Spring JpaRepository Hibernate Jackson Junit Test, Controller.

Error:

org.hibernate.LazyInitializationException: failed to lazily initialize a collection of role: xx.xx.xx.db.xx.xx.xx.xx, could not initialize proxy - no Session at org.hibernate.collection.internal.AbstractPersistentCollection.throwLazyInitializationException(AbstractPersistentCollection.java:588) [hibernate-core-5.3.3.Final.jar:5.3.3.Final] at org.hibernate.collection.internal.AbstractPersistentCollection.withTemporarySessionIfNeeded(AbstractPersistentCollection.java:207) [hibernate-core-5.3.3.Final.jar:5.3.3.Final] at org.hibernate.collection.internal.AbstractPersistentCollection.readSize(AbstractPersistentCollection.java:151) [hibernate-core-5.3.3.Final.jar:5.3.3.Final] at org.hibernate.collection.internal.PersistentBag.size(PersistentBag.java:261) [hibernate-core-5.3.3.Final.jar:5.3.3.Final] at com.fasterxml.jackson.databind.ser.std.CollectionSerializer.serialize(CollectionSerializer.java:97) [jackson-databind-2.9.5.jar:2.9.5] at com.fasterxml.jackson.databind.ser.std.CollectionSerializer.serialize(CollectionSerializer.java:25) [jackson-databind-2.9.5.jar:2.9.5] at com.fasterxml.jackson.databind.ser.BeanPropertyWriter.serializeAsField(BeanPropertyWriter.java:727) [jackson-databind-2.9.5.jar:2.9.5] at com.fasterxml.jackson.databind.ser.std.BeanSerializerBase.serializeFields(BeanSerializerBase.java:719) [jackson-databind-2.9.5.jar:2.9.5] at com.fasterxml.jackson.databind.ser.BeanSerializer.serialize(BeanSerializer.java:155) [jackson-databind-2.9.5.jar:2.9.5] at com.fasterxml.jackson.databind.ser.BeanPropertyWriter.serializeAsField(BeanPropertyWriter.java:727) [jackson-databind-2.9.5.jar:2.9.5] at com.fasterxml.jackson.databind.ser.std.BeanSerializerBase.serializeFields(BeanSerializerBase.java:719) [jackson-databind-2.9.5.jar:2.9.5] at com.fasterxml.jackson.databind.ser.BeanSerializer.serialize(BeanSerializer.java:155) [jackson-databind-2.9.5.jar:2.9.5] at com.fasterxml.jackson.databind.ser.DefaultSerializerProvider._serialize(DefaultSerializerProvider.java:480) [jackson-databind-2.9.5.jar:2.9.5] at com.fasterxml.jackson.databind.ser.DefaultSerializerProvider.serializeValue(DefaultSerializerProvider.java:319) [jackson-databind-2.9.5.jar:2.9.5] at com.fasterxml.jackson.databind.ObjectMapper._configAndWriteValue(ObjectMapper.java:3893) [jackson-databind-2.9.5.jar:2.9.5] at com.fasterxml.jackson.databind.ObjectMapper.writeValueAsString(ObjectMapper.java:3207) [jackson-databind-2.9.5.jar:2.9.5]

Config to clear error:


Reference URL:
https://coderleaf.wordpress.com/2016/11/07/jackson-serialization-and-hibernate-lazy-loading/

@Configurationpublic class WebMvcConfig extends WebMvcConfigurationSupport{     @Override    protected void extendMessageConverters( List<HttpMessageConverter<?>> converters ) {        for ( HttpMessageConverter<?> converter : converters ) {            if ( converter instanceof MappingJackson2HttpMessageConverter ) {                MappingJackson2HttpMessageConverter jacksonConverter = (MappingJackson2HttpMessageConverter) converter;                                ObjectMapper objectMapper = jacksonConverter.getObjectMapper();                                 //--- register hibernateModule in MappingJackson2HttpMessageConverter.objectMapper                objectMapper.registerModule(new Hibernate4Module());                 //--- other configurations                jacksonConverter.setPrettyPrint( true );                objectMapper.disable(SerializationFeature.WRITE_DATES_AS_TIMESTAMPS);                                objectMapper.enable(SerializationFeature.INDENT_OUTPUT);            }        }                 super.configureMessageConverters(converters);    } }

xml config to clear error

Reference URL:
https://stackoverflow.com/questions/43946323/spring-and-mappingjackson2httpmessageconverter-and-registermodule

<mvc:annotation-driven>
    <mvc:message-converters register-defaults="true">
        <bean
            class="org.springframework.http.converter.json.MappingJackson2HttpMessageConverter">
            <property name="objectMapper" ref="objectMapper" />
        </bean>
    </mvc:message-converters>
</mvc:annotation-driven>

<bean id="objectMapper"
    class="org.springframework.http.converter.json.Jackson2ObjectMapperFactoryBean">

    <property name="featuresToDisable">
        <array>
            <util:constant
                static-field="com.fasterxml.jackson.databind.SerializationFeature.WRITE_DATES_AS_TIMESTAMPS" />
        </array>
    </property>

    <property name="dateFormat">
        <bean class="java.text.SimpleDateFormat">
            <constructor-arg type="java.lang.String" value="yyyy-MM-dd"></constructor-arg>
        </bean>
    </property>

    <property name="modulesToInstall"
        value="
        com.fasterxml.jackson.datatype.jdk8.Jdk8Module,
    com.fasterxml.jackson.datatype.jsr310.JavaTimeModule,
    com.fasterxml.jackson.module.paramnames.ParameterNamesModule" />
</bean>