java spring spring-data couchbase spring-data-couchbase

Spring Data Couchbase custom repository method

Hi all I am having issues adding a simple custom query using the couchbase template on Spring Data Couchbase.

Repository interfaces:

@RepositoryRestResource
public interface EmployeeRepository extends CouchbasePagingAndSortingRepository<Employee, String>, EmployeeCustomRepository {
}

public interface EmployeeCustomRepository {
    List<Employee> customMethod(String firstName, String lastName);
}

Implementation

public class EmployeeRepositoryImpl implements EmployeeCustomRepository, InitializingBean {
    @Autowired
    private RepositoryOperationsMapping templateProvider;
    private CouchbaseOperations template;

    @Override
    public void afterPropertiesSet() throws Exception {
        template = templateProvider.resolve(EmployeeRepository.class, Employee.class);
    }

    @Override
    public List<Employee> customMethod(String firstName, String lastName) {
        N1qlQuery query = N1qlQuery.parameterized(
                "SELECT * FROM " + template.getCouchbaseBucket().name() + " WHERE firstName = $1 AND lastName = $2",
                JsonArray.from(firstName, lastName));
        return template.findByN1QLProjection(query, Employee.class);
    }
}

Model

@Data
@AllArgsConstructor
@Document
public class Employee {
    @Id
    private String id;

    @Field
    private String firstName;

    @Field
    private String lastName;
}

Main application

@SpringBootApplication
public class SpringDataCouchbaseCustomExampleApplication implements CommandLineRunner {

    public static void main(String[] args) {
        SpringApplication.run(SpringDataCouchbaseCustomExampleApplication.class, args);
    }

    @Autowired
    private EmployeeRepository repository;

    @Override
    public void run(String... strings) throws Exception {
        String empId = "1";

        Employee employee = repository.findOne(empId);

        if(employee == null) {
            employee = new Employee(empId, "Joe", "Smith");
            repository.save(employee);
        }

        List<Employee> result = repository.customMethod("Joe", "Smith");

        System.out.println("correct result:" + result.size());


        result = repository.customMethod("Joe", "Wopa");
        System.out.println("no result:" + result.size());
    }
}

Stack trace

java.lang.IllegalStateException: Failed to execute CommandLineRunner
    at org.springframework.boot.SpringApplication.callRunner(SpringApplication.java:803) [spring-boot-1.4.3.RELEASE.jar:1.4.3.RELEASE]
    at org.springframework.boot.SpringApplication.callRunners(SpringApplication.java:784) [spring-boot-1.4.3.RELEASE.jar:1.4.3.RELEASE]
    at org.springframework.boot.SpringApplication.afterRefresh(SpringApplication.java:771) [spring-boot-1.4.3.RELEASE.jar:1.4.3.RELEASE]
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:316) [spring-boot-1.4.3.RELEASE.jar:1.4.3.RELEASE]
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:1186) [spring-boot-1.4.3.RELEASE.jar:1.4.3.RELEASE]
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:1175) [spring-boot-1.4.3.RELEASE.jar:1.4.3.RELEASE]
    at com.example.SpringDataCouchbaseCustomExampleApplication.main(SpringDataCouchbaseCustomExampleApplication.java:14) [classes/:na]
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:1.8.0_77]
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[na:1.8.0_77]
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:1.8.0_77]
    at java.lang.reflect.Method.invoke(Method.java:498) ~[na:1.8.0_77]
    at org.springframework.boot.devtools.restart.RestartLauncher.run(RestartLauncher.java:49) [spring-boot-devtools-1.4.3.RELEASE.jar:1.4.3.RELEASE]
Caused by: java.lang.RuntimeException: Cannot decode ad-hoc JSON
    at org.springframework.data.couchbase.core.convert.translation.JacksonTranslationService.decodeFragment(JacksonTranslationService.java:245) ~[spring-data-couchbase-2.1.6.RELEASE.jar:na]
    at org.springframework.data.couchbase.core.CouchbaseTemplate.findByN1QLProjection(CouchbaseTemplate.java:466) ~[spring-data-couchbase-2.1.6.RELEASE.jar:na]
    at com.example.EmployeeRepositoryImpl.customMethod(EmployeeRepositoryImpl.java:26) ~[classes/:na]
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:1.8.0_77]
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[na:1.8.0_77]
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:1.8.0_77]
    at java.lang.reflect.Method.invoke(Method.java:498) ~[na:1.8.0_77]
    at org.springframework.data.repository.core.support.RepositoryFactorySupport$QueryExecutorMethodInterceptor.executeMethodOn(RepositoryFactorySupport.java:503) ~[spring-data-commons-1.12.6.RELEASE.jar:na]
    at org.springframework.data.repository.core.support.RepositoryFactorySupport$QueryExecutorMethodInterceptor.doInvoke(RepositoryFactorySupport.java:478) ~[spring-data-commons-1.12.6.RELEASE.jar:na]
    at org.springframework.data.repository.core.support.RepositoryFactorySupport$QueryExecutorMethodInterceptor.invoke(RepositoryFactorySupport.java:460) ~[spring-data-commons-1.12.6.RELEASE.jar:na]
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179) ~[spring-aop-4.3.5.RELEASE.jar:4.3.5.RELEASE]
    at org.springframework.data.projection.DefaultMethodInvokingMethodInterceptor.invoke(DefaultMethodInvokingMethodInterceptor.java:61) ~[spring-data-commons-1.12.6.RELEASE.jar:na]
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179) ~[spring-aop-4.3.5.RELEASE.jar:4.3.5.RELEASE]
    at org.springframework.data.couchbase.repository.support.ViewPostProcessor$ViewInterceptor.invoke(ViewPostProcessor.java:87) ~[spring-data-couchbase-2.1.6.RELEASE.jar:na]
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179) ~[spring-aop-4.3.5.RELEASE.jar:4.3.5.RELEASE]
    at org.springframework.aop.interceptor.ExposeInvocationInterceptor.invoke(ExposeInvocationInterceptor.java:92) ~[spring-aop-4.3.5.RELEASE.jar:4.3.5.RELEASE]
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179) ~[spring-aop-4.3.5.RELEASE.jar:4.3.5.RELEASE]
    at org.springframework.aop.interceptor.ExposeInvocationInterceptor.invoke(ExposeInvocationInterceptor.java:92) ~[spring-aop-4.3.5.RELEASE.jar:4.3.5.RELEASE]
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179) ~[spring-aop-4.3.5.RELEASE.jar:4.3.5.RELEASE]
    at org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:213) ~[spring-aop-4.3.5.RELEASE.jar:4.3.5.RELEASE]
    at com.sun.proxy.$Proxy77.customMethod(Unknown Source) ~[na:na]
    at com.example.SpringDataCouchbaseCustomExampleApplication.run(SpringDataCouchbaseCustomExampleApplication.java:31) [classes/:na]
    at org.springframework.boot.SpringApplication.callRunner(SpringApplication.java:800) [spring-boot-1.4.3.RELEASE.jar:1.4.3.RELEASE]
    ... 11 common frames omitted
Caused by: com.fasterxml.jackson.databind.exc.UnrecognizedPropertyException: Unrecognized field "default" (class com.example.Employee), not marked as ignorable (3 known properties: "lastName", "id", "firstName"])
 at [Source: {"default":{"firstName":"Joe","lastName":"Smith","_class":"com.example.Employee"}}; line: 1, column: 83] (through reference chain: com.example.Employee["default"])
    at com.fasterxml.jackson.databind.exc.UnrecognizedPropertyException.from(UnrecognizedPropertyException.java:62) ~[jackson-databind-2.8.5.jar:2.8.5]
    at com.fasterxml.jackson.databind.DeserializationContext.handleUnknownProperty(DeserializationContext.java:834) ~[jackson-databind-2.8.5.jar:2.8.5]
    at com.fasterxml.jackson.databind.deser.std.StdDeserializer.handleUnknownProperty(StdDeserializer.java:1093) ~[jackson-databind-2.8.5.jar:2.8.5]
    at com.fasterxml.jackson.databind.deser.BeanDeserializerBase.handleUnknownProperty(BeanDeserializerBase.java:1477) ~[jackson-databind-2.8.5.jar:2.8.5]
    at com.fasterxml.jackson.databind.deser.BeanDeserializerBase.handleUnknownProperties(BeanDeserializerBase.java:1431) ~[jackson-databind-2.8.5.jar:2.8.5]
    at com.fasterxml.jackson.databind.deser.BeanDeserializer._deserializeUsingPropertyBased(BeanDeserializer.java:487) ~[jackson-databind-2.8.5.jar:2.8.5]
    at com.fasterxml.jackson.databind.deser.BeanDeserializerBase.deserializeFromObjectUsingNonDefault(BeanDeserializerBase.java:1198) ~[jackson-databind-2.8.5.jar:2.8.5]
    at com.fasterxml.jackson.databind.deser.BeanDeserializer.deserializeFromObject(BeanDeserializer.java:314) ~[jackson-databind-2.8.5.jar:2.8.5]
    at com.fasterxml.jackson.databind.deser.BeanDeserializer.deserialize(BeanDeserializer.java:148) ~[jackson-databind-2.8.5.jar:2.8.5]
    at com.fasterxml.jackson.databind.ObjectMapper._readMapAndClose(ObjectMapper.java:3798) ~[jackson-databind-2.8.5.jar:2.8.5]
    at com.fasterxml.jackson.databind.ObjectMapper.readValue(ObjectMapper.java:2842) ~[jackson-databind-2.8.5.jar:2.8.5]
    at org.springframework.data.couchbase.core.convert.translation.JacksonTranslationService.decodeFragment(JacksonTranslationService.java:242) ~[spring-data-couchbase-2.1.6.RELEASE.jar:na]
    ... 33 common frames omitted

Solution

That's due to a mix of how you wrote your query statement and what method you used on the template

On a first note, you are attempting at retrieving Employees, which are fully-fledged entities. This findByN1QLProjection was intended for a different kind of query where you only select a few fields, for instance a count(*) query.

So you should use findByN1ql instead. In any case, there is a problem though: the format returned by N1QL for the simplest (but also most natural) form of queries isn't adapted for Jackson's deserialization.

First, N1QL wraps each result in a JSON object with a single field named after the bucket from which data came, here "default"). This is the issue that you see :(

Second, in order to deserialize an entity, spring-data-couchbase needs your N1QL query to select a couple of specific things that a SELECT(*) doesn't cover: the meta-data (namely the ID and CAS).

We offer the N1qlUtils class to help a bit with that... Note how the section of the doc that deals with writing custom methods is using the N1qlUtils class at step 8 to build the query?

I agree it is a bit misleading as it uses the projection method, so you'd have to adapt it a bit to use N1qlUtils.createSelectFromForEntity and N1qlUtils. createWhereFilterForEntity. Something like this:

// your own WHERE criteria:
Expression where = x("firstName = $1 and lastName = $2");

Statement statement =
    //this will produce the adequate SELECT..FROM.. clause:
    N1qlUtils.createSelectFromForEntity(template.getCouchbaseBucket().name())
    //use the DSL to continue to the WHERE clause
    .where(
        //this will produce the adequate WHERE criterias in addition to your own:
        //(see doc snippet for getting converter and entityInfo)
        N1qlUtils.createWhereFilterForEntity(where, converter, entityInfo));

you can then create a N1qlQuery out of that statement (rather than a String) and execute it using findByN1ql...

quick alternative:

You could use string-based query derivation.

Have a look at this test for an example. You could put a similar signature with a few tweak to the WHERE clause in the annotation in your EmployeeRepository interface (no need for custom implementation there).