N1qlUtils

N1qlUtils

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java - Spring Data Couchbase自定义存储库方法

大家好，我在使用Spring Data Couchbase上的couchbase模板添加简单的自定义查询时遇到问题。

仓库接口：

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

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


实作

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);
    }
}


模型

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

    @Field
    private String firstName;

    @Field
    private String lastName;
}


主要用途

@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());
    }
}


堆栈跟踪

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

最佳答案

这是由于您混合编写了查询语句以及在模板上使用了哪种方法

首先，您正在尝试检索Employee，它们是成熟的实体。此findByN1QLProjection用于另一种查询，在该查询中您仅选择一些字段，例如count(*)查询。

因此，您应该改用findByN1ql。无论如何，都存在一个问题：N1QL针对最简单（也是最自然）的查询形式返回的格式不适用于Jackson的反序列化。

首先，N1QL将每个结果包装在一个JSON对象中，该对象具有一个以数据存储桶命名的字段，此处为“默认”。这是您看到的问题：(

其次，为了反序列化实体，spring-data-couchbase需要您的N1QL查询来选择SELECT(*)不能涵盖的一些特定内容：元数据（即ID和CAS） 。

我们提供N1qlUtils类来帮助您解决这个问题。
注意用于编写自定义方法的section of the doc在第8步如何使用N1qlUtils类来构建查询？

我同意使用投影方法会有点误导，因此您必须对其稍加调整才能使用N1qlUtils.createSelectFromForEntity和N1qlUtils. createWhereFilterForEntity。像这样：

// 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));


然后可以从该语句（而不是字符串）中创建一个N1qlQuery并使用findByN1ql执行它。

快速替代：

您可以使用基于字符串的查询派生。

以this test为例。您可以对EmployeeRepository接口中的批注中的WHERE子句进行一些调整，以放置类似的签名（无需在那里进行自定义实现）。

08-06 12:49
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