无法从START_ARRAY中反序列化“com.dto.Consumption”的实例

Question

我在下面有这个查询，它返回对象“消耗”列表。我在JSON反序列化期间收到错误，请参阅下面的第二种方法。

 @Query("select new com.dto.Consumption(DATE(date), "
                 + "sum(consume), "
                 + "avg(consume), "
                 + "min(consume), "
                 + "max(consume)) "
        + "from HorlyConsumption "
        + "where plate.id = :plateId "
        + "and DATE(date) >= :date "
        + "group by DATE(date) "
        )
        List<Consumption> findAllDailyConsumptionByPlatelId(@Param("plateId") Long plateId, @Param("date") Date date);


@GetMapping(path = "/api/plates/{plateId}/daily")
    public ResponseEntity<?> allDailyConsumption(
            @PathVariable(value = "plateId") String plateId) {

        return ResponseEntity.ok(dailyConsumptionService
                .getAllDailyConsumptionByPlateId(plateId, LocalDate.now()));
    }

public class Consumption implements Serializable {

    /**
     * 
     */
    private static final long serialVersionUID = 1L;

    private Date date;

    private Long sum;

    private Double average;

    private Long min;

    private Long max;

    public Consumption() {

    }

    public Consumption(Date date, Long sum, Double average, Long min, Long max) {
        this.date = date;
        this.sum = sum;
        this.average = average;
        this.min = min;
        this.max = max;
    }

... gets and sets

}

这是例外

org.springframework.web.client.RestClientException: Error while extracting response for type [class com.dto.Consumption] and content type [application/json;charset=UTF-8]; nested exception is org.springframework.http.converter.HttpMessageNotReadableException: JSON parse error: Cannot deserialize instance of `com.dto.Consumption` out of START_ARRAY token; nested exception is com.fasterxml.jackson.databind.exc.MismatchedInputException: Cannot deserialize instance of `com.dto.Consumption` out of START_ARRAY token
    at [Source: (PushbackInputStream); line: 1, column: 1]
    at org.springframework.web.client.HttpMessageConverterExtractor.extractData(HttpMessageConverterExtractor.java:115)
    at org.springframework.web.client.RestTemplate$ResponseEntityResponseExtractor.extractData(RestTemplate.java:991)
    at org.springframework.web.client.RestTemplate$ResponseEntityResponseExtractor.extractData(RestTemplate.java:974)
    at org.springframework.web.client.RestTemplate.doExecute(RestTemplate.java:725)
    at org.springframework.web.client.RestTemplate.execute(RestTemplate.java:680)
    at org.springframework.web.client.RestTemplate.getForEntity(RestTemplate.java:359)
    at org.springframework.boot.test.web.client.TestRestTemplate.getForEntity(TestRestTemplate.java:271)
    at com.controller.PlateControllerTest.testAllDailyConsumptionWithAValidPlate(PanelControllerTest.java:91)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:498)
    at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:50)
    at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12)
    at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:47)
    at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:17)
    at org.springframework.test.context.junit4.statements.RunBeforeTestExecutionCallbacks.evaluate(RunBeforeTestExecutionCallbacks.java:73)
    at org.springframework.test.context.junit4.statements.RunAfterTestExecutionCallbacks.evaluate(RunAfterTestExecutionCallbacks.java:83)
    at org.junit.internal.runners.statements.RunBefores.evaluate(RunBefores.java:26)
    at org.springframework.test.context.junit4.statements.RunBeforeTestMethodCallbacks.evaluate(RunBeforeTestMethodCallbacks.java:75)
    at org.springframework.test.context.junit4.statements.RunAfterTestMethodCallbacks.evaluate(RunAfterTestMethodCallbacks.java:86)
    at org.springframework.test.context.junit4.statements.SpringRepeat.evaluate(SpringRepeat.java:84)
    at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:325)
    at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.runChild(SpringJUnit4ClassRunner.java:251)
    at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.runChild(SpringJUnit4ClassRunner.java:97)
    at org.junit.runners.ParentRunner$3.run(ParentRunner.java:290)
    at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:71)
    at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:288)
    at org.junit.runners.ParentRunner.access$000(ParentRunner.java:58)
    at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:268)
    at org.springframework.test.context.junit4.statements.RunBeforeTestClassCallbacks.evaluate(RunBeforeTestClassCallbacks.java:61)
    at org.springframework.test.context.junit4.statements.RunAfterTestClassCallbacks.evaluate(RunAfterTestClassCallbacks.java:70)
    at org.junit.runners.ParentRunner.run(ParentRunner.java:363)
    at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.run(SpringJUnit4ClassRunner.java:190)
    at org.eclipse.jdt.internal.junit4.runner.JUnit4TestReference.run(JUnit4TestReference.java:86)
    at org.eclipse.jdt.internal.junit.runner.TestExecution.run(TestExecution.java:38)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:538)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:760)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:460)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:206)
Caused by: org.springframework.http.converter.HttpMessageNotReadableException: JSON parse error: Cannot deserialize instance of `com.dto.Consumption` out of START_ARRAY token; nested exception is com.fasterxml.jackson.databind.exc.MismatchedInputException: Cannot deserialize instance of `com.dto.Consumption` out of START_ARRAY token
 at [Source: (PushbackInputStream); line: 1, column: 1]
    at org.springframework.http.converter.json.AbstractJackson2HttpMessageConverter.readJavaType(AbstractJackson2HttpMessageConverter.java:241)
    at org.springframework.http.converter.json.AbstractJackson2HttpMessageConverter.read(AbstractJackson2HttpMessageConverter.java:223)
    at org.springframework.web.client.HttpMessageConverterExtractor.extractData(HttpMessageConverterExtractor.java:100)
    ... 39 more
Caused by: com.fasterxml.jackson.databind.exc.MismatchedInputException: Cannot deserialize instance of `com.dto.Consumption` out of START_ARRAY token
 at [Source: (PushbackInputStream); line: 1, column: 1]
    at com.fasterxml.jackson.databind.exc.MismatchedInputException.from(MismatchedInputException.java:63)
    at com.fasterxml.jackson.databind.DeserializationContext.reportInputMismatch(DeserializationContext.java:1342)
    at com.fasterxml.jackson.databind.DeserializationContext.handleUnexpectedToken(DeserializationContext.java:1138)
    at com.fasterxml.jackson.databind.DeserializationContext.handleUnexpectedToken(DeserializationContext.java:1092)
    at com.fasterxml.jackson.databind.deser.BeanDeserializerBase.deserializeFromArray(BeanDeserializerBase.java:1454)
    at com.fasterxml.jackson.databind.deser.BeanDeserializer._deserializeOther(BeanDeserializer.java:185)
    at com.fasterxml.jackson.databind.deser.BeanDeserializer.deserialize(BeanDeserializer.java:161)
    at com.fasterxml.jackson.databind.ObjectMapper._readMapAndClose(ObjectMapper.java:4001)
    at com.fasterxml.jackson.databind.ObjectMapper.readValue(ObjectMapper.java:3072)
    at org.springframework.http.converter.json.AbstractJackson2HttpMessageConverter.readJavaType(AbstractJackson2HttpMessageConverter.java:235)
    ... 41 more

请问，有什么帮助吗？

Answer 1

返回集合：

@GetMapping(path = "/api/plates/{plateId}/daily")
public ResponseEntity<List<Consumption>> allDailyConsumption(
    @PathVariable(value = "plateId") String plateId) {
    return ResponseEntity
            .ok(dailyConsumptionService.getAllDailyConsumptionByPlateId(plateId,
                                                                        LocalDate.now()));
}