java 为什么 Spring 报告工厂方法 arg 不明确？
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Why does Spring report a factory method arg as ambiguous?
提问by Simeon
I'm trying to create this bean:
我正在尝试创建这个 bean：
<bean id="myBean" class="java.lang.String" factory-method="valueOf">
<constructor-arg name="obj" value="a string" type="java.lang.Object"/>
</bean>
I want Spring to use this method java.lang.String#valueOf(Object obj)when creating the bean.
我希望 Springjava.lang.String#valueOf(Object obj)在创建 bean 时使用这种方法。
I get:
我得到：
Caused by: org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'myBean' defined in class path resource [META-INF/test-contexts/testManualDependencyBundleResolverContext.xml]: Unsatisfied dependency expressed through constructor argument with index 0 of type [char[]]: Ambiguous factory method argument types - did you specify the correct bean references as factory method arguments?
Related cause: org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'myBean' defined in class path resource [META-INF/test-contexts/testManualDependencyBundleResolverContext.xml]: Unsatisfied dependency expressed through constructor argument with index 0 of type [char[]]: Ambiguous factory method argument types - did you specify the correct bean references as factory method arguments?
Related cause: org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'myBean' defined in class path resource [META-INF/test-contexts/testManualDependencyBundleResolverContext.xml]: Unsatisfied dependency expressed through constructor argument with index 0 of type [boolean]: Ambiguous factory method argument types - did you specify the correct bean references as factory method arguments?
Related cause: org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'myBean' defined in class path resource [META-INF/test-contexts/testManualDependencyBundleResolverContext.xml]: Unsatisfied dependency expressed through constructor argument with index 0 of type [long]: Ambiguous factory method argument types - did you specify the correct bean references as factory method arguments?
Related cause: org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'myBean' defined in class path resource [META-INF/test-contexts/testManualDependencyBundleResolverContext.xml]: Unsatisfied dependency expressed through constructor argument with index 0 of type [char]: Ambiguous factory method argument types - did you specify the correct bean references as factory method arguments?
Related cause: org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'myBean' defined in class path resource [META-INF/test-contexts/testManualDependencyBundleResolverContext.xml]: Unsatisfied dependency expressed through constructor argument with index 0 of type [double]: Ambiguous factory method argument types - did you specify the correct bean references as factory method arguments?
Related cause: org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'myBean' defined in class path resource [META-INF/test-contexts/testManualDependencyBundleResolverContext.xml]: Unsatisfied dependency expressed through constructor argument with index 0 of type [float]: Ambiguous factory method argument types - did you specify the correct bean references as factory method arguments?
Related cause: org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'myBean' defined in class path resource [META-INF/test-contexts/testManualDependencyBundleResolverContext.xml]: Unsatisfied dependency expressed through constructor argument with index 0 of type [int]: Ambiguous factory method argument types - did you specify the correct bean references as factory method arguments?
Related cause: org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'myBean' defined in class path resource [META-INF/test-contexts/testManualDependencyBundleResolverContext.xml]: Unsatisfied dependency expressed through constructor argument with index 0 of type [java.lang.Object]: Ambiguous factory method argument types - did you specify the correct bean references as factory method arguments?
Why? I think I've specified everything needed for Spring to resolve the correct method I want it to use.
为什么？我想我已经指定了 Spring 解决我想要它使用的正确方法所需的一切。
回答by Evgeniy Dorofeev
Simply remove nameattribute, XSD docs for name says:
只需删除name属性，名称的 XSD 文档说：
Only needed to avoid ambiguities, e.g. in case of 2 arguments of
the exact same type. Note: This requires debug symbols to be
stored in the class file in order to introspect argument names!
回答by Thihara
I believe the problem is this method valueOf(char[] data)
我相信问题是这种方法 valueOf(char[] data)
You have mentioned argument type as Object.
您已经将参数类型称为 Object。
And char[] is also an Object.
而 char[] 也是一个对象。
回答by Geniy
I had the same problem with a bean like:
我对豆子也有同样的问题：
<bean id="myBean" class="..MyBean">
<constructor-arg ref="bean1/>
<constructor-arg ref="bean2/>
<constructor-arg>
<bean class="MyEnum" factory-method="valueOf">
<constructor-arg value="${configString}"/>
</bean>
</constructor-arg>
<constructor-arg ref="bean3/>
</bean>
To resolve a problem I needed to remove all name attributes like:
要解决一个问题，我需要删除所有名称属性，例如：
<constructor-arg name="arg1" ref="bean1/>
All was worked for me before I moved to java8 and added one additional argument there
在我转向 java8 并在那里添加一个额外的参数之前，一切都对我有用
