缺少方法 public void 的依赖项答案

【问题标题】：Missing dependency for method public void缺少方法 public void 的依赖项
【发布时间】：2016-03-20 10:44:40
【问题描述】：

我有这个代码：

@Path("/automation/devices")
@Singleton
public class DevicesWebService {
    private AppiumServerManager appiumServerManager;
    private AdbService adbService;
    private DevicesService deviceService;

    public DevicesWebService() {
        this(new AdbServiceLocal(), new AppiumServerManagerLocal());
    }

    @VisibleForTesting
    public DevicesWebService(AdbService adbService, AppiumServerManagerLocal AppiumServerManager) {
        this.adbService = adbService;
        this.appiumServerManager = AppiumServerManager;
    }


    @GET
    @Produces(MediaType.TEXT_PLAIN)
    public String getMessage() {
        return "welocme to devices web-service";
    }

    @POST
    @Consumes({MediaType.APPLICATION_JSON})
    @Produces({MediaType.TEXT_PLAIN})
    @Path("/acquireDevice/{device}/{port}")
    public Response acquireDevice(@PathParam("device") Device device, @PathParam("port") Integer port) throws
            Exception {
        try {
            deviceService.acquireDevice(device, port);
        } catch (RuntimeException e) {
            return Response.status(Response.Status.NOT_FOUND).build();
        }
        return Response.status(Response.Status.OK).build();

    }
//
    public static void main(String[] args) throws IOException {
        HttpServer server = HttpServerFactory.create("http://localhost:9998/");
        server.start();
        System.out.println("Server running");
        System.out.println("Visit: http://localhost:9998/automation/devices");
    }
}

我的代码在运行时失败，出现以下异常：

Mar 20, 2016 12:37:51 PM com.sun.jersey.api.core.ScanningResourceConfig logClasses
INFO: Root resource classes found:
  class com.m.mobileautomation.devices.webServices.DevicesWebService
  class com.m.mobileautomation.MobileAutomationWebService
Mar 20, 2016 12:37:51 PM com.sun.jersey.api.core.ScanningResourceConfig logClasses
INFO: Provider classes found:
  class org.codehaus.jackson.jaxrs.JacksonJaxbJsonProvider
  class org.codehaus.jackson.jaxrs.JacksonJsonProvider
  class org.codehaus.jackson.jaxrs.JsonMappingExceptionMapper
  class org.codehaus.jackson.jaxrs.JsonParseExceptionMapper
Mar 20, 2016 12:37:51 PM com.sun.jersey.server.impl.application.WebApplicationImpl _initiate
INFO: Initiating Jersey application, version 'Jersey: 1.19 02/11/2015 05:39 AM'
Mar 20, 2016 12:37:52 PM com.sun.jersey.spi.inject.Errors processErrorMessages
SEVERE: The following errors and warnings have been detected with resource and/or provider classes:
  SEVERE: Missing dependency for method public javax.ws.rs.core.Response com.m.mobileautomation.devices.webServices.DevicesWebService.acquireDevice(com.m.mobileautomation.devices.dataModel.Device,java.lang.Integer) throws java.lang.Exception at parameter at index 0
  SEVERE: Method, public javax.ws.rs.core.Response com.m.mobileautomation.devices.webServices.DevicesWebService.acquireDevice(com.m.mobileautomation.devices.dataModel.Device,java.lang.Integer) throws java.lang.Exception, annotated with POST of resource, class com.m.mobileautomation.devices.webServices.DevicesWebService, is not recognized as valid resource method.
Exception in thread "main" com.sun.jersey.spi.inject.Errors$ErrorMessagesException
    at com.sun.jersey.spi.inject.Errors.processErrorMessages(Errors.java:170)
    at com.sun.jersey.spi.inject.Errors.postProcess(Errors.java:136)
    at com.sun.jersey.spi.inject.Errors.processWithErrors(Errors.java:199)
    at com.sun.jersey.server.impl.application.WebApplicationImpl.initiate(WebApplicationImpl.java:795)
    at com.sun.jersey.api.container.ContainerFactory.createContainer(ContainerFactory.java:172)
    at com.sun.jersey.api.container.ContainerFactory.createContainer(ContainerFactory.java:264)
    at com.sun.jersey.api.container.ContainerFactory.createContainer(ContainerFactory.java:246)
    at com.sun.jersey.api.container.httpserver.HttpServerFactory.create(HttpServerFactory.java:117)
    at com.sun.jersey.api.container.httpserver.HttpServerFactory.create(HttpServerFactory.java:92)
    at com.m.mobileautomation.devices.webServices.DevicesWebService.main(DevicesWebService.java:86)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:483)
    at com.intellij.rt.execution.application.AppMain.main(AppMain.java:144)

如果我注释掉 public Response acquireDevice 一切正常。

我也尝试删除 `` 但仍然出现错误：

SEVERE: The following errors and warnings have been detected with resource and/or provider classes:
  SEVERE: Missing dependency for method public void com.m.mobileautomation.devices.webServices.DevicesWebService.acquireDevice(com.m.mobileautomation.devices.dataModel.Device,java.lang.Integer) throws java.lang.Exception at parameter at index 0
  SEVERE: Method, public void com.m.mobileautomation.devices.webServices.DevicesWebService.acquireDevice(com.m.mobileautomation.devices.dataModel.Device,java.lang.Integer) throws java.lang.Exception, annotated with POST of resource, class com.m.mobileautomation.devices.webServices.DevicesWebService, is not recognized as valid resource method.
Exception in thread "main" com.sun.jersey.spi.inject.Errors$ErrorMessagesException
    at com.sun.jersey.spi.inject.Errors.processErrorMessages(Errors.java:170)
    at com.sun.jersey.spi.inject.Errors.postProcess(Errors.java:136)
    at com.sun.jersey.spi.inject.Errors.processWithErrors(Errors.java:199)
    at com.sun.jersey.server.impl.application.WebApplicationImpl.initiate(WebApplicationImpl.java:795)
    at com.sun.jersey.api.container.ContainerFactory.createContainer(ContainerFactory.java:172)
    at com.sun.jersey.api.container.ContainerFactory.createContainer(ContainerFactory.java:264)
    at com.sun.jersey.api.container.ContainerFactory.createContainer(ContainerFactory.java:246)
    at com.sun.jersey.api.container.httpserver.HttpServerFactory.create(HttpServerFactory.java:117)
    at com.sun.jersey.api.container.httpserver.HttpServerFactory.create(HttpServerFactory.java:92)
    at com.waze.mobileautomation.devices.webServices.DevicesWebService.main(DevicesWebService.java:87)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:483)
    at com.intellij.rt.execution.application.AppMain.main(AppMain.java:144)

我该如何解决这个问题？

【问题讨论】：

阅读@PathParam 的Javadoc，它将告诉您使用自定义类型参数的要求。 Jersey 不知道如何从字符串创建 Device。但是有几种方法可以让 Jersey 知道如何创建它。请参阅 javadoc
@PathParam java 文档只处理参数命名而不是从字符串到 java 对象的转换。我已按照本教程进行操作，我缺少什么？ mkyong.com/webservices/jax-rs/…
您没有读过一些关于静态fromString(String) 或valueOf(String) 方法或接受字符串的构造函数的内容吗？这些是您的Device 类的选项，如果您想将它用作@PathParam 的参数类型。您需要从传递给这三个选项之一的字符串构造Device
我会用谷歌搜索它。基本上，如果我想使用 POST 发送“设备”，我只能在消息正文中发送它。对吗？
如果您希望它是 @PathParam，这意味着您希望将 JSON 放在 URL 中。这并不常见，而且是个坏主意。所以把它放在体内

标签： java html http jersey jackson

【解决方案1】：

正如@peeskillet 所说，@PathParam 不应该用于传递对象，因为它更常用于指定一个变量，您将使用它来标识您正在操作的资源/对象（例如，在您的情况下，我可能会使用acquireDevice/{deviceId}/{port} 如果说 id 事先有任何意义）。

像现在这样使用它还可以在您进行测试或需要查看日志中发生的情况时真正为您混淆内容 - 想想中间卡住 json 的条目在您的应用程序访问中的外观记录。

如果您要传递对象，您绝对应该使用请求的主体 - 还要注意杰克逊（我看到您标记了它，所以我假设这就是您在 Jersey 中使用的）必须知道如何反序列化该对象否则你也会失败。

【讨论】：