Micronaut：从上下文中获取bean的问题

Question

我有一个包含注入和强制(最终)字段的类。对于common，我可以使用micronatBean factory . get bean(type)或BeanContext.getBean(type)从上下文中获取bean，但是在这种情况下，我必须传递类型和参数。

我为此创建了简单的测试

@MicronautTest
public class ETLExecutorTest {

    @Inject
    private MicronautBeanFactory micronautBeanFactory;

    @Test
    void testGetBean() {
        Object[] args = new Object[] {"name", "spec", 1L};
        ObjectInstance instance = micronautBeanFactory.getBean(ObjectInstance.class, args);
    }
}

对象(bean)代码

@Prototype
public class ObjectInstance {

    @Inject
    private ObjectStorage objectStorage;

    private final String name;
    private final String spec;
    private final Long id;

    public ObjectInstance(String name, String spec, Long id) {
        this.name = name;
        this.spec = spec;
        this.id = id;
    }
}

当我运行它时，我收到异常

io . micro naut . context . exceptions . dependency injectionexception:无法为类com的参数[name]注入值。ObjectInstance消息:找到多个可能的bean候选项:[java.lang.String，java.lang.String，java.lang.String]采用的路径:在io . micron aut . context . abstractbeandition . getbeanforconstructorargument(abstractbeandition . Java:1016)处新建ObjectInstance([String name]，String specName，Long accountId)。在io . micro naut . context . defaultbean context . docreate bean(defaultbean context . Java:1598)在io . micro naut . context . defaultbean context . getscopedbean for definition(defaultbean context . Java:2076)在io . micro naut . context . defaultbean context . getbean for definition(defaultbean context . Java:1991)在

我还试图做另一个测试，但在这种情况下，我接收的对象没有注入的字段

@MicronautTest
public class ETLExecutorTest {

    @Inject
    private BeanContext beanContext;

    @Test
    void testGetBean() {
        Object[] args = new Object[] {"name", "spec", 1L};
        BeanDefinition<ObjectInstance> definition = beanContext.getBeanDefinition(ObjectInstance.class);
        ObjectInstance instance =  definition.getConstructor().invoke(args); // there are no injections here: ObjectStorage of instance = null.
    }
}

你能告诉我，我做错了什么吗？？？

Answer 1

micronaut 试图通过构造函数创建 Bean ObjectInstance，但找不到要注入的 String 名称，看起来它只是 ObjectInstance 的一个简单字段，在这种情况下，它按预期工作：

io . micro naut . context . exceptions . dependency injectionexception:无法为参数[name]注入值

如果您添加默认构造函数，则将创建 ObjectInstance，您可以通过 beanContext.getBean（ObjectInstance.class） 获取 bean：

@Prototype
public class ObjectInstance {

    @Inject
    private ObjectStorage objectStorage;

    private String name;
    private String spec;
    private Long id;


    public ObjectInstance() {}

    public ObjectInstance(String name, String spec, Long id) {
        this.name = name;
        this.spec = spec;
        this.id = id;
    }

}

还要注意MicronautBeanFactory实现了ListableBeanFactory，这是为了与< code>Spring集成

附言：我建议您更改代码结构，POJO不应包含bean