Spring Data AWS DynamoDB Repository Find By Contains throws ClassCastException

Question

I have an AWS DynamoDB Table called Group Table. It contains two fields ID and Members. The members field is a String Set. I would like to search the Group Table and return all Groups where the list of members contains a specified string.

When I attempt this using Spring Data's CRUD Repository FindByMembersContains, it returns a ClassCastException stating java.lang.String cannot be cast to java.util.Collection.

I have also attempted with a String List instead of String Set and get the same results.

I am using AWS Java SDK DynamoDB version 1.12.192 and Spring Data DynamoDB version 5.1.0. I have no issues writing these entries or reading by ID using the repository.

Group.java

@DynamoDBTable(tableName = "GroupTable")
public class Group {

    String id;
    Set members;

    @DynamoDBHashKey
    @DynamoDBAutoGeneratedKey
    public String getId() {
        return id;
    }

    public void setId(String id) {
        this.id = id;
    }

    @DynamoDBAttribute
    public Set getMembers() {
        return members;
    }

    public void setMembers(Set members) {
        this.members = members;
    }

}

GroupRepository.java

@EnableScan
public interface GroupRepository extends CrudRepository {

    List findByMembersContaining(String member);

}

GroupController.java

@RestController
@RequestMapping("/group")
public class GroupController {

    private final GroupRepository groupRepository;

    public GroupController(GroupRepository groupRepository) {
        this.groupRepository = groupRepository;
    }

    @GetMapping("/test")
    public List getTestGroups() {
        String testMemberId = "SomeMemberId";
        return groupRepository.findByMembersContaining(testMemberId);
    }

}

DynamoDBConfig.java

@Configuration
@EnableDynamoDBRepositories(basePackages = "com.example.dynamodbtest.repository")
public class DynamoDBConfig {

    @Value("${amazon.dynamodb.endpoint}")
    private String amazonDynamoDBEndpoint;

    @Value("${amazon.aws.accesskey}")
    private String amazonAWSAccessKey;

    @Value("${amazon.aws.secretkey}")
    private String amazonAWSSecretKey;

    private final ApplicationContext context;

    public DynamoDBConfig(ApplicationContext context) {
        this.context = context;
    }

    @Bean
    public AmazonDynamoDB amazonDynamoDB() {
        AmazonDynamoDB amazonDynamoDB = new AmazonDynamoDBClient(amazonAWSCredentials());
        if (!ObjectUtils.isEmpty(amazonDynamoDBEndpoint)) {
            amazonDynamoDB.setEndpoint(amazonDynamoDBEndpoint);
        }
        return amazonDynamoDB;
    }

    @Bean
    public AWSCredentials amazonAWSCredentials() {
        return new BasicAWSCredentials(amazonAWSAccessKey, amazonAWSSecretKey);
    }

    @Bean(name = "mvcHandlerMappingIntrospectorCustom")
    public HandlerMappingIntrospector mvcHandlerMappingIntrospectorCustom() {
        HandlerMappingIntrospector handlerMappingIntrospector = new HandlerMappingIntrospector();
        handlerMappingIntrospector.setApplicationContext(context);
        return handlerMappingIntrospector;
    }

}

Stack Trace

java.lang.ClassCastException: java.lang.String cannot be cast to java.util.Collection
    at com.amazonaws.services.dynamodbv2.datamodeling.StandardTypeConverters$Vector$ToSet$1.convert(StandardTypeConverters.java:449) ~[aws-java-sdk-dynamodb-1.12.192.jar:na]
    at com.amazonaws.services.dynamodbv2.datamodeling.DynamoDBTypeConverter$DelegateConverter.convert(DynamoDBTypeConverter.java:104) ~[aws-java-sdk-dynamodb-1.12.192.jar:na]
    at com.amazonaws.services.dynamodbv2.datamodeling.DynamoDBTypeConverter$NullSafeConverter.convert(DynamoDBTypeConverter.java:123) ~[aws-java-sdk-dynamodb-1.12.192.jar:na]
    at com.amazonaws.services.dynamodbv2.datamodeling.DynamoDBTypeConverter$ExtendedConverter.convert(DynamoDBTypeConverter.java:83) ~[aws-java-sdk-dynamodb-1.12.192.jar:na]
    at com.amazonaws.services.dynamodbv2.datamodeling.DynamoDBMapperFieldModel.convert(DynamoDBMapperFieldModel.java:138) ~[aws-java-sdk-dynamodb-1.12.192.jar:na]
    at org.socialsignin.spring.data.dynamodb.repository.query.AbstractDynamoDBQueryCriteria.getPropertyAttributeValue(AbstractDynamoDBQueryCriteria.java:499) ~[spring-data-dynamodb-5.1.0.jar:5.1.0]
    at org.socialsignin.spring.data.dynamodb.repository.query.AbstractDynamoDBQueryCriteria.createSingleValueCondition(AbstractDynamoDBQueryCriteria.java:648) ~[spring-data-dynamodb-5.1.0.jar:5.1.0]
    at org.socialsignin.spring.data.dynamodb.repository.query.AbstractDynamoDBQueryCriteria.withSingleValueCriteria(AbstractDynamoDBQueryCriteria.java:427) ~[spring-data-dynamodb-5.1.0.jar:5.1.0]
    at org.socialsignin.spring.data.dynamodb.repository.query.AbstractDynamoDBQueryCreator.addCriteria(AbstractDynamoDBQueryCreator.java:103) ~[spring-data-dynamodb-5.1.0.jar:5.1.0]
    at org.socialsignin.spring.data.dynamodb.repository.query.AbstractDynamoDBQueryCreator.create(AbstractDynamoDBQueryCreator.java:74) ~[spring-data-dynamodb-5.1.0.jar:5.1.0]
    at org.socialsignin.spring.data.dynamodb.repository.query.AbstractDynamoDBQueryCreator.create(AbstractDynamoDBQueryCreator.java:42) ~[spring-data-dynamodb-5.1.0.jar:5.1.0]
    at org.springframework.data.repository.query.parser.AbstractQueryCreator.createCriteria(AbstractQueryCreator.java:119) ~[spring-data-commons-2.6.3.jar:2.6.3]
    at org.springframework.data.repository.query.parser.AbstractQueryCreator.createQuery(AbstractQueryCreator.java:95) ~[spring-data-commons-2.6.3.jar:2.6.3]
    at org.springframework.data.repository.query.parser.AbstractQueryCreator.createQuery(AbstractQueryCreator.java:81) ~[spring-data-commons-2.6.3.jar:2.6.3]
    at org.socialsignin.spring.data.dynamodb.repository.query.PartTreeDynamoDBQuery.doCreateQuery(PartTreeDynamoDBQuery.java:56) ~[spring-data-dynamodb-5.1.0.jar:5.1.0]
    at org.socialsignin.spring.data.dynamodb.repository.query.AbstractDynamoDBQuery.doCreateQueryWithPermissions(AbstractDynamoDBQuery.java:81) ~[spring-data-dynamodb-5.1.0.jar:5.1.0]
    at org.socialsignin.spring.data.dynamodb.repository.query.AbstractDynamoDBQuery$CollectionExecution.execute(AbstractDynamoDBQuery.java:100) ~[spring-data-dynamodb-5.1.0.jar:5.1.0]
    at org.socialsignin.spring.data.dynamodb.repository.query.AbstractDynamoDBQuery.execute(AbstractDynamoDBQuery.java:311) ~[spring-data-dynamodb-5.1.0.jar:5.1.0]
    at org.springframework.data.repository.core.support.RepositoryMethodInvoker.doInvoke(RepositoryMethodInvoker.java:137) ~[spring-data-commons-2.6.3.jar:2.6.3]
    at org.springframework.data.repository.core.support.RepositoryMethodInvoker.invoke(RepositoryMethodInvoker.java:121) ~[spring-data-commons-2.6.3.jar:2.6.3]
    at org.springframework.data.repository.core.support.QueryExecutorMethodInterceptor.doInvoke(QueryExecutorMethodInterceptor.java:159) ~[spring-data-commons-2.6.3.jar:2.6.3]
    at org.springframework.data.repository.core.support.QueryExecutorMethodInterceptor.invoke(QueryExecutorMethodInterceptor.java:138) ~[spring-data-commons-2.6.3.jar:2.6.3]
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:186) ~[spring-aop-5.3.18.jar:5.3.18]
    at org.springframework.aop.interceptor.ExposeInvocationInterceptor.invoke(ExposeInvocationInterceptor.java:97) ~[spring-aop-5.3.18.jar:5.3.18]
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:186) ~[spring-aop-5.3.18.jar:5.3.18]
    at org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:215) ~[spring-aop-5.3.18.jar:5.3.18]
    at com.sun.proxy.$Proxy69.findByMembersContaining(Unknown Source) ~[na:na]
    at com.example.dynamodbtest.controller.GroupController.getTestGroups(GroupController.java:24) ~[classes/:na]
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:1.8.0_191]
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[na:1.8.0_191]
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:1.8.0_191]
    at java.lang.reflect.Method.invoke(Method.java:498) ~[na:1.8.0_191]
    at org.springframework.web.method.support.InvocableHandlerMethod.doInvoke(InvocableHandlerMethod.java:205) ~[spring-web-5.3.18.jar:5.3.18]
    at org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:150) ~[spring-web-5.3.18.jar:5.3.18]
    at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:117) ~[spring-webmvc-5.3.18.jar:5.3.18]
    at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:895) ~[spring-webmvc-5.3.18.jar:5.3.18]
    at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:808) ~[spring-webmvc-5.3.18.jar:5.3.18]
    at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:87) ~[spring-webmvc-5.3.18.jar:5.3.18]
    at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:1067) ~[spring-webmvc-5.3.18.jar:5.3.18]
    at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:963) ~[spring-webmvc-5.3.18.jar:5.3.18]
    at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:1006) ~[spring-webmvc-5.3.18.jar:5.3.18]
    at org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:898) ~[spring-webmvc-5.3.18.jar:5.3.18]
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:655) ~[tomcat-embed-core-9.0.60.jar:4.0.FR]
    at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:883) ~[spring-webmvc-5.3.18.jar:5.3.18]
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:764) ~[tomcat-embed-core-9.0.60.jar:4.0.FR]
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:227) ~[tomcat-embed-core-9.0.60.jar:9.0.60]
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:162) ~[tomcat-embed-core-9.0.60.jar:9.0.60]
    at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:53) ~[tomcat-embed-websocket-9.0.60.jar:9.0.60]
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:189) ~[tomcat-embed-core-9.0.60.jar:9.0.60]
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:162) ~[tomcat-embed-core-9.0.60.jar:9.0.60]
    at org.springframework.web.filter.RequestContextFilter.doFilterInternal(RequestContextFilter.java:100) ~[spring-web-5.3.18.jar:5.3.18]
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:117) ~[spring-web-5.3.18.jar:5.3.18]
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:189) ~[tomcat-embed-core-9.0.60.jar:9.0.60]
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:162) ~[tomcat-embed-core-9.0.60.jar:9.0.60]
    at org.springframework.web.filter.FormContentFilter.doFilterInternal(FormContentFilter.java:93) ~[spring-web-5.3.18.jar:5.3.18]
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:117) ~[spring-web-5.3.18.jar:5.3.18]
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:189) ~[tomcat-embed-core-9.0.60.jar:9.0.60]
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:162) ~[tomcat-embed-core-9.0.60.jar:9.0.60]
    at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:201) ~[spring-web-5.3.18.jar:5.3.18]
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:117) ~[spring-web-5.3.18.jar:5.3.18]
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:189) ~[tomcat-embed-core-9.0.60.jar:9.0.60]
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:162) ~[tomcat-embed-core-9.0.60.jar:9.0.60]
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:197) ~[tomcat-embed-core-9.0.60.jar:9.0.60]
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:97) [tomcat-embed-core-9.0.60.jar:9.0.60]
    at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:541) [tomcat-embed-core-9.0.60.jar:9.0.60]
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:135) [tomcat-embed-core-9.0.60.jar:9.0.60]
    at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:92) [tomcat-embed-core-9.0.60.jar:9.0.60]
    at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:78) [tomcat-embed-core-9.0.60.jar:9.0.60]
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:360) [tomcat-embed-core-9.0.60.jar:9.0.60]
    at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:399) [tomcat-embed-core-9.0.60.jar:9.0.60]
    at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:65) [tomcat-embed-core-9.0.60.jar:9.0.60]
    at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:889) [tomcat-embed-core-9.0.60.jar:9.0.60]
    at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1743) [tomcat-embed-core-9.0.60.jar:9.0.60]
    at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49) [tomcat-embed-core-9.0.60.jar:9.0.60]
    at org.apache.tomcat.util.threads.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1191) [tomcat-embed-core-9.0.60.jar:9.0.60]
    at org.apache.tomcat.util.threads.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:659) [tomcat-embed-core-9.0.60.jar:9.0.60]
    at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61) [tomcat-embed-core-9.0.60.jar:9.0.60]
    at java.lang.Thread.run(Thread.java:748) [na:1.8.0_191]

AWS DynamoDB Object Group Object Showing String Set

user_6707212 · Answer

Swapping to Enhanced Client, I was able to perform a 'Scan' with a 'Filter Expression' to return the results I want.

private DynamoDbClient getClient() {
    Region region = Region.US_EAST_2;
    return DynamoDbClient.builder()
            .region(region)
            .build();
}

private DynamoDbEnhancedClient getEnhancedClient() {
    return DynamoDbEnhancedClient.builder()
            .dynamoDbClient(getClient())
            .build();
}

public List scanGroupsByMember(String memberId) {

    DynamoDbTable groupTable = getEnhancedClient().table("GroupTable", TableSchema.fromClass(Group.class));

    AttributeValue attributeValue = AttributeValue.builder()
            .s(memberId)
            .build();

    Map expressionValues = new HashMap<>();
    expressionValues.put(":value", attributeValue);

    Expression expression = Expression.builder()
            .expression("contains(members, :value)")
            .expressionValues(expressionValues)
            .build();

    ScanEnhancedRequest scanEnhancedRequest = ScanEnhancedRequest.builder()
            .filterExpression(expression)
            .build();

    return groupTable.scan(scanEnhancedRequest).items().stream().collect(Collectors.toList());

}

user_1435543 · Answer

"I am using AWS Java SDK DynamoDB version 1.12.192".

You should use AWS SDK for Java V2 and to map Java classes to a DynamoDB table by using the Enhanced Client. This is best practice as opposed to using the old V1 API. See this doc topic:

Using the DynamoDB Enhanced Client in the AWS SDK for Java 2.x

Assume we have a Work table with a key named id. The following illustration shows the table.

TO map to this table, you can create a class that uses the @DynamoDbBean annotation like this:

 import software.amazon.awssdk.enhanced.dynamodb.mapper.annotations.DynamoDbSortKey;
import software.amazon.awssdk.enhanced.dynamodb.mapper.annotations.DynamoDbBean;
import software.amazon.awssdk.enhanced.dynamodb.mapper.annotations.DynamoDbPartitionKey;
        
            @DynamoDbBean
             public class Work {
        
               private String id;
               private String date;
               private String description ;
               private String guide;
               private String username ;
               private String status  ;
               private String archive   ;
        
               @DynamoDbPartitionKey
               public String getId() {
                 return this.id;
               }
        
               public void setId(String id) {
                this.id = id;
               }
        
               @DynamoDbSortKey
               public String getName() {
                return this.username;
                }
        
               public void setArchive(String archive) {
                this.archive = archive;
                }
        
               public String getArchive() {
                 return this.archive;
                }
        
               public void setStatus(String status) {
                 this.status = status;
               }
        
               public String getStatus() {
                return this.status;
               }
        
              public void setUsername(String username) {
               this.username = username;
              }
        
              public String getUsername() {
               return this.username;
              }
        
              public void setGuide(String guide) {
                this.guide = guide;
            }
        
              public String getGuide() {
                return this.guide;
              }
        
              public String getDate() {
               return this.date;
               }
        
              public void setDate(String date) {
               this.date = date;
              }
        
              public String getDescription() {
               return description;
              }
        
             public void setDescription(String description) {
              this.description = description;
               }
              }

To use the Enhanced Client to perform CRUD operation, create a DynamoDbTable object.

// Create a DynamoDbEnhancedClient.
 DynamoDbEnhancedClient enhancedClient = DynamoDbEnhancedClient.builder()
                .dynamoDbClient(getClient())
                .build();

 // Create a DynamoDbTable object.
 DynamoDbTable workTable = enhancedClient.table("Work", TableSchema.fromBean(Work.class));

Now you can perform CRUD operations. To place a record into the table, you can create a Work object and set the data. Then call the DynamoDbTable objects putItem method.

// Populate the table.
 Work record = new Work();
 record.setUsername(item.getName());
 record.setId(myGuid);
 record.setDescription(item.getDescription());
 record.setDate(now()) ;
 record.setStatus(item.getStatus());
 record.setArchive("Open");
 record.setGuide(item.getGuide());

 // Put the customer data into a DynamoDB table.
  workTable.putItem(record);

The Amazon DynamoDB API V2 (Including the Enhanced Client) can be used within a Spring BOOT app too. To learn How TO build a SAMPLE Spring Boot web App, see this AWS tutorial.

Spring Data AWS DynamoDB Repository Find By Contains throws ClassCastException

2 Answers