2

I am using Spring data Mongo Db with graph QL and facing an issue while fetching the data from DB for the Abstract class. Please find the below details.

@Data
    public static class Employee<T extends Account> {
        private String name;
        private T account;
    }

    @Data
    public static abstract class Account {
    }

    @Data
    public static class CurrentAccount extends Account {
        private BigDecimal balance;
        private BigDecimal limit;
    }

    @Data
    public static class SavingAccount extends Account {
        private BigDecimal balance;
    }

The generic type is decided at runtime using deserializer as below

private static final JavaType withCurrent = TypeFactory.defaultInstance()
            .constructParametricType(Employee.class, CurrentAccount.class);

    private static final JavaType withSaving = TypeFactory.defaultInstance()
            .constructParametricType(Employee.class, SavingAccount.class);

    public static JavaType determineType(String topic, byte[] data, Headers headers) throws IOException {
        if (headers.lastHeader("accountType").value()[0] == 'C') {
            return withCurrent;
        }
        else {
            return withSaving;
        }
    }

    public static class MySerializer extends JsonSerializer<Employee<?>> {

        @Override
        public byte[] serialize(String topic, Headers headers, Employee<?> emp) {
            headers.add(new RecordHeader("accountType",
                    new byte[] { (byte) (emp.getAccount() instanceof CurrentAccount ? 'C' : 'S')}));
            return super.serialize(topic, headers, emp);
        }

    }

Repository code

@Transactional(readOnly = true)
    @GraphQLQuery
    public EmployeeObjPageable findAllEmployeesBySearchAndSort(SearchSortCriteria ss) {
       
        Optional<EmployeeObjPageable> employees = tradeInstructionRepository.findAllEmployeesBySearchAndSort(ss,
                Employee.class, EmployeeObjPageable.class);
        if (employees.isPresent())
            return getEmployeesDataPageable(employees.get());
    }

public Optional<?> findAllEmployeesBySearchAndSort(SearchSortCriteria ss, Class collectionType, Class outputType) {
        if (ss == null)
            return Optional.of(null);

        TypedAggregation<?> aggregation = Aggregation.newAggregation(collectionType, getAggregationOperation(ss, collectionType, mongoTemplate))
                .withOptions(Aggregation.newAggregationOptions().allowDiskUse(true).build());
        AggregationResults<?> results = mongoTemplate.aggregate(aggregation, collectionType, outputType);
        return Optional.ofNullable(results.getUniqueMappedResult());
    }

So when I try to fetch any data for Employee from Mongo DB then getting the below error

2020-11-25 15:36:36.975 ERROR 9384 --- [io-10010-exec-9] o.a.c.c.C.[.[.[/].[dispatcherServlet]    : 
Servlet.service() for servlet [dispatcherServlet] in context with path [] threw exception
 [Handler dispatch failed; nested exception is java.lang.InstantiationError: com.model.Employee] with root cause

java.lang.InstantiationError: com.model.Account
    at com.model.Account_Instantiator_1wfce5.newInstance(Unknown Source) ~[classes/:na]
    at org.springframework.data.mapping.model.ClassGeneratingEntityInstantiator$EntityInstantiatorAdapter.createInstance(ClassGeneratingEntityInstantiator.java:238) ~[spring-data-commons-2.3.2.RELEASE.jar:2.3.2.RELEASE]
    at org.springframework.data.mapping.model.ClassGeneratingEntityInstantiator.createInstance(ClassGeneratingEntityInstantiator.java:87) ~[spring-data-commons-2.3.2.RELEASE.jar:2.3.2.RELEASE]
    at org.springframework.data.mongodb.core.convert.MappingMongoConverter.read(MappingMongoConverter.java:344) ~[spring-data-mongodb-3.0.2.RELEASE.jar:3.0.2.RELEASE]
    at org.springframework.data.mongodb.core.convert.MappingMongoConverter.read(MappingMongoConverter.java:317) ~[spring-data-mongodb-3.0.2.RELEASE.jar:3.0.2.RELEASE]
    at org.springframework.data.mongodb.core.convert.MappingMongoConverter.readValue(MappingMongoConverter.java:1580) ~[spring-data-mongodb-3.0.2.RELEASE.jar:3.0.2.RELEASE]
    at org.springframework.data.mongodb.core.convert.MappingMongoConverter$MongoDbPropertyValueProvider.getPropertyValue(MappingMongoConverter.java:1478) ~[spring-data-mongodb-3.0.2.RELEASE.jar:3.0.2.RELEASE]
    at org.springframework.data.mongodb.core.convert.MappingMongoConverter.readProperties(MappingMongoConverter.java:450) ~[spring-data-mongodb-3.0.2.RELEASE.jar:3.0.2.RELEASE]
    at org.springframework.data.mongodb.core.convert.MappingMongoConverter.populateProperties(MappingMongoConverter.java:367) ~[spring-data-mongodb-3.0.2.RELEASE.jar:3.0.2.RELEASE]
    at org.springframework.data.mongodb.core.convert.MappingMongoConverter.read(MappingMongoConverter.java:347) ~[spring-data-mongodb-3.0.2.RELEASE.jar:3.0.2.RELEASE]
    at org.springframework.data.mongodb.core.convert.MappingMongoConverter.read(MappingMongoConverter.java:317) ~[spring-data-mongodb-3.0.2.RELEASE.jar:3.0.2.RELEASE]
    at org.springframework.data.mongodb.core.convert.MappingMongoConverter.readCollectionOrArray(MappingMongoConverter.java:1119) ~[spring-data-mongodb-3.0.2.RELEASE.jar:3.0.2.RELEASE]
    at org.springframework.data.mongodb.core.convert.MappingMongoConverter.readValue(MappingMongoConverter.java:1578) ~[spring-data-mongodb-3.0.2.RELEASE.jar:3.0.2.RELEASE]
    at org.springframework.data.mongodb.core.convert.MappingMongoConverter$MongoDbPropertyValueProvider.getPropertyValue(MappingMongoConverter.java:1478) ~[spring-data-mongodb-3.0.2.RELEASE.jar:3.0.2.RELEASE]
    at org.springframework.data.mongodb.core.convert.MappingMongoConverter.readProperties(MappingMongoConverter.java:450) ~[spring-data-mongodb-3.0.2.RELEASE.jar:3.0.2.RELEASE]
    at org.springframework.data.mongodb.core.convert.MappingMongoConverter.populateProperties(MappingMongoConverter.java:367) ~[spring-data-mongodb-3.0.2.RELEASE.jar:3.0.2.RELEASE]
    at org.springframework.data.mongodb.core.convert.MappingMongoConverter.read(MappingMongoConverter.java:347) ~[spring-data-mongodb-3.0.2.RELEASE.jar:3.0.2.RELEASE]
    at org.springframework.data.mongodb.core.convert.MappingMongoConverter.read(MappingMongoConverter.java:317) ~[spring-data-mongodb-3.0.2.RELEASE.jar:3.0.2.RELEASE]
    at org.springframework.data.mongodb.core.convert.MappingMongoConverter.read(MappingMongoConverter.java:250) ~[spring-data-mongodb-3.0.2.RELEASE.jar:3.0.2.RELEASE]
    at org.springframework.data.mongodb.core.convert.MappingMongoConverter.read(MappingMongoConverter.java:246) ~[spring-data-mongodb-3.0.2.RELEASE.jar:3.0.2.RELEASE]
    at org.springframework.data.mongodb.core.convert.MappingMongoConverter.read(MappingMongoConverter.java:98) ~[spring-data-mongodb-3.0.2.RELEASE.jar:3.0.2.RELEASE]
    at org.springframework.data.mongodb.core.MongoTemplate$ReadDocumentCallback.doWith(MongoTemplate.java:3141) ~[spring-data-mongodb-3.0.2.RELEASE.jar:3.0.2.RELEASE]
    at org.springframework.data.mongodb.core.MongoTemplate.lambda$null$23(MongoTemplate.java:2163) ~[spring-data-mongodb-3.0.2.RELEASE.jar:3.0.2.RELEASE]
    at com.mongodb.client.internal.MappingIterable$1.accept(MappingIterable.java:62) ~[mongodb-driver-sync-4.0.5.jar:na]
    at com.mongodb.client.internal.MongoIterableImpl.forEach(MongoIterableImpl.java:123) ~[mongodb-driver-sync-4.0.5.jar:na]
    at com.mongodb.client.internal.MappingIterable.forEach(MappingIterable.java:59) ~[mongodb-driver-sync-4.0.5.jar:na]
    at com.mongodb.client.internal.MappingIterable.into(MappingIterable.java:69) ~[mongodb-driver-sync-4.0.5.jar:na]
    at org.springframework.data.mongodb.core.MongoTemplate.lambda$doAggregate$24(MongoTemplate.java:2166) ~[spring-data-mongodb-3.0.2.RELEASE.jar:3.0.2.RELEASE]
    at org.springframework.data.mongodb.core.MongoTemplate.execute(MongoTemplate.java:566) ~[spring-data-mongodb-3.0.2.RELEASE.jar:3.0.2.RELEASE]
    at org.springframework.data.mongodb.core.MongoTemplate.doAggregate(MongoTemplate.java:2124) ~[spring-data-mongodb-3.0.2.RELEASE.jar:3.0.2.RELEASE]
    at org.springframework.data.mongodb.core.MongoTemplate.aggregate(MongoTemplate.java:2093) ~[spring-data-mongodb-3.0.2.RELEASE.jar:3.0.2.RELEASE]
    at org.springframework.data.mongodb.core.MongoTemplate.aggregate(MongoTemplate.java:1983) ~[spring-data-mongodb-3.0.2.RELEASE.jar:3.0.2.RELEASE]
    at com.empolyee.util.SearchAndSortUtil.getAggregateDocuments(FGPSSUtil.java:36) ~[classes/:na]
    at com.empolyee.repository.CustomAggregationImpl.findAllEmployeesBySearchAndSort(CustomAggregationImpl.java:20) ~[classes/:na]
    at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:na]
    at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[na:na]
    at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:na]
    at java.base/java.lang.reflect.Method.invoke(Method.java:566) ~[na:na]
    at org.springframework.data.repository.core.support.ImplementationInvocationMetadata.invoke(ImplementationInvocationMetadata.java:72) ~[spring-data-commons-2.3.2.RELEASE.jar:2.3.2.RELEASE]
    at org.springframework.data.repository.core.support.RepositoryComposition$RepositoryFragments.invoke(RepositoryComposition.java:382) ~[spring-data-commons-2.3.2.RELEASE.jar:2.3.2.RELEASE]
    at org.springframework.data.repository.core.support.RepositoryComposition.invoke(RepositoryComposition.java:205) ~[spring-data-commons-2.3.2.RELEASE.jar:2.3.2.RELEASE]
    at org.springframework.data.repository.core.support.RepositoryFactorySupport$ImplementationMethodExecutionInterceptor.invoke(RepositoryFactorySupport.java:549) ~[spring-data-commons-2.3.2.RELEASE.jar:2.3.2.RELEASE]
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:186) ~[spring-aop-5.2.8.RELEASE.jar:5.2.8.RELEASE]
    at org.springframework.data.repository.core.support.QueryExecutorMethodInterceptor.doInvoke(QueryExecutorMethodInterceptor.java:155) ~[spring-data-commons-2.3.2.RELEASE.jar:2.3.2.RELEASE]
    at org.springframework.data.repository.core.support.QueryExecutorMethodInterceptor.invoke(QueryExecutorMethodInterceptor.java:130) ~[spring-data-commons-2.3.2.RELEASE.jar:2.3.2.RELEASE]
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:186) ~[spring-aop-5.2.8.RELEASE.jar:5.2.8.RELEASE]
    at org.springframework.data.projection.DefaultMethodInvokingMethodInterceptor.invoke(DefaultMethodInvokingMethodInterceptor.java:80) ~[spring-data-commons-2.3.2.RELEASE.jar:2.3.2.RELEASE]
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:186) ~[spring-aop-5.2.8.RELEASE.jar:5.2.8.RELEASE]
    at org.springframework.aop.interceptor.ExposeInvocationInterceptor.invoke(ExposeInvocationInterceptor.java:95) ~[spring-aop-5.2.8.RELEASE.jar:5.2.8.RELEASE]
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:186) ~[spring-aop-5.2.8.RELEASE.jar:5.2.8.RELEASE]
    at org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:212) ~[spring-aop-5.2.8.RELEASE.jar:5.2.8.RELEASE]
    at com.sun.proxy.$Proxy104.findAllEmployeesBySearchAndSort(Unknown Source) ~[na:na]
    at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:na]
    at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[na:na]
    at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:na]
    at java.base/java.lang.reflect.Method.invoke(Method.java:566) ~[na:na]
    at org.springframework.aop.support.AopUtils.invokeJoinpointUsingReflection(AopUtils.java:344) ~[spring-aop-5.2.8.RELEASE.jar:5.2.8.RELEASE]
    at org.springframework.aop.framework.ReflectiveMethodInvocation.invokeJoinpoint(ReflectiveMethodInvocation.java:198) ~[spring-aop-5.2.8.RELEASE.jar:5.2.8.RELEASE]
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:163) ~[spring-aop-5.2.8.RELEASE.jar:5.2.8.RELEASE]
    at org.springframework.dao.support.PersistenceExceptionTranslationInterceptor.invoke(PersistenceExceptionTranslationInterceptor.java:139) ~[spring-tx-5.2.8.RELEASE.jar:5.2.8.RELEASE]
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:186) ~[spring-aop-5.2.8.RELEASE.jar:5.2.8.RELEASE]
    at org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:212) ~[spring-aop-5.2.8.RELEASE.jar:5.2.8.RELEASE]
    at com.sun.proxy.$Proxy104.findAllEmployeesBySearchAndSort(Unknown Source) ~[na:na]
    at com.service.EmployeeService.findAllEmployeesBySearchAndSort(EmployeeService.java:229) ~[classes/:na]
    at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:na]
    at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[na:na]
    at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:na]
    at java.base/java.lang.reflect.Method.invoke(Method.java:566) ~[na:na]
    at io.leangen.graphql.metadata.execution.SingletonMethodInvoker.execute(SingletonMethodInvoker.java:21) ~[spqr-0.9.9.jar:na]
    at io.leangen.graphql.metadata.Resolver.resolve(Resolver.java:100) ~[spqr-0.9.9.jar:na]
    at io.leangen.graphql.execution.OperationExecutor.lambda$execute$1(OperationExecutor.java:93) ~[spqr-0.9.9.jar:na]
    at io.leangen.graphql.execution.OperationExecutor.execute(OperationExecutor.java:98) ~[spqr-0.9.9.jar:na]
    at io.leangen.graphql.execution.OperationExecutor.execute(OperationExecutor.java:94) ~[spqr-0.9.9.jar:na]
    at io.leangen.graphql.execution.OperationExecutor.execute(OperationExecutor.java:59) ~[spqr-0.9.9.jar:na]
    at graphql.execution.ExecutionStrategy.fetchField(ExecutionStrategy.java:261) ~[graphql-java-11.0.jar:na]
    at graphql.execution.ExecutionStrategy.resolveFieldWithInfo(ExecutionStrategy.java:202) ~[graphql-java-11.0.jar:na]
    at graphql.execution.AsyncExecutionStrategy.execute(AsyncExecutionStrategy.java:70) ~[graphql-java-11.0.jar:na]
    at graphql.execution.Execution.executeOperation(Execution.java:159) ~[graphql-java-11.0.jar:na]
    at graphql.execution.Execution.execute(Execution.java:101) ~[graphql-java-11.0.jar:na]
    at graphql.GraphQL.execute(GraphQL.java:573) ~[graphql-java-11.0.jar:na]
    at graphql.GraphQL.parseValidateAndExecute(GraphQL.java:515) ~[graphql-java-11.0.jar:na]
    at graphql.GraphQL.executeAsync(GraphQL.java:489) ~[graphql-java-11.0.jar:na]
    at graphql.GraphQL.execute(GraphQL.java:420) ~[graphql-java-11.0.jar:na]
    at io.leangen.graphql.spqr.spring.web.servlet.DefaultGraphQLExecutor.execute(DefaultGraphQLExecutor.java:23) ~[graphql-spqr-spring-boot-autoconfigure-0.0.4.jar:na]
    at io.leangen.graphql.spqr.spring.web.servlet.DefaultGraphQLExecutor.execute(DefaultGraphQLExecutor.java:11) ~[graphql-spqr-spring-boot-autoconfigure-0.0.4.jar:na]
    at io.leangen.graphql.spqr.spring.web.GraphQLController.executeJsonPost(GraphQLController.java:42) ~[graphql-spqr-spring-boot-autoconfigure-0.0.4.jar:na]
    at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:na]
    at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[na:na]
    at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:na]
    at java.base/java.lang.reflect.Method.invoke(Method.java:566) ~[na:na]
    at org.springframework.web.method.support.InvocableHandlerMethod.doInvoke(InvocableHandlerMethod.java:190) ~[spring-web-5.2.8.RELEASE.jar:5.2.8.RELEASE]
    at org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:138) ~[spring-web-5.2.8.RELEASE.jar:5.2.8.RELEASE]
    at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:105) ~[spring-webmvc-5.2.8.RELEASE.jar:5.2.8.RELEASE]
    at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:878) ~[spring-webmvc-5.2.8.RELEASE.jar:5.2.8.RELEASE]
    at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:792) ~[spring-webmvc-5.2.8.RELEASE.jar:5.2.8.RELEASE]
    at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:87) ~[spring-webmvc-5.2.8.RELEASE.jar:5.2.8.RELEASE]
    at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:1040) ~[spring-webmvc-5.2.8.RELEASE.jar:5.2.8.RELEASE]
    at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:943) ~[spring-webmvc-5.2.8.RELEASE.jar:5.2.8.RELEASE]
    at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:1006) ~[spring-webmvc-5.2.8.RELEASE.jar:5.2.8.RELEASE]
    at org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:909) ~[spring-webmvc-5.2.8.RELEASE.jar:5.2.8.RELEASE]
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:652) ~[tomcat-embed-core-9.0.37.jar:4.0.FR]
    at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:883) ~[spring-webmvc-5.2.8.RELEASE.jar:5.2.8.RELEASE]
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:733) ~[tomcat-embed-core-9.0.37.jar:4.0.FR]
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:231) ~[tomcat-embed-core-9.0.37.jar:9.0.37]
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-9.0.37.jar:9.0.37]
    at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:53) ~[tomcat-embed-websocket-9.0.37.jar:9.0.37]
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-9.0.37.jar:9.0.37]
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-9.0.37.jar:9.0.37]
    at org.springframework.web.filter.RequestContextFilter.doFilterInternal(RequestContextFilter.java:100) ~[spring-web-5.2.8.RELEASE.jar:5.2.8.RELEASE]
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119) ~[spring-web-5.2.8.RELEASE.jar:5.2.8.RELEASE]
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-9.0.37.jar:9.0.37]
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-9.0.37.jar:9.0.37]
    at org.springframework.web.filter.FormContentFilter.doFilterInternal(FormContentFilter.java:93) ~[spring-web-5.2.8.RELEASE.jar:5.2.8.RELEASE]
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119) ~[spring-web-5.2.8.RELEASE.jar:5.2.8.RELEASE]
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-9.0.37.jar:9.0.37]
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-9.0.37.jar:9.0.37]
    at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:201) ~[spring-web-5.2.8.RELEASE.jar:5.2.8.RELEASE]
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119) ~[spring-web-5.2.8.RELEASE.jar:5.2.8.RELEASE]
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-9.0.37.jar:9.0.37]
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-9.0.37.jar:9.0.37]
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:202) ~[tomcat-embed-core-9.0.37.jar:9.0.37]
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:96) ~[tomcat-embed-core-9.0.37.jar:9.0.37]
    at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:541) ~[tomcat-embed-core-9.0.37.jar:9.0.37]
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:139) ~[tomcat-embed-core-9.0.37.jar:9.0.37]
    at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:92) ~[tomcat-embed-core-9.0.37.jar:9.0.37]
    at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:74) ~[tomcat-embed-core-9.0.37.jar:9.0.37]
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:343) ~[tomcat-embed-core-9.0.37.jar:9.0.37]
    at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:373) ~[tomcat-embed-core-9.0.37.jar:9.0.37]
    at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:65) ~[tomcat-embed-core-9.0.37.jar:9.0.37]
    at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:868) ~[tomcat-embed-core-9.0.37.jar:9.0.37]
    at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1589) ~[tomcat-embed-core-9.0.37.jar:9.0.37]
    at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49) ~[tomcat-embed-core-9.0.37.jar:9.0.37]
    at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1128) ~[na:na]
    at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:628) ~[na:na]
    at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61) ~[tomcat-embed-core-9.0.37.jar:9.0.37]
    at java.base/java.lang.Thread.run(Thread.java:834) ~[na:na]

MongoDb not able to instantiate the Abstract classes. I tried below but no luck https://medium.com/@mladen.maravic/spring-data-mongodb-my-take-on-inheritance-support-102361c08e3d

Spring Data Rest Repository with abstract class / inheritance

Please suggest something

Ganesh
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1 Answers1

1

The issue got resolved by removing all the data from the Employee collection. The reason is collection was holding the mixed data

  1. Data inserted by Java program in below format.
{
 "Employee": {
    "name": "ABC",
    "account": {
        "balance":"1000",
         "limit":"10000",
         "_class":"com.model.CurrentAccount"
        }
   }
}
  1. Manually inserted data, in below format.
{
 "Employee": {
    "name": "ABC",
    "account": {
        "balance":"1000",
         "limit":"10000"
        }
   }
}

As manually inserted data dont have _class field, the mongo db was not able to map the abstract account type object to its concrete class and was throwing exception "java.lang.InstantiationError: com.model.Account". Hence after removing all the data or manual entries from the Employee collection, the java program started fetching the data from the Mongo collection.

Ganesh
  • 903
  • 1
  • 8
  • 18