在Dropwizard中注册资源

Question

我无法在Dropwizard应用程序的run()方法中注册多个资源。当我这样做时，我得到了以下异常：

Exception in thread "main" MultiException[java.lang.IllegalArgumentException: A metric named io.dropwizard.db.ManagedPooledDataSource.postgresql.active already exists, java.util.concurrent.RejectedExecutionException: org.eclipse.jetty.util.thread.NonBlockingThread@27f74733]
at org.eclipse.jetty.server.Server.doStart(Server.java:329)
at org.eclipse.jetty.util.component.AbstractLifeCycle.start(AbstractLifeCycle.java:68)
at io.dropwizard.cli.ServerCommand.run(ServerCommand.java:43)
at io.dropwizard.cli.EnvironmentCommand.run(EnvironmentCommand.java:43)
at io.dropwizard.cli.ConfiguredCommand.run(ConfiguredCommand.java:76)
at io.dropwizard.cli.Cli.run(Cli.java:70)
at io.dropwizard.Application.run(Application.java:73)
at com.xxx.xxx.yyy.GobblerHTTPApplication.main(GobblerHTTPApplication.java:19)

Answer 1

似乎您正在为每个资源初始化两次Postgres实例，这并不是必需的。你可以简单地先初始化所有的存储，然后注册你的资源。如下所示：

    /* Service manager */
    environment.lifecycle().manage(new XYZServiceManager());

    /* Adding Resources */
    environment.jersey().register(new FirstResource());
    environment.jersey().register(new SecondResource());

希望这能解决你的问题。

Answer 2

如果你碰巧使用Hibernate初始化数据库，例如。通过在主应用程序中使用以下代码段(两次)：

private final HibernateBundle<Cfg> hib1 = new HibernateBundle<Cfg>(ImmutableList.of(SomeHibernateModel.class), new SessionFactoryFactory()) {
    @Override
    public DataSourceFactory getDataSourceFactory(Cfg configuration) {
        return configuration.getDatabaseFactory();
    }
};

然后重写另一个方法是很有帮助的：“name()”方法。该方法是提供指标名称的最后一部分(´.postgresql.active‘部分)的源，例如：

private final HibernateBundle<Cfg> hib1 = new HibernateBundle<Cfg>(ImmutableList.of(SomeHibernateModel.class), new SessionFactoryFactory()) {
    @Override
    public DataSourceFactory getDataSourceFactory(Cfg configuration) {
        return configuration.getDatabaseFactory();
    }
    @Override
    protected String name() {
        return "hibernate.accesslog";
    }

};