spring @value returns null

问题

I'm using spring 3.2.2 and what to inject some string in my .properties file into a class. But always get null.

In my applicationContext.xml:

....
<context:component-scan base-package="com.mypackage">
     <context:exclude-filter type="annotation" expression="org.springframework.stereotype.Controller"/
</context:component-scan>
<context:property-placeholder location="classpath:/config/core/abc.properties"/>
....

in abc.properties:

path=testpath

in java code:

package com.mypackage
@Component
public class myclass implements Imyclass {
    @Value("${path}")
    private String path; //this always is null
    ...
    public String getMyPath() {
        return path+"myclass";
    }
}

what I'm missing here?

[Edit]

the reason is in my code someone is calling new Imyclass(). Now there is another class impelement Imyclass:

package com.mypackage
@Component
public class myclass2 implements Imyclass {
    @Value("${path}")
    private String path; //this always is null
    ...
    public String getMyPath() {
        return path+"myclass2";
    }
}

The function calling the Imyclass:

public class myClassContext {
    public static String getPath(...){
        return getImyclass(...).getMyPath();
    }
    private static Imyclass getImyclass(....){
        Imyclass mc=null;
        if (.....) {
            mc=new myclass();
        }
        else{
            mc=new myclass2();
        }
        return state;
    }
}

What's the better way to manage the instance by Spring so the @value will inject correctly?

Do I have to inject both class into myClassContext as a property or use the @Configurable for both myclass and myclass2?

来源：https://stackoverflow.com/questions/37493304/spring-value-returns-null

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