Spring Boot JacksonTester自定义序列化器未注册

时间：2018-07-06 12:15:42

标签： java spring-boot junit jackson

尝试通过Jackson图书馆进行后续工作。我有以下测试模型：

Address.java 

package com.example.domain;

import java.time.LocalDate;

import org.apache.commons.lang3.builder.EqualsBuilder;
import org.apache.commons.lang3.builder.HashCodeBuilder;
import org.apache.commons.lang3.builder.ToStringBuilder;
import org.apache.commons.lang3.builder.ToStringStyle;

import com.fasterxml.jackson.databind.annotation.JsonDeserialize;
import com.fasterxml.jackson.databind.annotation.JsonSerialize;

public class Address {

    private String addressKey;
    private String postalCode;
    private String country;

    @JsonSerialize(using = DateSerializer.class, as = String.class)
    @JsonDeserialize(using = DateDeserializer.class, as = LocalDate.class)
    private LocalDate dateEntered;

    public String getAddressKey() {
        return addressKey;
    }

    public void setAddressKey(String addressKey) {
        this.addressKey = addressKey;
    }

    public String getPostalCode() {
        return postalCode;
    }

    public void setPostalCode(String postalCode) {
        this.postalCode = postalCode;
    }

    public String getCountry() {
        return country;
    }

    public void setCountry(String country) {
        this.country = country;
    }

    public LocalDate getDateEntered() {
        return dateEntered;
    }

    public void setDateEntered(LocalDate dateEntered) {
        this.dateEntered = dateEntered;
    }

    @Override
    public int hashCode() {
        return HashCodeBuilder.reflectionHashCode(this, false);
    }

    @Override
    public boolean equals(Object obj) {
        return EqualsBuilder.reflectionEquals(this, obj, false);
    }

    @Override
    public String toString() {
        return ToStringBuilder.reflectionToString(this, ToStringStyle.SHORT_PREFIX_STYLE, false);
    }
}

和dateEntered字段的自定义序列化器：

DateSerializer.java 

package com.example.domain;

import java.io.IOException;
import java.time.LocalDate;
import java.time.format.DateTimeFormatter;

import org.springframework.boot.jackson.JsonComponent;

import com.fasterxml.jackson.core.JsonGenerator;
import com.fasterxml.jackson.core.JsonProcessingException;
import com.fasterxml.jackson.databind.JsonSerializer;
import com.fasterxml.jackson.databind.SerializerProvider;

@JsonComponent
public class DateSerializer extends JsonSerializer<LocalDate> {
    @Override
    public void serialize(LocalDate lc, JsonGenerator jsonGenerator, SerializerProvider serializerProvider)
            throws IOException, JsonProcessingException {
        String date = lc.format(DateTimeFormatter.ofPattern("dd MM yyyy"));
        jsonGenerator.writeString(date);
    }
}

我整理了以下测试，利用@JsonTest批注检查序列化程序类是否在执行我认为的应做的事情：

AddressTest.java 

@JsonTest
@RunWith(SpringRunner.class)
public class AddressTest {

@Autowired
private JacksonTester<Address> json;

    @Test
    public void test_Address_serialisation_dateEnteredSerialised() throws Exception {
        final Address address = getTestAddress();

        assertThat(json.write(address))
            .hasJsonPathStringValue("@.dateEntered")
            .extractingJsonPathStringValue("@.dateEntered")
            .isEqualTo("01 05 2018");
    }

    private Address getTestAddress() {
        final Address testAddress = new Address();
        testAddress.setAddressKey("testAddressKey");
        testAddress.setCountry("testCountry");
        testAddress.setPostalCode("testPostalCode");
        testAddress.setDateEntered(LocalDate.of(2018, 5, 1));
        return testAddress;
    }

}

当我运行序列化测试时，我会在控制台中找到它：

com.fasterxml.jackson.databind.JsonMappingException: Invalid definition for property dateEntered (of type 'Lcom/example/domain/Address;'): Can not refine serialization type [simple type, class java.time.LocalDate] into java.lang.String; types not related

at com.fasterxml.jackson.databind.JsonMappingException.from(JsonMappingException.java:284)
at com.fasterxml.jackson.databind.SerializerProvider.mappingException(SerializerProvider.java:1110)
at com.fasterxml.jackson.databind.SerializerProvider.reportBadPropertyDefinition(SerializerProvider.java:1180)
at com.fasterxml.jackson.databind.ser.PropertyBuilder.buildWriter(PropertyBuilder.java:101)
at com.fasterxml.jackson.databind.ser.BeanSerializerFactory._constructWriter(BeanSerializerFactory.java:816)
at com.fasterxml.jackson.databind.ser.BeanSerializerFactory.findBeanProperties(BeanSerializerFactory.java:610)
at com.fasterxml.jackson.databind.ser.BeanSerializerFactory.constructBeanSerializer(BeanSerializerFactory.java:399)
at com.fasterxml.jackson.databind.ser.BeanSerializerFactory.findBeanSerializer(BeanSerializerFactory.java:282)
at com.fasterxml.jackson.databind.ser.BeanSerializerFactory._createSerializer2(BeanSerializerFactory.java:234)
at com.fasterxml.jackson.databind.ser.BeanSerializerFactory.createSerializer(BeanSerializerFactory.java:168)
at com.fasterxml.jackson.databind.SerializerProvider._createUntypedSerializer(SerializerProvider.java:1308)
at com.fasterxml.jackson.databind.SerializerProvider._createAndCacheUntypedSerializer(SerializerProvider.java:1279)
at com.fasterxml.jackson.databind.SerializerProvider.findValueSerializer(SerializerProvider.java:536)
at com.fasterxml.jackson.databind.SerializerProvider.findTypedValueSerializer(SerializerProvider.java:743)
at com.fasterxml.jackson.databind.ser.DefaultSerializerProvider.serializeValue(DefaultSerializerProvider.java:330)
at com.fasterxml.jackson.databind.ObjectWriter$Prefetch.serialize(ObjectWriter.java:1427)
at com.fasterxml.jackson.databind.ObjectWriter._configAndWriteValue(ObjectWriter.java:1158)
at com.fasterxml.jackson.databind.ObjectWriter.writeValueAsString(ObjectWriter.java:1031)
at org.springframework.boot.test.json.JacksonTester.writeObject(JacksonTester.java:116)
at org.springframework.boot.test.json.AbstractJsonMarshalTester.write(AbstractJsonMarshalTester.java:133)
at com.example.domain.AddressTest.test_Address_serialisation_dateEnteredSerialised(AddressTest.java:68)
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.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:252)
at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.runChild(SpringJUnit4ClassRunner.java:94)
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$2.evaluate(ParentRunner.java:268)
at org.springframework.test.context.junit4.statements.RunBeforeTestClassCallbacks.evaluate(RunBeforeTestClassCallbacks.java:61)
at org.springframework.test.context.junit4.statements.RunAfterTestClassCallbacks.evaluate(RunAfterTestClassCallbacks.java:70)
at org.junit.runners.ParentRunner.run(ParentRunner.java:363)
at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.run(SpringJUnit4ClassRunner.java:191)
at org.junit.runner.JUnitCore.run(JUnitCore.java:137)
at com.intellij.junit4.JUnit4IdeaTestRunner.startRunnerWithArgs(JUnit4IdeaTestRunner.java:68)
at com.intellij.rt.execution.junit.IdeaTestRunner$Repeater.startRunnerWithArgs(IdeaTestRunner.java:47)
at com.intellij.rt.execution.junit.JUnitStarter.prepareStreamsAndStart(JUnitStarter.java:242)
at com.intellij.rt.execution.junit.JUnitStarter.main(JUnitStarter.java:70)

据我所知，在与@JsonTest结合使用时，将@JsonComponent添加到类中将允许对其进行拾取和注册，但是基于此看来，似乎并没有对其进行扫描和添加。我是否缺少测试或src代码中的步骤？值得注意的是，反序列化器的设置方式相同（它以特定格式将日期字符串化），并且效果很好。

1 个答案:

答案 0 :(得分：0)

很少需要在as = ...中指定@JsonSerialize，尤其是当您还指定using = ...时。

引自@JsonSerialize.as的javadoc：

  

...
  注意：如果还使用using，则具有优先级   （由于它直接指定了序列化程序，   而这只会用于定位序列化程序）   并且此注释属性的值将被忽略。

在您的情况下：指定as = String.class似乎是罪魁祸首 未找到的JSON序列化程序。

如果您忽略它，请在您的Address类中写

@JsonSerialize(using = DateSerializer.class)
@JsonDeserialize(using = DateDeserializer.class)
private LocalDate dateEntered;

然后找到DateSerializer，AddressTest正常运行。

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