我正在使用r2dbc
,r2dbc-h2
和实验性的spring-boot-starter-data-r2dbc
我正在使用 r2dbc
、r2dbc-h2
和实验性的 spring-boot-starter-data-r2dbc
implementation 'org.springframework.boot.experimental:spring-boot-starter-data-r2dbc:0.1.0.M1'
implementation 'org.springframework.data:spring-data-r2dbc:1.0.0.RELEASE' // starter-data provides old version
implementation 'io.r2dbc:r2dbc-h2:0.8.0.RELEASE'
implementation 'io.r2dbc:r2dbc-pool:0.8.0.RELEASE'
我已经创建了响应式仓库。
public interface IJsonComparisonRepository extends ReactiveCrudRepository<JsonComparisonResult, String> {}
还添加了一个自定义脚本,在启动时创建一个H2中的表
@SpringBootApplication
public class JsonComparisonApplication {
public static void main(String[] args) {
SpringApplication.run(JsonComparisonApplication.class, args);
}
@Bean
public CommandLineRunner startup(DatabaseClient client) {
return (args) -> client
.execute(() -> {
var resource = new ClassPathResource("ddl/script.sql");
try (var is = new InputStreamReader(resource.getInputStream())) {
return FileCopyUtils.copyToString(is);
} catch (IOException e) {
throw new RuntimeException(e);
} })
.then()
.block();
}
}
我的 r2dbc
配置看起来像这样
@Configuration
@EnableR2dbcRepositories
public class R2dbcConfiguration extends AbstractR2dbcConfiguration {
@Override
public ConnectionFactory connectionFactory() {
return new H2ConnectionFactory(
H2ConnectionConfiguration.builder()
.url("mem:testdb;DB_CLOSE_DELAY=-1;DB_CLOSE_ON_EXIT=FALSE")
.username("sa")
.build());
}
}
我执行逻辑的服务看起来像这样
@Override
public Mono<JsonComparisonResult> updateOrCreateRightSide(String comparisonId, String json) {
return updateComparisonSide(comparisonId, storedComparisonResult -> {
storedComparisonResult.setRightSide(json);
return storedComparisonResult;
});
}
private Mono<JsonComparisonResult> updateComparisonSide(String comparisonId,
Function<JsonComparisonResult, JsonComparisonResult> updateSide) {
return repository.findById(comparisonId)
.defaultIfEmpty(createResult(comparisonId))
.filter(result -> ComparisonDecision.NONE == result.getDecision()) // if not NONE - it means it was found and completed
.switchIfEmpty(Mono.error(new NotUpdatableCompleteComparisonException(comparisonId)))
.map(updateSide)
.flatMap(repository::save);
}
private JsonComparisonResult createResult(String comparisonId) {
LOGGER.info("Creating new comparison result: {}.", comparisonId);
var newResult = new JsonComparisonResult();
newResult.setDecision(ComparisonDecision.NONE);
newResult.setComparisonId(comparisonId);
return newResult;
}
这个域名看起来像是这样的
@Table("json_comparison")
public class JsonComparisonResult {
@Column("comparison_id")
@Id
private String comparisonId;
@Column("left")
private String leftSide;
@Column("right")
private String rightSide;
// @Enumerated(EnumType.STRING) - no support for now
@Column("decision")
private ComparisonDecision decision;
private String differences;
问题在于,当我尝试将任何对象添加到数据库时,都会出现异常。
org.springframework.dao.TransientDataAccessResourceException: Failed to update table [json_comparison]. Row with Id [4] does not exist.
at org.springframework.data.r2dbc.repository.support.SimpleR2dbcRepository.lambda$save$0(SimpleR2dbcRepository.java:91) ~[spring-data-r2dbc-1.0.0.RELEASE.jar:1.0.0.RELEASE]
at reactor.core.publisher.FluxHandle$HandleSubscriber.onNext(FluxHandle.java:96) ~[reactor-core-3.3.1.RELEASE.jar:3.3.1.RELEASE]
at reactor.core.publisher.FluxOnErrorResume$ResumeSubscriber.onNext(FluxOnErrorResume.java:73) ~[reactor-core-3.3.1.RELEASE.jar:3.3.1.RELEASE]
at reactor.core.publisher.MonoUsingWhen$MonoUsingWhenSubscriber.deferredComplete(MonoUsingWhen.java:276) ~[reactor-core-3.3.1.RELEASE.jar:3.3.1.RELEASE]
at reactor.core.publisher.FluxUsingWhen$CommitInner.onComplete(FluxUsingWhen.java:536) ~[reactor-core-3.3.1.RELEASE.jar:3.3.1.RELEASE]
at reactor.core.publisher.Operators$MultiSubscriptionSubscriber.onComplete(Operators.java:1858) ~[reactor-core-3.3.1.RELEASE.jar:3.3.1.RELEASE]
at reactor.core.publisher.Operators.complete(Operators.java:132) ~[reactor-core-3.3.1.RELEASE.jar:3.3.1.RELEASE]
at reactor.core.publisher.MonoEmpty.subscribe(MonoEmpty.java:45) ~[reactor-core-3.3.1.RELEASE.jar:3.3.1.RELEASE]
at reactor.core.publisher.MonoDefer.subscribe(MonoDefer.java:52) ~[reactor-core-3.3.1.RELEASE.jar:3.3.1.RELEASE]
由于某种原因,在SimpleR2dbcRepository
库类中的save
过程中,它不将objectToSave
视为新对象,但实际上它并不存在,所以更新失败。
// SimpleR2dbcRepository#save
@Override
@Transactional
public <S extends T> Mono<S> save(S objectToSave) {
Assert.notNull(objectToSave, "Object to save must not be null!");
if (this.entity.isNew(objectToSave)) { // not new
....
}
}
为什么会发生这种情况,问题出在哪里?
@Id
,我就不必手动提供它或其他什么吗?因为在转换为响应式之前,一切都正常。 - lapots@Id
只是其中一种选择。您还可以通过提供自己的isNew()
实现来实现Persistable
接口。 - mp911despring-data-jpa
使用了一些自定义版本的persistable
或entityInformation
? - lapotsisNew()
提示中恢复过来的。JPA 有所谓的附加实体的概念,帮助 JPA 确定一个实体是否为新的。如果 JPA 无法确定一个实体是否为新的,它会在INSERT
/UPDATE
之前发出SELECT
来与数据库状态同步。 - mp911depersistable
接口,而不是为域实现persistable
? - lapots