Spring：将属性作为值注入注释

我试图向自定义注释中注入一个值，但Spring似乎没有进行计算

这是我的注解：

@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());

        // ....
    }
}

这是我的Bean，它是在带有注释的Spring配置文件中创建的：

@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());

        // ....
    }
}

以下是我尝试使用传递到注释中的值的方面：

@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());

        // ....
    }
}

在around方法中，我接收到一个NumberFormatException:对于输入字符串：${some.property.one}。这意味着Spring出于某种原因没有注入该值

如果您想知道，在同一个类中，我可以进行正常的@Value注释，并且正确地注入值：

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

---

是否可以执行我想执行的操作？如果可以，如何执行？

好的，占位符在自定义注释中不会解析。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;
    }
}