Spring Autowiring仅适用于Interface [英] Spring Autowiring only works with Interface

问题描述

我对spring框架很新，遇到了以下问题。

I am quite new to spring framework and came across the following issue.

我有一个接口 ClassA ，由分类 ClassA1 和 ClassA2 实现。

I have an interface ClassA, which is implemented by classed ClassA1 and ClassA2.

我将以下bean定义添加到 applicationContext.xml

I have the following bean definition added to applicationContext.xml

<bean id="class1" class="com.abc.ClassA1" />
<bean id="class2" class="com.abc.ClassA2" />

我想将两个实现类自动装配如下。

I would like to Autowire both the implementation classes as below.

@Autowired
private ClassA1 classA1;

@Autowired
private ClassA2 classA2;

上面的代码抛出错误

无法自动写入字段：com.abc.ClassA1 com.abc.SomeClass.classA1;嵌套异常是
org.springframework.beans.factory.NoSuchBeanDefinitionException：
没有匹配的
类型的bean [com.abc.ClassA1]

Could not autowrite to field: com.abc.ClassA1 com.abc.SomeClass.classA1; nested exception is org.springframework.beans.factory.NoSuchBeanDefinitionException: No matching bean of type [com.abc.ClassA1]

但是，如果我将自动装配更改为接口，如下所示：

But, if I change the autowiring to interface as below:

@Autowired
ClassA classA1;

然后ClassA1自动连接到变量。我无法知道如何将变量自动装配到ClassA2。

Then ClassA1 is autowired to the variable. I am clueless on how can I autowire a variable to ClassA2.

推荐答案

我尝试了多种方法来解决这个问题，但我得到了它按以下方式工作。

I tried multiple ways to fix this problem, but I got it working the following way.

@Autowired
private ClassA classA1;

@Autowired
private ClassA classA2;

在应用程序上下文中，我将bean定义如下：

In the application context, I defined the bean as below:

<bean id="classA1" class="com.abc.ClassA1" autowire="byName" />
<bean id="classA2" class="com.abc.ClassA2" autowire="byName" />

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