为JDBI注册可选

Question

我发现了一个No container builder available for com.google.common.base.Optional错误。

下面是一个更完整的堆栈跟踪：

java.lang.IllegalStateException: No container builder available for com.google.common.base.Optional
    at     org.skife.jdbi.v2.ContainerFactoryRegistry.createBuilderFor(ContainerFactoryRegistry.java:75)
    at org.skife.jdbi.v2.Query.first(Query.java:271)
    at     org.skife.jdbi.v2.sqlobject.ResultReturnThing$SingleValueResultReturnThing.result(ResultReturnThing.java:112)
    at org.skife.jdbi.v2.sqlobject.ResultReturnThing.map(ResultReturnThing.java:48)
    at org.skife.jdbi.v2.sqlobject.QueryHandler.invoke(QueryHandler.java:45)
    at org.skife.jdbi.v2.sqlobject.SqlObject.invoke(SqlObject.java:175)
    at org.skife.jdbi.v2.sqlobject.SqlObject$1.intercept(SqlObject.java:75)
    at org.skife.jdbi.v2.sqlobject.CloseInternalDoNotUseThisClass$$EnhancerByCGLIB$$b270edb1.select(<generated>)

我有一个DAO，它的界面如下：

import com.google.common.base.Optional;

public interface MyDAO {
    @SqlQuery("something")
    Optional<Data> select();
}

以下是我的数据访问层单元测试：

public class MyDAOTest {
    @Test
    public void shouldSelect() {
        DBI dbi = new DBI("jdbc:(something)", "something", "something");
        MyDAO myDAO = dbi.onDemand(MyDAO.class);
        Optional<Data> data = myDAO.select();
        assertFalse(data.absent());
    }
}

Answer 1

如果您使用的是io.dropwizard.jdbi.OptionalContainerFactory，请注册com.google.common.base.Optional并获取错误No container builder available for com.google.common.base.Optional。

如果您使用的是io.dropwizard.java8.jdbi.OptionalContainerFactory，请注册java.util.Optional并获取错误No container builder available for java.util.Optional。

我遵循了这里的指令

public class MyDAOTest {
@Test
public void shouldSelect() {
    DBI dbi = new DBI("jdbc:(something)", "something", "something");
    dbi.registerContainerFactory(new OptionalContainerFactory());
    ...
}

Answer 2

确保在测试代码中创建了一个新的io.dropwizard.java8.jdbi.DBIFactory，而不是io.dropwizard.jdbi.DBIFactory。不幸的是，它们有着相同的名称，而且(根据我的经验)很容易在进口中被忽略。