java – Dropwizard请求使用URI模式的过滤器

2019年7月20日 219次阅读

我正在Dropwizard中构建一个RESTful应用程序.连接到数据库时,我想设置一个实现ContainerRequestFilter的UserNotFoundFilter,以便传入的请求首先通过此过滤器.

我的想法是,我希望这个特定的过滤器只映射到某些URI模式.例如,我希望过滤器仅适用于/ users / *而不是其他任何内容.有没有办法在不使用DynamicFeature的自定义注释和实现的情况下执行此操作？

@Provider
public class UserNotFoundFilter implements ContainerRequestFilter {
    @Context
    UriInfo uriInfo;

    @Override
    public void filter(ContainerRequestContext requestContext) throws IOException {
        MultivaluedMap pathParams = uriInfo.getPathParameters(); // Should contain (uid: 1) pair for /users/1
        boolean userExists = // check against the database using above pathparam pair to see if user exists
        if (!userExists) 
            throw new WebApplicationException("User does not exist", Status.NOT_FOUND);
        // let the request through as user exists
    }
}

我的UserResource类

public class UserResource {
    @GET
    @Path("/users/{uid}")
    @Produces(MediaType.APPLICATION_JSON)
    public User getUser(@PathParam("uid") String uid) {
        // Now I don't need to do the check here !
        // boolean userExists = check against database using uid path param
        // if (!userExists)
        //     throw new WebApplicationException("User does not exist", Status.NOT_FOUND);
        return database.getUser(uid);
    }
}

我的ItemResource类

public class ItemResource {
    @GET
    @Path("/items/{uid}")
    @Produces(MediaType.APPLICATION_JSON)
    public Item getItem(@PathParam("uid") String uid) {
        return database.getItem(uid);
    }
}

我想做什么

public class MyApplication extends Application<MyConfiguration> {
    // ...
    @Override
    public void run(MyConfiguration config, Environment environment) throws Exception {
        // ... do other things, register resources
        // this pseudocode, the UserNotFoundFilter only applies to URIs of the kind /users/*
        environment.jersey().register(new UserNotFoundFilter()).forUriPattern("/users/*");

我感谢任何示例代码片段.

最佳答案 对于Servlet过滤器 –

可能你正在寻找的是来自javax.servlet.FilterRegistration接口的addMappingForUrlPatterns,用于你的run()as –

 environment.servlets().addFilter("FilterName", UserNotFoundFilter.class)
          .addMappingForUrlPatterns(EnumSet
                         .allOf(DispatcherType.class), true, "/users/*");

上述方法的签名是 –

public void addMappingForUrlPatterns(
        EnumSet<DispatcherType> dispatcherTypes, boolean isMatchAfter,
        String... urlPatterns);

编辑 – 动态绑定：

尝试使用DynamicFeature作为

@Provider
public class UserNotFoundDynamicFilter implements DynamicFeature {

    @Override
    public void configure(ResourceInfo resourceInfo, FeatureContext featureContext) {
       if (resourceInfo.getResourceMethod().getAnnotation(UserRequired.class) != null) {
          featureContext.register(UserNotFoundFilter.class);
       }
    }
}

您可以在其中将UserRequired注释定义为 –

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

@Target(ElementType.METHOD)
@Retention(RetentionPolicy.RUNTIME)
public @interface UserRequired {
}

并在您的资源中标记所有/ users / * apis具有相同的注释 –

@GET
@Path("/users/{uid}")
@Produces(MediaType.APPLICATION_JSON)
@UserRequired
public User getUser(@PathParam("uid") String uid) {
    // Now I don't need to do the check here !
    // boolean userExists = check against database using uid path param
    // if (!userExists)
    //     throw new WebApplicationException("User does not exist", Status.NOT_FOUND);
    return database.getUser(uid);
}

来源 – jersey-filters

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