在 Play 2.6.X 中使用数据库调度程序线程池时出错

Question

我正在使用Play框架2.6.12进行CRUD练习。不知何故，当我在数据模型上运行测试时，记录已成功插入数据库，但出现如下错误：

[error] i.e.s.t.TransactionManager - NotifyOfCommit failed. L2 Cache potentially not notified.
java.util.concurrent.RejectedExecutionException: Task io.ebeaninternal.server.transaction.PostCommitProcessing$$Lambda$572/1466216168@39a29ab4 rejected from java.util.concurrent.ThreadPoolExecutor@7f63572[Terminated, pool size = 0, active threads = 0, queued tasks = 0, completed tasks = 0]
    at java.util.concurrent.ThreadPoolExecutor$AbortPolicy.rejectedExecution(ThreadPoolExecutor.java:2063)
    at java.util.concurrent.ThreadPoolExecutor.reject(ThreadPoolExecutor.java:830)
    at java.util.concurrent.ThreadPoolExecutor.execute(ThreadPoolExecutor.java:1379)
    at io.ebeaninternal.server.lib.DaemonExecutorService.execute(DaemonExecutorService.java:41)
    at io.ebeaninternal.server.core.DefaultBackgroundExecutor.execute(DefaultBackgroundExecutor.java:36)
    at io.ebeaninternal.server.transaction.TransactionManager.notifyOfCommit(TransactionManager.java:338)
    at io.ebeaninternal.server.transaction.JdbcTransaction.notifyCommit(JdbcTransaction.java:927)
    at io.ebeaninternal.server.transaction.JdbcTransaction.flushCommitAndNotify(JdbcTransaction.java:984)
    at io.ebeaninternal.server.transaction.JdbcTransaction.commit(JdbcTransaction.java:1031)
    at io.ebeaninternal.server.transaction.TransactionMap$State.commit(TransactionMap.java:82)

谁能告诉我为什么？

这是我的环境：

• Mac OSX 10.13.3
• MySQL 5.7.18
• JDK 1.8
• JDBC 连接器 5.1.42
• SBT 1.1.1
• 游戏框架 2.6.12
• 智能创意

和我的应用程序.conf文件：

## Database configuration
db {
  default.driver=com.mysql.jdbc.Driver
  default.url="jdbc:mysql://localhost/crud"
  default.username=root
  default.password="Pa55word"
}
## Ebean default server
ebean.default = ["models.*"]
## Public Assets
play.assets {
  path = "/public"
  urlPrefix = "/assets"
}
# Number of database connections
fixedConnectionPool = 9
# Set Hikari to fixed size
play.db {
  prototype {
    hikaricp.minimumIdle = null ##${fixedConnectionPool} or null
    hikaricp.maximumPoolSize = 9 ##${fixedConnectionPool}
  }
}
# Job queue sized to HikariCP Connection Pool
database.dispatcher {
  executor = "thread-pool-executor"
  throughput = 1
  thread-pool-executor {
    fixed-pool-size = 9 ##${fixedConnectionPool}
  }
}

我是否进行了错误的配置？

以下是我的练习代码。

班级人员：

package models;
import io.ebean.Finder;
import io.ebean.Model;
import play.data.validation.Constraints;
import javax.persistence.Entity;
import javax.persistence.Id;
@Entity
public class Person extends Model{
    @Id
    public Long id;
    @Constraints.Required
    public String name;
    public static final Finder<Long, Person> find = new Finder<>(Person.class);
    public Person(String name){
        this.name = name;
    }
}

类人员存储库：

package repository;
import io.ebean.*;
import models.Person;
import play.db.ebean.EbeanConfig;
import javax.inject.Inject;
import java.util.concurrent.CompletionStage;
import static java.util.concurrent.CompletableFuture.supplyAsync;
public class PersonRepository {
    private final EbeanServer ebeanServer;
    private final DatabaseExecutionContext dbec;
    @Inject
    public PersonRepository(EbeanConfig ebeanConfig,
                            DatabaseExecutionContext dbec){
        this.ebeanServer = Ebean.getServer(ebeanConfig.defaultServer());
        this.dbec = dbec;
}
public CompletionStage<Long> insert(Person person){
    return supplyAsync(() -> {
        ebeanServer.insert(person);
        return System.currentTimeMillis(); //just for test
    }, dbec);
}

}

类数据库执行上下文：

package repository;
import akka.actor.ActorSystem;
import play.libs.concurrent.CustomExecutionContext;
import javax.inject.Inject;
public class DatabaseExecutionContext extends CustomExecutionContext{
    @Inject
    public DatabaseExecutionContext(ActorSystem actorSystem){
        super(actorSystem, "database.dispatcher");
    }
}

和测试代码：

import models.Person;
import org.junit.Test;
import play.test.WithApplication;
import repository.PersonRepository;
public class ModelTest extends WithApplication{
    @Test
    public void createPersons(){
        final PersonRepository repo = app.injector().instanceOf(PersonRepository.class);
        Person p1 = new Person("Tom");
        repo.insert(p1);
        Person p2 = new Person("John");
        repo.insert(p2);
        Person p3 = new Person("Peter");
        repo.insert(p3);
    }
}

请帮助我，提前谢谢。

Answer 1

原来我的 build.sbt 文件中有错误。我曾经像这样声明库依赖项：

libraryDependencies ++= Seq(guice, jdbc, ..., ehcache)

但是在我删除"ehcache"后，错误消失了，似乎存在库冲突。