Question

在lagom项目中，我尝试使用 Accessors 但是我得到一个错误。

java.util.concurrent.CompletionException：java.lang.RuntimeException：为访问器TestAccessor准备查询时出错在java.util.concurrent.CompletableFuture.encodeThrowable（CompletableFuture.java:273）在java.util.concurrent.CompletableFuture.uniComposeStage（CompletableFuture.java:991）在java.util.concurrent.CompletableFuture.thenCompose（CompletableFuture.java:2124）在java.util.concurrent.CompletableFuture.thenCompose（CompletableFuture.java:110）在org.test.impl.persist.CassandraRepository.getAll（CassandraRepository.java:98）在org.test.impl.workers.Worker.lambda $ testMessage $ 2（Worker.java:91）在java.util.concurrent.CompletableFuture.uniCompose（CompletableFuture.java:952）在java.util.concurrent.CompletableFuture $ UniCompose.tryFire（CompletableFuture.java:926）在java.util.concurrent.CompletableFuture.postComplete（CompletableFuture.java:474）在java.util.concurrent.CompletableFuture.complete（CompletableFuture.java:1962）在com.spotify.futures.ListenableToCompletableFutureWrapper.onSuccess（ListenableToCompletableFutureWrapper.java:49）在com.google.common.util.concurrent.Futures $ CallbackListener.run（Futures.java:1237） com.google.common.util.concurrent.MoreExecutors $ DirectExecutor.execute（MoreExecutors.java:399）在com.google.common.util.concurrent.AbstractFuture.executeListener（AbstractFuture.java:911）在com.google.common.util.concurrent.AbstractFuture.complete（AbstractFuture.java:822）在com.google.common.util.concurrent.AbstractFuture.set（AbstractFuture.java:664）在com.google.common.util.concurrent.AbstractTransformFuture $ TransformFuture.setResult（AbstractTransformFuture.java:245）在com.google.common.util.concurrent.AbstractTransformFuture.run（AbstractTransformFuture.java:177） com.google.common.util.concurrent.MoreExecutors $ DirectExecutor.execute（MoreExecutors.java:399）在com.google.common.util.concurrent.AbstractFuture.executeListener（AbstractFuture.java:911）在com.google.common.util.concurrent.AbstractFuture.complete（AbstractFuture.java:822）在com.google.common.util.concurrent.AbstractFuture.set（AbstractFuture.java:664）在com.datastax.driver.core.DefaultResultSetFuture.onSet（DefaultResultSetFuture.java:174）在com.datastax.driver.core.RequestHandler.setFinalResult（RequestHandler.java:198） at com.datastax.driver.core.RequestHandler.access $ 2600（RequestHandler.java:50）在com.datastax.driver.core.RequestHandler $ SpeculativeExecution.setFinalResult（RequestHandler.java:852）在com.datastax.driver.core.RequestHandler $ SpeculativeExecution.onSet（RequestHandler.java:556）在com.datastax.driver.core.Connection $ Dispatcher.channelRead0（Connection.java:1087）在com.datastax.driver.core.Connection $ Dispatcher.channelRead0（Connection.java:1010）在io.netty.channel.SimpleChannelInboundHandler.channelRead（SimpleChannelInboundHandler.java:105）在io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead（AbstractChannelHandlerContext.java:362）在io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead（AbstractChannelHandlerContext.java:348）在io.netty.channel.AbstractChannelHandlerContext.fireChannelRead（AbstractChannelHandlerContext.java:340）在io.netty.handler.timeout.IdleStateHandler.channelRead（IdleStateHandler.java:286）在io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead（AbstractChannelHandlerContext.java:362）在io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead（AbstractChannelHandlerContext.java:348）在io.netty.channel.AbstractChannelHandlerContext.fireChannelRead（AbstractChannelHandlerContext.java:340）在io.netty.handler.codec.MessageToMessageDecoder.channelRead（MessageToMessageDecoder.java:102）在io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead（AbstractChannelHandlerContext.java:362）在io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead（AbstractChannelHandlerContext.java:348）在io.netty.channel.AbstractChannelHandlerContext.fireChannelRead（AbstractChannelHandlerContext.java:340）在io.netty.handler.codec.ByteToMessageDecoder.fireChannelRead（ByteToMessageDecoder.java:310）在io.netty.handler.codec.ByteToMessageDecoder.channelRead（ByteToMessageDecoder.java:284）在io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead（AbstractChannelHandlerContext.java:362）在io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead（AbstractChannelHandlerContext.java:348）在io.netty.channel.AbstractChannelHandlerContext.fireChannelRead（AbstractChannelHandlerContext.java:340）在io.netty.channel.ChannelInboundHandlerAdapter.channelRead（ChannelInboundHandlerAdapter.java:86）在com.datastax.driver.core.InboundTrafficMeter.channelRead（InboundTrafficMeter.java:38）在io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead（AbstractChannelHandlerContext.java:362）在io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead（AbstractChannelHandlerContext.java:348）在io.netty.channel.AbstractChannelHandlerContext.fireChannelRead（AbstractChannelHandlerContext.java:340）在io.netty.channel.DefaultChannelPipeline $ HeadContext.channelRead（DefaultChannelPipeline.java:1434）在io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead（AbstractChannelHandlerContext.java:362）在io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead（AbstractChannelHandlerContext.java:348）在io.netty.channel.DefaultChannelPipeline.fireChannelRead（DefaultChannelPipeline.java:965）在io.netty.channel.nio.AbstractNioByteChannel $ NioByteUnsafe.read（AbstractNioByteChannel.java:163）在io.netty.channel.nio.NioEventLoop.processSelectedKey（NioEventLoop.java:647）在io.netty.channel.nio.NioEventLoop.processSelectedKeysOptimized（NioEventLoop.java:582）在io.netty.channel.nio.NioEventLoop.processSelectedKeys（NioEventLoop.java:499）在io.netty.channel.nio.NioEventLoop.run（NioEventLoop.java:461）在io.netty.util.concurrent.SingleThreadEventExecutor $ 5.run（SingleThreadEventExecutor.java:884）在io.netty.util.concurrent.FastThreadLocalRunnable.run（FastThreadLocalRunnable.java:30）在java.lang.Thread.run（Thread.java:748）由以下原因引起：java.lang.RuntimeException：为访问器TestAccessor准备查询时出错在com.datastax.driver.mapping.AccessorMapper.prepare（AccessorMapper.java:61）在com.datastax.driver.mapping.MappingManager.getAccessor（MappingManager.java:335）在com.datastax.driver.mapping.MappingManager.createAccessor（MappingManager.java:297）在org.test.impl.persist.CassandraRepository.lambda $ getAll $ 5（CassandraRepository.java:99）在java.util.concurrent.CompletableFuture.uniComposeStage（CompletableFuture.java:981） ...省略了61个通用框架原因：java.util.concurrent.ExecutionException：com.datastax.driver.core.exceptions.OperationTimedOutException：[localhost / 127.0.0.1：9042]超时，等待服务器响应在com.google.common.util.concurrent.AbstractFuture.getDoneValue（AbstractFuture.java:503）在com.google.common.util.concurrent.AbstractFuture.get（AbstractFuture.java:482）在com.google.common.util.concurrent.AbstractFuture $ TrustedFuture.get（AbstractFuture.java:79）在com.datastax.driver.mapping.AccessorMapper.prepare（AccessorMapper.java:57） ...省略了65个通用框架引起原因：com.datastax.driver.core.exceptions.OperationTimedOutException：[localhost / 127.0.0.1：9042]等待服务器响应时超时在com.datastax.driver.core.RequestHandler $ SpeculativeExecution.onTimeout（RequestHandler.java:825）在com.datastax.driver.core.Connection $ ResponseHandler $ 1.run（Connection.java:1392）在io.netty.util.HashedWheelTimer $ HashedWheelTimeout.expire（HashedWheelTimer.java:668）在io.netty.util.HashedWheelTimer $ HashedWheelBucket.expireTimeouts（HashedWheelTimer.java:743）在io.netty.util.HashedWheelTimer $ Worker.run（HashedWheelTimer.java:471） ...省略了2个共同的框架

访问者

@Accessor
public interface TestAccessor {
    @Query("SELECT * FROM test_table")
    Result<TestTable> getAll();
}

用法

TestAccessor acc = mappingManager.createAccessor(TestAccessor.class);
Result<TestTable> channels = acc.getAll();

提供会话和映射器。

public class Module extends AbstractModule implements ServiceGuiceSupport, AkkaGuiceSupport {
    private static CompletableFuture<Void> codecRegistrationPromise = new CompletableFuture<>();

    @Override
    protected void configure() {
        bindService(TestService.class, TestServiceImpl.class);
    }

    @Provides
    @Singleton
    public CompletionStage<MappingManager> provideMappingManager(CompletionStage<Session> session) {
        return session.thenApply(MappingManager::new));
    }

    @Provides
    public CompletionStage<Cluster> provideCassandraCluster(CompletionStage<Session> session) {
        return session.thenApply(Session::getCluster);
    }

    @Provides
    @Singleton
    public CompletionStage<Session> provideCassandraSession(CassandraSession sessionWrapper) {
        CompletableFuture<Session> future = new CompletableFuture<>();
        completeWithSession(sessionWrapper, future);
        return future;
    }

    private void completeWithSession(CassandraSession sessionWrapper, CompletableFuture<Session> future) {
        sessionWrapper.underlying().whenComplete((session, throwable) -> {
            if (throwable != null) {
                if (throwable instanceof NoServiceLocatorException) {
                    log.error("Failed to obtain Cassandra session, try again", throwable);
                    completeWithSession(sessionWrapper, future);
                } else {
                    log.error("Failed to obtain Cassandra session", throwable);
                    future.completeExceptionally(throwable);
                }
            } else {
                log.info("Cassandra session obtained");
                future.complete(session);
            }
        });
    }
}

在某些班级的用法

@Inject
    public CassandraRepository(CompletionStage<MappingManager> mappingManagerPromise, ActorSystem system) {
        this.mappingManagerPromise = mappingManagerPromise;
        this.system = system;
    }



    mappingManagerPromise.thenApply(mappingManager -> {
                    TestAccessor acc = mappingManager.createAccessor(TestAccessor.class);
Result<TestTable> channels = acc.getAll();
                })

如果我使用mapper.getAsync很好。

Mapper<TestTable> mapper = mappingManager.mapper(TestTable.class);
            return toCompletableFuture(mapper.getAsync(id));

在cassandra

0 个答案: