResponseStatus(HttpStatus.CREATED)
public ResponseEntity<Device> addDevice(@RequestBody Device device) {
deviceService.save(device);
return ResponseEntity.accepted().body(device);
}
}
服务:
@Service("deviceService")
public class DeviceServiceImpl extends GenericServiceAbstractImpl<Device, Integer> implements Serializable{
private static final long serialVersionUID = 697655212967127150L;
@Autowired
public DeviceServiceImpl(@Qualifier("deviceDao") GenericDaoIntf genericDao) {
super(genericDao);
}
}
因此,当我尝试添加新设备时,出现上面提到的错误。我不知道是什么导致了此异常。 当我尝试添加新协议以使其工作时,表正在数据库中正确创建,并且我也在GET请求中正确获取数据..请帮助我,我是springboot和restful的新手。如果需要更多信息,请通知我,我将其发布! 谢谢!
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