java - 在 ContainerRequestFilter 中获取资源类注释值

Question

我有点难以理解其余拦截器注释如何添加不同的值，这些值稍后会在过滤器中可见。鉴于下面的代码，我希望一旦进入过滤器，权限值就会包含 foo 和 bar，但它们是空的。任何帮助将不胜感激。

注释

package edu.psu.swe.fortress.poc.interceptor;

import java.lang.annotation.ElementType;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;

import javax.enterprise.util.Nonbinding;
import javax.ws.rs.NameBinding;

@NameBinding
@Target({ElementType.TYPE, ElementType.METHOD})
@Retention(value=RetentionPolicy.RUNTIME)
public @interface FortressProtected
{
  @Nonbinding String[] permissions() default {};
}

过滤器

package edu.psu.swe.fortress.poc.interceptor;

import java.io.IOException;
import java.lang.annotation.Annotation;

import javax.ws.rs.container.ContainerRequestContext;
import javax.ws.rs.container.ContainerRequestFilter;
import javax.ws.rs.ext.Provider;

@Provider
@FortressProtected
public class FortressAuthorizer implements ContainerRequestFilter
{

  @Override
  public void filter(ContainerRequestContext requestContext) throws     IOException
  {
    System.out.println("In the interceptor");
    Class<?> clazz = this.getClass();
    FortressProtected annotation = clazz.getAnnotation(edu.psu.swe.fortress.poc.interceptor.FortressProtected.class);

    System.out.println("Annotation? " + clazz.isAnnotation());

    for (Annotation a : clazz.getAnnotations())
    {
      System.out.println(a);
    }

    for (String s : annotation.permissions())
    {
      System.out.println(s);
    }
  }
}

应用配置

package edu.psu.swe.fortress.poc.rest;

import java.util.HashSet;
import java.util.Set;

import javax.ws.rs.ApplicationPath;
import javax.ws.rs.core.Application;

import edu.psu.swe.fortress.poc.interceptor.FortressAuthorizer;
import edu.psu.swe.fortress.poc.interceptor.FortressProtected;

@ApplicationPath("")
public class FortressTestApp extends Application
{
  private Set<Class<?>> clazzez_ = new HashSet<>();
  {
    clazzez_.add(ResourceImpl.class);
    clazzez_.add(FortressProtected.class);
    clazzez_.add(FortressAuthorizer.class);
  }
  public Set<Class<?>> getClasses()
  {
    return clazzez_;
  }
}

资源类

package edu.psu.swe.fortress.poc.rest;

import javax.ws.rs.GET;
import javax.ws.rs.Path;
import javax.ws.rs.Produces;

import edu.psu.swe.fortress.poc.interceptor.FortressProtected;

@FortressProtected(permissions={"foo", "bar"})
@Path("tests")
public class ResourceImpl
{
  @GET
  @Produces("application/text")
  public String getHello()
  {
    FortressProtected annotation = this.getClass().getAnnotation(edu.psu.swe.fortress.poc.interceptor.FortressProtected.class);

    System.out.println(annotation.toString());

    return "hello";
  }
}

日志输出如下:

15:59:55,223 INFO [stdout] (default task-9) @edu.psu.swe.fortress.poc.interceptor.FortressProtected(permissions=[]) 15:59:55,229 INFO [stdout] (default task-9) @edu.psu.swe.fortress.poc.interceptor.FortressProtected(permissions=[foo, bar])

提前致谢。

Answer 1

在你的过滤器中查看这个

Class<?> clazz = this.getClass();
FortressProtected annotation = clazz.getAnnotation(FortressProtected.class);

this.getClass() 对应于过滤器类(其注解没有值)。相反，您需要在 ResourceImpl

上获取注解

几个选项。您可以显式使用 ResourceImpl.class.getAnnotation(...)。但是这样做的问题是，一旦你绑定(bind)了多个类，你怎么匹配哪个类对应哪个请求。因此，下一个选项更可行。

你所做的是注入(inject) ResourceInfo .有了它，您可以调用它的 getResourceMethod 或 getResourceClass 方法。这些方法分别返回匹配的方法和类。然后，您可以在类级别和方法级别检查注释(因为我们也可以在方法级别进行绑定(bind))。所以你可能有更像的东西:

@Provider
@FortressProtected
public class FortressAuthorizer implements ContainerRequestFilter {

  @Context
  ResourceInfo resourceInfo;

  @Override
  public void filter(ContainerRequestContext requestContext) throws IOException {

    Class<?> resourceClass = resourceInfo.getResourceClass();
    FortressProtected classAnnot = resourceClass.getAnnotation(FortressProtected.class);
    if (classAnnot != null) {
      // do something with annotation
    }

    Method resourceMethod = resourceInfo.getResourceMethod();
    FortressProtected methodAnnot = resourceMethod.getAnnotation(FortressProtected.class);
    if (methodAnnot != null) {
      // do something with annotation
    }
  }
}