Guice配置错误:未绑定任何实现

时间:2010-12-27 16:45:16

标签: java dependency-injection guice

我正在尝试使用Guice工作制作DI,对我来说(在我看来)正是the manual中的内容。

我无法解释这个问题,因为我并不真正理解它 - 一切看起来都非常符合逻辑并应该有效......但事实并非如此。所以,我只能附加代码和堆栈跟踪:

public class Runner {

    public static void main(String[] args) {
        Injector injector = Guice.createInjector(new TestModule());
        //next line throws the exception
        JMeterComponent jMeterComponent = 
             injector.getInstance(JMeterComponent.class);
        ....
    }
}

如您所见,我正在尝试实例化JMeterComponent类的对象。它的构造函数(稍后会看到)接受3个参数:它们都应该由IoC实例化并注入。

这是TestModule配置这3个参数:

public class TestModule extends AbstractModule {

    @Override
    protected void configure() {
        bind(Callable.class).annotatedWith(Names.named("JMeter"))
                  .to(JMeterTask.class);      
        bind(Processor.class).annotatedWith(Names.named("JMeter"))
                  .to(JMeterResultsProcessor.class);
        bind(Renderer.class).annotatedWith(Names.named("JMeter"))
                  .to(JMeterResultsWikiRenderer.class);
    }
}

现在,让我们看看那些具体的实现 - JMeterTaskJMeterResultsProcessorJMeterResultsWikiRenderer(为简单起见,所有这些实体都有假身体):

public class JMeterTask implements Callable<JMeterRawResults> {

    public JMeterRawResults call() throws Exception {
        return new JMeterRawResults();
    }
}

public class JMeterResultsProcessor implements 
                   Processor<JMeterRawResults, JMeterResults> {

    public JMeterResults process(JMeterRawResults raw) {
        return new JMeterResults();
    }
}

public class JMeterResultsWikiRenderer implements Renderer<JMeterResults> {

    public Map<String, String> render(JMeterResults jMeterResults) {
        Map<String, String> results = Maps.newHashMap();
        ...
        return results;
    }
}

现在让我们看一下JMeterComponent类,这个实例的构造是整个DI相关内容的目标:

public class JMeterComponent extends AbstractComponent<String, String> {

    @Inject
    public JMeterComponent(@Named("JMeter") Callable<String> task, 
                           @Named("JMeter")Processor<String, String> processor, 
                           @Named("JMeter")Renderer<String> renderer) {
        super(task, processor, renderer);
    }
}

这是堆栈跟踪:

Exception in thread "main" com.google.inject.ConfigurationException: Guice configuration errors:

1) No implementation for stat.domain.Processor<java.lang.String, java.lang.String> annotated with @com.google.inject.name.Named(value=JMeter) was bound.
  while locating stat.domain.Processor<java.lang.String, java.lang.String> annotated with @com.google.inject.name.Named(value=JMeter)
    for parameter 1 at stat.components.jmeter.JMeterComponent.<init>(JMeterComponent.java:18)
  while locating cstat.components.jmeter.JMeterComponent

2) No implementation for stat.domain.Renderer<java.lang.String> annotated with @com.google.inject.name.Named(value=JMeter) was bound.
  while locating stat.domain.Renderer<java.lang.String> annotated with @com.google.inject.name.Named(value=JMeter)
    for parameter 2 at stat.components.jmeter.JMeterComponent.<init>(JMeterComponent.java:18)
  while locating stat.components.jmeter.JMeterComponent

3) No implementation for java.util.concurrent.Callable<java.lang.String> annotated with @com.google.inject.name.Named(value=JMeter) was bound.
  while locating java.util.concurrent.Callable<java.lang.String> annotated with @com.google.inject.name.Named(value=JMeter)
    for parameter 0 at stat.components.jmeter.JMeterComponent.<init>(JMeterComponent.java:18)
  while locating stat.components.jmeter.JMeterComponent

其他一些事实:

  1. 我使用的是guice-2.0(featured 标签)
  2. 代码中任何其他类的com.google.inject包中都没有任何注释
  3. 接口ProcessorRenderer放置在一个模块中,其jmeter - 实现(JMeterResultsProcessor和其他)和JMeterComponent类放在另一个模块中模块。
  4. 这几乎是关于它的所有内容。

    很抱歉这么长的帖子,感谢您的耐心阅读到最后。

    关于错误发生原因以及解决方法的任何想法?

1 个答案:

答案 0 :(得分:14)

我在这里看到了几个问题。

首先,CallableCallable<String>不同。如果您想在Guice中注入Callable<String>(或Processor<String, String>等),则必须将某些内容绑定到Callable<String>,而不是Callable

其次,你将Callable绑定到实现JMeterTask的{​​{1}},但是你在Callable<JMeterRawResults>的构造函数中注入Callable<String>(同样的交易) JMeterComponentProcessor)。我将假设Renderer应注入JMeterComponent等。

无论如何,您需要做的是使用Callable<JMeterRawResults> 泛型绑定:

TypeLiteral