Spring：将属性作为值注入注释

Question

我试图向自定义注释中注入一个值，但Spring似乎没有进行评估。

@Target(ElementType.METHOD)
@Retention(RetentionPolicy.RUNTIME)
public @interface MyCustomAnno {
    String var1();
    String var2();
}

public class MyClass {

    @MyCustomAnno(var1 = "${some.property.one}",
                  var2 = "${some.property.two}")
    public void someMethod() {
    // do something here
    }
}

@Aspect
public class MyAop {

    @Around(value="@annotation(myCustomAnno)",argNames="myCustomAnno")
    public Object aroundMethod(MyCustomAnno myCustomAnno) {
        int intVar1 = Integer.parseInt(myCustomAnno.var1());
        int intVar2 = Integer.parseInt(myCustomAnno.var2());

        // ....
    }
}

@Value("${some.property.one}")
private propertyOne;            // This works

Answer 1

AFAIK,占位符在自定义批注中不解析。但是，您可以在方面本身中解决它们。

例如：

@Aspect
class MyAop implements EmbeddedValueResolverAware {

    private StringValueResolver resolver;

    @Around(value="@annotation(myCustomAnno)",argNames="myCustomAnno")
    public void play(MyCustomAnno ann) {
        System.out.println(resolver.resolveStringValue(ann.var1()));
    }

    @Override
    public void setEmbeddedValueResolver(StringValueResolver resolver) {
        this.resolver = resolver;
    }
}