J2EE Jersey 文件上传 - 输入始终为空

Question

我尝试创建一个上传文件的 restful 服务。我按照以下步骤操作：

http://examples.javacodegeeks.com/enterprise-java/rest/jersey/jersey-file-upload-example/

http://www.mkyong.com/webservices/jax-rs/file-upload-example-in-jersey/

但是，当我上传文件（例如 .pdf）时，输入的 FormDataMultiPart 始终为 NULL，我不明白为什么。我使用库 "jersey-multipart" 和 "jersey-core"。我的代码：

Restful 服务：

 @Path("/reservation")
    public class ReservationWs {

        /** The Constant log. */
        private static final Logger LOGGER = LoggerFactory.getLogger(ReservationWs.class.getName());

        private static final String SERVER_UPLOAD_LOCATION_FOLDER = "C://opt/share/reservation/";

        @POST
        @Path("/upload")
        @Consumes(MediaType.MULTIPART_FORM_DATA)
        public Response uploadFile(
                @FormDataParam("file") InputStream uploadedInputStream,
                @FormDataParam("file") FormDataContentDisposition fileDetail) {

            String uploadedFileLocation = SERVER_UPLOAD_LOCATION_FOLDER
                    + fileDetail.getFileName();

            // save it
            saveFile(uploadedInputStream, uploadedFileLocation);

            String output = "File uploaded to : " + uploadedFileLocation;

            return Response.status(200).entity(output).build();

        }

        @POST
        @Path("/upload2")
        @Consumes(MediaType.MULTIPART_FORM_DATA)
        public Response uploadFile2(FormDataMultiPart form) {

             FormDataBodyPart filePart = form.getField("file");

             ContentDisposition headerOfFilePart =  filePart.getContentDisposition();

             InputStream fileInputStream = filePart.getValueAs(InputStream.class);

             String filePath = SERVER_UPLOAD_LOCATION_FOLDER + headerOfFilePart.getFileName();

            // save the file to the server
            saveFile(fileInputStream, filePath);

            String output = "File saved to server location using FormDataMultiPart : " + filePath;
            System.out.println(output);

            return Response.status(200).entity(output).build();

        }
    }

我的客户：

<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Strict//EN" "http://www.w3.org/TR/html4/strict.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
<title>Form Page</title>
</head>
<body>
<h1>Upload a File</h1>

    <form action="reservation/upload" method="post" enctype="multipart/form-data">

       <p>
        Select a file : <input type="file" name="file" size="55" />
       </p>

       <input type="submit" value="Upload It" />
    </form>

</body>
</html>

当我尝试调用 "upload" 时，输入为空并且错误记录：

GRAVE: El Servlet.service() para el servlet [rest_1288520529] en el contexto con ruta [/checking] lanzó la excepción [Error processing webservice request] con causa raíz java.lang.NullPointerException at com.checking.reservation.ws.ReservationWs.uploadFile(ReservationWs.java:74) 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:497) at org.apache.openejb.server.cxf.rs.PojoInvoker.performInvocation(PojoInvoker.java:43) at org.apache.cxf.service.invoker.AbstractInvoker.invoke(AbstractInvoker.java:96) at org.apache.cxf.jaxrs.JAXRSInvoker.invoke(JAXRSInvoker.java:165) at org.apache.cxf.jaxrs.JAXRSInvoker.invoke(JAXRSInvoker.java:89) at org.apache.openejb.server.cxf.rs.AutoJAXRSInvoker.invoke(AutoJAXRSInvoker.java:68) at org.apache.cxf.interceptor.ServiceInvokerInterceptor.run(ServiceInvokerInterceptor.java:57) at org.apache.cxf.interceptor.ServiceInvokerInterceptor.handleMessage(ServiceInvokerInterceptor.java:93) at org.apache.cxf.phase.PhaseInterceptorChain.doIntercept(PhaseInterceptorChain.java:263) at org.apache.cxf.transport.ChainInitiationObserver.onMessage(ChainInitiationObserver.java:121) at org.apache.cxf.transport.http.AbstractHTTPDestination.invoke(AbstractHTTPDestination.java:240) at org.apache.openejb.server.cxf.rs.CxfRsHttpListener.onMessage(CxfRsHttpListener.java:187) at org.apache.openejb.server.rest.RsServlet.service(RsServlet.java:53) at javax.servlet.http.HttpServlet.service(HttpServlet.java:727) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:303) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208) at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208) at net.bull.javamelody.MonitoringFilter.doFilter(MonitoringFilter.java:198) at net.bull.javamelody.MonitoringFilter.doFilter(MonitoringFilter.java:176) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208) at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:220) at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:122) at org.apache.tomee.catalina.OpenEJBValve.invoke(OpenEJBValve.java:44) at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:501) at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:171) at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:103) at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:950) at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:116) at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:408) at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1070) at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:611) at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:316) at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142) at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617) at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61) at java.lang.Thread.run(Thread.java:745)

当我尝试调用 "upload2" 时，输入为空并且错误记录：

sep 11, 2015 9:12:21 AM org.apache.catalina.core.StandardWrapperValve invoke GRAVE: El Servlet.service() para el servlet [rest_348842263] en el contexto con ruta [/checking] lanzó la excepción [Error processing webservice request] con causa raíz java.lang.NullPointerException at com.checking.reservation.ws.ReservationWs.uploadFile2(ReservationWs.java:90) 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:497) at org.apache.openejb.server.cxf.rs.PojoInvoker.performInvocation(PojoInvoker.java:43) at org.apache.cxf.service.invoker.AbstractInvoker.invoke(AbstractInvoker.java:96) at org.apache.cxf.jaxrs.JAXRSInvoker.invoke(JAXRSInvoker.java:165) at org.apache.cxf.jaxrs.JAXRSInvoker.invoke(JAXRSInvoker.java:89) at org.apache.openejb.server.cxf.rs.AutoJAXRSInvoker.invoke(AutoJAXRSInvoker.java:68) at org.apache.cxf.interceptor.ServiceInvokerInterceptor.run(ServiceInvokerInterceptor.java:57) at org.apache.cxf.interceptor.ServiceInvokerInterceptor.handleMessage(ServiceInvokerInterceptor.java:93) at org.apache.cxf.phase.PhaseInterceptorChain.doIntercept(PhaseInterceptorChain.java:263) at org.apache.cxf.transport.ChainInitiationObserver.onMessage(ChainInitiationObserver.java:121) at org.apache.cxf.transport.http.AbstractHTTPDestination.invoke(AbstractHTTPDestination.java:240) at org.apache.openejb.server.cxf.rs.CxfRsHttpListener.onMessage(CxfRsHttpListener.java:187) at org.apache.openejb.server.rest.RsServlet.service(RsServlet.java:53) at javax.servlet.http.HttpServlet.service(HttpServlet.java:727) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:303) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208) at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208) at net.bull.javamelody.MonitoringFilter.doFilter(MonitoringFilter.java:198) at net.bull.javamelody.MonitoringFilter.doFilter(MonitoringFilter.java:176) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208) at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:220) at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:122) at org.apache.tomee.catalina.OpenEJBValve.invoke(OpenEJBValve.java:44) at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:501) at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:171) at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:103) at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:950) at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:116) at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:408) at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1070) at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:611) at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:316) at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142) at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617) at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61) at java.lang.Thread.run(Thread.java:745)

有什么想法吗？

Answer 1

我暂时找到了一个不好的解决方案。

@POST
@Path("/upload")
@Consumes(MediaType.MULTIPART_FORM_DATA)
public Response uploadFile(@FormDataParam("file") InputStream file, @FormDataParam("file") FormDataContentDisposition fileDetail, @QueryParam("fileName") String fileName){
    ...
    ...
    String uploadedFileLocation = SERVER_UPLOAD_LOCATION_FOLDER+ fileName;//fileDetail.getFileName();

    // save it
    saveFile(file, uploadedFileLocation);
    ...

    //Logic of the service.
    ...

    //Delete file from local.
}

private void saveFile(InputStream uploadedInputStream, String serverLocation) throws IOException {

    OutputStream outpuStream=null;
    try {
            outpuStream = new FileOutputStream(new File(serverLocation));
            int read = 0;
            byte[] bytes = new byte[1024];
            outpuStream = new FileOutputStream(new File(serverLocation));
            while ((read = uploadedInputStream.read(bytes)) != -1) {
                outpuStream.write(bytes, 0, read);
            }
            outpuStream.flush();
            outpuStream.close();

    } catch( IOException e){
        LOGGER.debug("[UploadWs - saveFile] - error: "+e);
    } finally{
        if(outpuStream!=null){
            outpuStream.close();
        }
    }
}

"fileDetail" 始终为空，我不知道为什么（如果有人知道解决方案，请说出来）所以我添加了客户端发送的参数 "fileName"（文件名）我。我构建位置，将文件保存在本地，执行服务逻辑（在我的例子中，我发送一封包含此文件的电子邮件），然后从本地删除文件。

这不是一个好的解决方案，因为我添加了一个不必要的参数并将文件保存在本地。

J2EE Jersey 文件上传 - 输入始终为空

J2EE Jersey File Upload - input is always null

java

upload

multipart

jersey

jakarta-ee