java Spring Boot：没有从字符串值反序列化的字符串参数构造函数/工厂方法
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Spring Boot: no String-argument constructor/factory method to deserialize from String value
提问by dbeja
I'm trying to read a response from a rest service with RestTemplate (Spring Boot):
我正在尝试使用 RestTemplate (Spring Boot) 读取来自休息服务的响应：
RestTemplate restTemplate = new RestTemplate();
ResponseEntity<RMSendPropertyResponse> response = restTemplate.exchange("https://url", HttpMethod.POST, entity, RMSendPropertyResponse.class);
RMSendPropertyResponse rmResponse = response.getBody();
But when errors array is present on the response:
但是当响应中存在错误数组时：
{
"message": "Something failed.",
"success": false,
"errors": [
{
"error_code": "MND_00026",
"error_value": "",
"error_description": "field not present"
},
{
"error_code": "VAL_00039",
"error_value": "0",
"error_description": "Wrong field"
}
],
"warnings": null,
"request_timestamp": "18-07-2017 11:34:46",
"response_timestamp": "18-07-2017 11:34:46"
}
I always get this error:
我总是收到这个错误：
2017-07-18 12:29:08.220 WARN 9489 --- [nio-8080-exec-9] .w.s.m.s.DefaultHandlerExceptionResolver : Failed to read HTTP message: org.springframework.http.converter.HttpMessageNotReadableException: Could not read document: Can not construct instance of co.easymatch.portals.rightmove.entities.RMError: no String-argument constructor/factory method to deserialize from String value ('MND_00026') at [Source: java.io.PushbackInputStream@77f5bb5f; line: 1, column: 532] (through reference chain: co.portals.entities.RMSendPropertyResponse["errors"]->java.util.ArrayList[0]); nested exception is com.fasterxml.Hymanson.databind.JsonMappingException: Can not construct instance of co.portals.entities.RMError: no String-argument constructor/factory method to deserialize from String value ('MND_00026') at [Source: java.io.PushbackInputStream@77f5bb5f; line: 1, column: 532] (through reference chain: co.portals.entities.RMSendPropertyResponse["errors"]->java.util.ArrayList[0])
2017-07-18 12:29:08.220 WARN 9489 --- [nio-8080-exec-9] .wsmsDefaultHandlerExceptionResolver：无法读取 HTTP 消息：org.springframework.http.converter.HttpMessageNotReadableException：无法读取文档：无法构造 co.easymatch.portals.rightmove.entities.RMError 的实例：在 [来源：java.io.PushbackInputStream@77f5bb5f; 没有从字符串值 ('MND_00026') 反序列化的字符串参数构造函数/工厂方法；行：1，列：532]（通过参考链：co.portals.entities.RMSendPropertyResponse["errors"]->java.util.ArrayList[0]）；嵌套异常是 com.fasterxml.Hymanson.databind.JsonMappingException：无法构造 co.portals.entities.RMError 的实例：没有从字符串值反序列化的字符串参数构造函数/工厂方法（'MND_00026' ) 在 [来源：java.io.PushbackInputStream@77f5bb5f; 行：1，列：532]（通过参考链：co.portals.entities.RMSendPropertyResponse["errors"]->java.util.ArrayList[0]）
And my classes are...
而我的课...
RMSendPropertyResponse class:
RMSendPropertyResponse 类：
@JsonIgnoreProperties(ignoreUnknown = true)
public class RMSendPropertyResponse extends RMResponse {
private RMPropertyResponse property;
private List<RMWarning> warnings;
private List<RMError> errors;
public RMSendPropertyResponse() {
}
public RMPropertyResponse getProperty() {
return property;
}
public void setProperty(RMPropertyResponse property) {
this.property = property;
}
public List<RMWarning> getWarnings() {
return warnings;
}
public void setWarnings(List<RMWarning> warnings) {
this.warnings = warnings;
}
public List<RMError> getErrors() {
return errors;
}
public void setErrors(List<RMError> errors) {
this.errors = errors;
}
}
RMError class:
RMError 类：
@JsonIgnoreProperties(ignoreUnknown = true)
public class RMError {
private String error_code;
private String error_description;
private String error_value;
public RMError() {
}
public String getError_code() {
return error_code;
}
public void setError_code(String error_code) {
this.error_code = error_code;
}
public String getError_description() {
return error_description;
}
public void setError_description(String error_description) {
this.error_description = error_description;
}
public String getError_value() {
return error_value;
}
public void setError_value(String error_value) {
this.error_value = error_value;
}
}
I can't understand why there isn't a constructor/factory method to deserialize from String value.
我不明白为什么没有从 String 值反序列化的构造函数/工厂方法。
Thanks
谢谢
采纳答案by Akli REGUIG
Your code works for me.
What is the version of spring-bootyour are using? do you manage yourself Hymanson's version ? if so what version is it your are using.
Are you sure that the response you get from the external url you are calling is what you pasted in the question ?
Here is the working code i copied :
你的代码对我有用。你用的是什么版本spring-boot？你管理自己Hymanson的版本吗？如果是这样，您使用的是什么版本。您确定从您正在调用的外部 url 获得的响应是您粘贴在问题中的内容吗？这是我复制的工作代码：
@RestController
public class MyController {
@GetMapping(value = "/read", produces = MediaType.APPLICATION_JSON_VALUE)
public ResponseEntity read() {
RestTemplate restTemplate = new RestTemplate();
ResponseEntity<RMSendPropertyResponse> response = restTemplate.exchange("http://localhost:8080/", HttpMethod.GET, null, RMSendPropertyResponse.class);
RMSendPropertyResponse rmResponse = response.getBody();
return new ResponseEntity<>(rmResponse, HttpStatus.CREATED);
}
@GetMapping(value = "/", produces = MediaType.APPLICATION_JSON_VALUE)
public String get() {
return "{\n" +
" \"message\": \"Something failed.\",\n" +
" \"success\": false,\n" +
" \"errors\": [\n" +
" {\n" +
" \"error_code\": \"MND_00026\",\n" +
" \"error_value\": \"\",\n" +
" \"error_description\": \"field not present\"\n" +
" },\n" +
" {\n" +
" \"error_code\": \"VAL_00039\",\n" +
" \"error_value\": \"0\",\n" +
" \"error_description\": \"Wrong field\"\n" +
" }\n" +
" ],\n" +
" \"warnings\": null,\n" +
" \"request_timestamp\": \"18-07-2017 11:34:46\",\n" +
" \"response_timestamp\": \"18-07-2017 11:34:46\"\n" +
"}";
}
}
@JsonIgnoreProperties(ignoreUnknown = true)
class RMError {
private String error_code;
private String error_description;
private String error_value;
public RMError() {
}
public String getError_code() {
return error_code;
}
public void setError_code(String error_code) {
this.error_code = error_code;
}
public String getError_description() {
return error_description;
}
public void setError_description(String error_description) {
this.error_description = error_description;
}
public String getError_value() {
return error_value;
}
public void setError_value(String error_value) {
this.error_value = error_value;
}
}
@JsonIgnoreProperties(ignoreUnknown = true)
class RMSendPropertyResponse {
private List<RMError> errors;
public RMSendPropertyResponse() {
}
public List<RMError> getErrors() {
return errors;
}
public void setErrors(List<RMError> errors) {
this.errors = errors;
}
}
