未找到宁静的 Web 服务公共构造函数

Question

我正在尝试使用客户端 Web 应用程序调用 RESTful Web 服务（来自 JSF MB 的简单客户端请求）。我需要为 web 服务创建一个接口，然后调用其中的方法。但是如果我在接口上使用@Path，它会给出一个错误——在 Jboss 部署期间找不到公共构造函数。但是如果我在实现类给@Path。它调用服务很好并且工作正常。我需要在 Rest 客户端和 Restful webservice impl 类之间有一个 Java 接口。任何人都可以帮忙吗？我们可以有 Rest 接口吗？

客户端：

ClientRequest request = new ClientRequest("localhost:8080/RESTfulExample/json/...../"); 
ClientResponse<String> response = request.get(String.class);

休息接口：

package com.nee.interfaces; 
import javax.ws.rs.Path; 
import javax.ws.rs.GET; 

@Path("/OrderManagementService") 
public interface OrderManagementServiceInterface { 
    @GET
    @Path("/GetListOfOrders") 
    void getListOfOrders(); 
}

实施：

package com.nee.implementations;
import com.nee.interfaces.OrderManagementServiceInterface;


public class OrderManagementServiceImpl implements OrderManagementServiceInterface {
    public void getListOfOrders() {
        System.out.println("am here");
    }
}

web.xml

<?xml version="1.0" encoding="UTF-8"?>
<web-app version="2.4"
    xmlns="http://java.sun.com/xml/ns/j2ee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://java.sun.com/xml/ns/j2ee http://java.sun.com/xml/ns/j2ee/web-app_2_4.xsd">
<context-param>
    <param-name>resteasy.resources</param-name>
    <param-value>
        com.nee.interfaces.OrderManagementServiceInterface
    </param-value>
</context-param>

<!-- this has to match with resteasy-servlet url-pattern -->

<context-param>
    <param-name>resteasy.servlet.mapping.prefix</param-name>
    <param-value>/rest</param-value>
</context-param>

<!-- to return data according to extension -->

<context-param>
    <param-name>resteasy.media.type.mappings</param-name>
    <param-value>json : application/json, xml : application/xml</param-value>
</context-param>

<listener>
    <listener-class>
        org.jboss.resteasy.plugins.server.servlet.ResteasyBootstrap
    </listener-class>
</listener>

<servlet>
    <servlet-name>resteasy-servlet</servlet-name>
    <servlet-class>
        org.jboss.resteasy.plugins.server.servlet.HttpServletDispatcher
    </servlet-class>
</servlet>

<servlet-mapping>
    <servlet-name>resteasy-servlet</servlet-name>
    <url-pattern>/rest/*</url-pattern>
</servlet-mapping>
</web-app>

日志：

[org.apache.catalina.core.ContainerBase.[jboss.web].[default-host].[/web]]
(MSC service thread 1-2) Exception sending context initialized event to listener instance of class
org.jboss.resteasy.plugins.server.servlet.ResteasyBootstrap: java.lang.RuntimeException: Unable to find a public constructor for class com.seagate.interfaces.OrderManagementServiceInterface
at org.jboss.resteasy.plugins.server.resourcefactory.POJOResourceFactory.registered(POJOResourceFactory.java:35) [resteasy-jaxrs-2.3.3.Final-redhat-1.jar:2.3.3.Final-redhat-1]
at org.jboss.resteasy.core.ResourceMethodRegistry.addResourceFactory(ResourceMethodRegistry.java:120) [resteasy-jaxrs-2.3.3.Final-redhat-1.jar:2.3.3.Final-redhat-1]
at org.jboss.resteasy.core.ResourceMethodRegistry.addResourceFactory(ResourceMethodRegistry.java:106) [resteasy-jaxrs-2.3.3.Final-redhat-1.jar:2.3.3.Final-redhat-1]
at org.jboss.resteasy.core.ResourceMethodRegistry.addResourceFactory(ResourceMethodRegistry.java:83) [resteasy-jaxrs-2.3.3.Final-redhat-1.jar:2.3.3.Final-redhat-1]
at org.jboss.resteasy.core.ResourceMethodRegistry.addPerRequestResource(ResourceMethodRegistry.java:72) [resteasy-jaxrs-2.3.3.Final-redhat-1.jar:2.3.3.Final-redhat-1]
at org.jboss.resteasy.spi.ResteasyDeployment.registration(ResteasyDeployment.java:383) [resteasy-jaxrs-2.3.3.Final-redhat-1.jar:2.3.3.Final-redhat-1]
at org.jboss.resteasy.spi.ResteasyDeployment.start(ResteasyDeployment.java:225) [resteasy-jaxrs-2.3.3.Final-redhat-1.jar:2.3.3.Final-redhat-1]
at org.jboss.resteasy.plugins.server.servlet.ResteasyBootstrap.contextInitialized(ResteasyBootstrap.java:28) [resteasy-jaxrs-2.3.3.Final-redhat-1.jar:2.3.3.Final-redhat-1]
at org.apache.catalina.core.StandardContext.contextListenerStart(StandardContext.java:3392) [jbossweb-7.0.16.Final-redhat-1.jar:]
at org.apache.catalina.core.StandardContext.start(StandardContext.java:3850) [jbossweb-7.0.16.Final-redhat-1.jar:]
at org.jboss.as.web.deployment.WebDeploymentService.start(WebDeploymentService.java:90) [jboss-as-web-7.1.2.Final-redhat-1.jar:7.1.2.Final-redhat-1]
at org.jboss.msc.service.ServiceControllerImpl$StartTask.startService(ServiceControllerImpl.java:1811)
at org.jboss.msc.service.ServiceControllerImpl$StartTask.run(ServiceControllerImpl.java:1746)
at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)[rt.jar:1.7.0_09]
at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source) [rt.jar:1.7.0_09]
at java.lang.Thread.run(Unknown Source) [rt.jar:1.7.0_09]

Answer 1

我猜你的错误是你给 RestEasy 一个 interface 并且框架试图通过反射创建它的一个实例。这样的事情永远不会奏效。而不是接口，您应该只指定实现类作为参数resteasy.resources 的值。如果您想更动态地尝试 OSGi 和 REST 的组合。 this 博客中的示例我没有亲自尝试过，但你可以看看。

更新

由于您还想使用来自第三方类的服务，为什么不使用您的 REST Web 服务包装另一个接口，并且该包装的接口可以在您的第三方类中使用。然后，Web 服务仅用于将请求委托给该接口的特定实现。您可以通过 Spring、Google Juice 等依赖注入框架注入实现。这就是我的意思：

您的接口作为实现的抽象：

interface IExecutionService {
   void executeStuff();
}

然后是你的 REST 服务：

@Path("/OrderManagementService")
class ExectionServiceDelegator {

   private IExecutionService wrappedServiceInterface;

   /**
    * play around with some DI frameworks for injecting your implementation
    */
   public void setIExecutionService(IExecutionService service) {
      wrappedServiceInterface = service;    
   }

   @GET
   @Path("/GetListOfOrders") 
   public void doingSomething() {
      service.executeStuff();
   }
}

您也可以在第三方接口中将接口IExecutionService 与特定的DI 框架结合使用。希望很清楚我想用上面的代码做什么？！

Answer 2

上面的问题有一个简单的答案。在 web.xml 中，而不是接口，我只需要配置 IMPL 类而不是接口并继续在接口处设置@Path

<context-param>
    <param-name>resteasy.resources</param-name>
    <param-value>
        com.seagate.implementations.OrderManagementServiceImpl
    </param-value>
</context-param>

它工作了:)...