为什么我们使用 <cxf:rsServer>与普通的 <jaxrs:server> 不同.使用 CXF-RS 组件时?
作为this question的后续,我仍然对如何正确使用CXF-RS有点困惑组件.
As a follow-up to this question, I'm still a bit confused about how to properly use the CXF-RS component.
当我可以使用 <jaxrs:server>
标签非常好.
I'm confused why we need the <cxf:rsServer>
tag for specifying CXF-RS endpoints (or is there even such a concept?), when I can use the <jaxrs:server>
tag perfectly fine.
这是我对 Camel 和 CXF 的配置 XML:
Here's my configuration XML for both Camel and CXF:
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:context="http://www.springframework.org/schema/context"
xmlns:jaxrs="http://cxf.apache.org/jaxrs"
xmlns:camel="http://camel.apache.org/schema/spring"
xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd
http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd
http://cxf.apache.org/jaxws http://cxf.apache.org/schemas/jaxws.xsd
http://cxf.apache.org/transports/http/configuration http://cxf.apache.org/schemas/configuration/http-conf.xsd
http://cxf.apache.org/jaxrs http://cxf.apache.org/schemas/jaxrs.xsd
http://camel.apache.org/schema/spring http://camel.apache.org/schema/spring/camel-spring.xsd">
<jaxrs:server id="userService" address="/users">
<jaxrs:serviceBeans>
<bean class="com.example.UserServiceNoop" />
</jaxrs:serviceBeans>
<jaxrs:providers>
<bean class="org.codehaus.jackson.jaxrs.JacksonJaxbJsonProvider" />
</jaxrs:providers>
</jaxrs:server>
<bean id="user" class="org.apache.camel.component.direct.DirectComponent" />
<camel:camelContext id="someCamelContext">
<camel:route id="userServiceRoute">
<camel:from uri="cxfrs:bean:userService" />
<camel:routingSlip>
<camel:simple>user:${header.operationName}</camel:simple>
</camel:routingSlip>
</camel:route>
<camel:route id="userServiceRetrieveUser">
<from uri="user:retrieveUser" />
<!-- Assume this is going to a useful Processor -->
</camel:route>
</camel:camelContext>
</beans>
UserService.java:
UserService.java:
package com.example;
/* a bunch of imports... */
public interface UserService {
@GET
@Path(value="/{user.id}")
@Produces({MediaType.APPLICATION_JSON})
public User retrieveUser(
@PathParam("user.id") Integer id
);
}
UserServiceNoop.java
UserServiceNoop.java
package com.example;
/* a bunch of imports ... */
public class UserServiceNoop implements UserService
{
@Override
public User retrieveUser(Integer id) {
throw new RuntimeException();
}
}
在这个例子中,我没有使用任何 <cxf:rsServer>
标签,但它工作正常.我知道它通过 CXF-RS 组件,因为当我运行应用程序时,它不会抛出任何 RuntimeExceptions
,这是使用 CXF-RS 时的预期行为(服务中的方法实现类不会被调用).
In this example, I'm not using any <cxf:rsServer>
tag, yet it works fine. I know it goes through the CXF-RS component, because when I run the application, it doesn't throw any RuntimeExceptions
, which is the expected behavior when using CXF-RS (the method implementation in the service class will not be called).
不使用这个标签是不是我错过了什么?
Am I missing something by not using this tag?
推荐答案
正如另一个答案所说, cxf:rsServer
主要用于由 Camel 路由处理,如 jaxrs:server
请求的处理由经典控制器完成.
As the other answer says, the cxf:rsServer
is mainly used to be processed by a Camel route as in the jaxrs:server
the processing of the request is done by a classic controller.
例如:
- 经典 JAXRS 服务器:
您将声明一个经典的 Bean Rest(控制器)并在其中注入一个服务.
You will declare a classic Bean Rest (Controller) and inject a Service inside.
XML 配置示例(摘录):
<jaxrs:server id="deviceServiceSvcV1" address="/device/v1">
<jaxrs:serviceBeans>
<ref component-id="deviceServiceRest" />
</jaxrs:serviceBeans>
<!-- and other providers, interceptors, etc... here -->
</jaxrs:server>
<!-- Service bean -->
<bean id="deviceServiceRest" class="org.mycomp.device.rest.v1.ws.api.DeviceServiceRest">
<property name="deviceService" ref="deviceService" />
</bean>
Controller 类将以经典方式处理请求/响应(例如调用注入服务).
The Controller class will process the request / response in a classic way (e.g. calling an injected service).
cxf:rsServer
的骆驼路线
- Camel route with
cxf:rsServer
XML 配置示例(摘录):
<cxf:rsServer id="rsServer" address="/device/v1"
serviceClass="org.mycomp.device.rest.v1.ws.api.DeviceServiceRest">
<cxf:properties>
<!-- whatever here -->
</cxf:properties>
<!-- and other interceptors, etc... here -->
</cxf:rsServer>
在课堂上:
@Produces({ MediaType.APPLICATION_XML })
@Path("/")
public class DeviceServiceRest {
@GET
public Response listDevicess(
@QueryParam("model") String model,
@QueryParam("sid") String sid,
) {
return null; // never used
}
@GET
@Path("{id}")
public Response getDeviceById(
@PathParam("id") String id,
@QueryParam("model") String model,
@QueryParam("sid") String sid
){
return null; // never used
}
}
REST 控制器有空方法(返回 null),但我认为最新的 camel-cxf
现在支持 Interface
,它比返回 的方法更优雅空
.现在,请求处理可以通过 Camel Route 来实现,如下所示:
The REST Controller has empty methods (returning null) but I think the latest camel-cxf
supports now an Interface
which is more elegant than having methods returning null
.
Now, the request processing can be implemented by a Camel Route like this:
from("cxfrs:bean:rsServer?synchronous=true")
.routeId("cxf-device-rest-v1")
.process( new CheckAuthenticationProcessor())
.choice()
.when(header("operationName").isEqualTo("listDevice"))
.setHeader("backenOperation").constant("list")
.setHeader("backendResource").constant("device")
.endChoice()
.when(header("operationName").isEqualTo("getDeviceById"))
.setHeader("backenOperation").constant("retrieve")
.setHeader("backendResource").constant("device")
.endChoice()
.end()
.bean("requestProcessor")
.to(InOut, backendEndpoint)
.process(checkResponseStatusCode())
.bean(new HttpResponseProcessor())
;
您还可以从路由中根据需要控制请求/响应处理.
And you can also control the request / response processing as you want from the route.
这是两种不同的实现 REST API(服务器端)的方式,但在我看来这有点老派,因为像 spring-boot 这样的现代框架不需要这些.
These are two different kind of implementing a REST API (server side) but in my opinion this is a bit old school as modern framework like spring-boot does not need any of these.
我发现第二种方法有点矫枉过正,因为我喜欢 Camel 用于集成目的,但将它用于 REST API 可能需要讨论.我可以看到的一个用例是用于异步处理的 HTTP REST Web 服务,响应 202 Accepted 的服务和 Camel Route 在异步模式下集成请求,特别是当可以轻松使用特定的 Camel 组件而不是复杂的组件时类(或任何需要 EIP 模式).
I found the second way a bit too much overkill as I like Camel for integration purpose but using it for a REST API could be subject to discussion. One use-case I can see is a HTTP REST Web-Service for asynchronous processing, the service responding 202 Accepted and the Camel Route making an integration of the request in asynchronous mode especially when a specific Camel Component can be easily used instead of a complex class (or any need of the EIP patterns).
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