[英]Spring framework 4 Generic class dependency autowire is not working
[英]How to Autowire generic class using Spring 4?
我的課程如下:
class Foo<KeyType, ValueType> {
private Producer<KeyType, ValueType> kafkaProducer;
public Foo() {
this.kafkaProducer = new Producer<KeyType, ValueType>(new ProducerConfig());
}
}
還有另一個使用此Foo類的DAO類,如下所示:
class CompanyDao {
@Autowired
private Foo<String, Integer> fooHelper;
}
我希望Spring在fooHelpder
對象中注入Foo
類型的對象。 為此我使用以下XML配置:
<bean id="fooHelper" class="com.ask.util.Foo">
<property name="KeyType" value="java.lang.String" />
<property name="ValueType" value="Integer" />
</bean>
<bean id="CompanyDao" class="com.ask.dao.CompanyDao">
<property name="fooHelper"><ref bean="fooHelder"/></property>
</bean>
當我使用這個XML配置時,Spring會拋出以下錯誤:
org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'fooHelper' defined in class path resource [applicationContext.xml]: Error setting property values; nested exception is org.springframework.beans.NotWritablePropertyException: Invalid property 'KeyType' of bean class [com.ask.util.fooHelper]: Bean property 'KeyType' is not writable or has an invalid setter method. Does the parameter type of the setter match the return type of the getter?
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.applyPropertyValues(AbstractAutowireCapableBeanFactory.java:1361)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1086)
知道如何解決這個錯誤嗎?
需要進行兩項更改。
第一個是因為Spring 4現在在注入期間使用Generics(Pre Spring 4版本忽略了泛型):
class CompanyDao {
private Foo<KeyType, ValueType> fooHelper;
}
(使用XML配置時不需要注釋)
和
<bean id="fooHelper" class="com.ask.util.Foo">
</bean>
<bean id="CompanyDao" class="com.ask.dao.CompanyDao">
<property name="fooHelper"><ref bean="fooHelder"/></property>
</bean>
使用setter方法將KeyType和ValueType屬性添加到您的類。
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