上传文件衫

Question

我正在尝试使用rest webservice上传文件。这是我的代码：

@POST
@Path(value="upload")
    @Consumes(MediaType.MULTIPART_FORM_DATA)
    public Response uploadFile(
    @FormDataParam("file") InputStream fileInputStream,@FormDataParam("file") FormDataContentDisposition fileDetail) {
    String filePath = "C://Users/Marya/Desktop/" +fileDetail.getFileName() ;//line 28
    System.out.println("*****serverpath********");
    saveFile(fileInputStream, filePath);
    String output = "File saved to  server location : " + filePath;
    System.out.println("done");
return Response.status(200).entity(output).build();
}

我添加了必需的罐子，我收到了这个错误

新错误

 Grave: The RuntimeException could not be mapped to a response, re-throwing to the HTTP container
    java.lang.NullPointerException
at com.example.upload.uploadFile(upload.java:28)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at com.sun.jersey.spi.container.JavaMethodInvokerFactory$1.invoke(JavaMethodInvokerFactory.java:60)
at com.sun.jersey.server.impl.model.method.dispatch.AbstractResourceMethodDispatchProvider$ResponseOutInvoker._dispatch(AbstractResourceMethodDispatchProvider.java:205)
at com.sun.jersey.server.impl.model.method.dispatch.ResourceJavaMethodDispatcher.dispatch(ResourceJavaMethodDispatcher.java:75)
at com.sun.jersey.server.impl.uri.rules.HttpMethodRule.accept(HttpMethodRule.java:302)
at com.sun.jersey.server.impl.uri.rules.RightHandPathRule.accept(RightHandPathRule.java:147)
at com.sun.jersey.server.impl.uri.rules.ResourceClassRule.accept(ResourceClassRule.java:108)
at com.sun.jersey.server.impl.uri.rules.RightHandPathRule.accept(RightHandPathRule.java:147)