Java Spring 注解问题

发布于 2024-11-26 04:04:19 字数 621 浏览 2 评论 0原文

我对春天有疑问。我正在用基于注释的配置替换基于 xml 文件的 spring 配置。因此我遇到了以下问题。有一个类，其中一个字段是通过基于类的自动装配来配置的。迄今为止，只有一名候选人。但现在有不止一个候选者，因为我已将 @Named 标记添加到同一接口的多个类中。

这是一个代码示例：具有自动装配字段的类：

public class AutowiringClass<X, Y> {
    // This is the field which is autowired
    private Autowired<X, Y> bean;
    .....
}

然后是第二个类，它使用特定的泛型参数扩展 AutoWiringClass：

public class TestClass extends AutoWiringClass<ObjectX, ObjectY> {
    .....
}

问题是，spring 不知道它应该使用哪个类，因为有多个 Autowiring 类型的类，但是具有不同的泛型类型（ObjectX、ObjectY）。我认为，不同的泛型类型可以做到这一点..但他们没有:( 如果有人能找到解决方案，那就太棒了。

原文

I've a problem with spring. I'm replacing the xml file based configuration of spring with annotation based configuration. Because of that I runned into the following problem. Theres is a class, where one field is configured by class based autowiring. Since yet, there has been only one candidate. But now there is more then one candidate, because I've added the @Named tag to mutliple classes of the same interface.

Here is a code example:
The class with the autowiring field:

public class AutowiringClass<X, Y> {
    // This is the field which is autowired
    private Autowired<X, Y> bean;
    .....
}

Then there is a second class, which extends AutoWiringClass with specific generic arguments:

public class TestClass extends AutoWiringClass<ObjectX, ObjectY> {
    .....
}

The Problem is, that spring doesn't know which class it should use, since there are more than once class of the type Autowiring but with different generic types (ObjectX, ObjectY). I thought, that the different generic types will do the thing.. but they doesn't :(
It would be awesome if anybody has an solution for that.

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雪花飘飘的天空 2024-12-03 04:04:19

限定符是什么你正在寻找。当您将一个类注册为 Spring bean（使用 @Component 等）时，您可以将名称作为参数传递。然后，当您自动装配属性时，添加带有该 bean 名称的 @Qualifier 注释。所以：

@Component("Test1")
public class Test { }
@Component("Test2")
public class BetterTest extends Test {}

public class TestUser {
  @Autowired
  @Qualifier("Test1")
  private Test test;
}

Qualifiers are what you are looking for. When you register a class as a Spring bean (using @Component or the like) you can pass a name as an argument. Then when you are autowiring a property, add a @Qualifier annotation with that bean's name. So:

@Component("Test1")
public class Test { }
@Component("Test2")
public class BetterTest extends Test {}

public class TestUser {
  @Autowired
  @Qualifier("Test1")
  private Test test;
}

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