在Windows上运行的好好的，打jar包上传到linux服务器就报错

各位大佬，帮忙看一下！！
我通过这个方法把图片上传到服务器，可以正常存储，查看了一下存储后的图片所占内存也没错，但是访问时就报500错误；
public String uplodeFile(MultipartFile file) {
        String fileName=file.getOriginalFilename();
        String fileSuffix=fileName.substring(fileName.lastIndexOf("."));        try{
            String rootPath = mImagespath;            /*文件路径不存在则要创建文件路径*/
            File filePath=new File(rootPath);
            /*System.out.println(rootPath);
            System.out.println(request.getContextPath());*/            if (!filePath.exists()){
                filePath.mkdirs();
            }
            //最终文件名
            String newFileName=usersDao.getTimestamp()+fileSuffix;
            File realFile=new File(rootPath+File.separator+newFileName);
            FileUtils.copyInputStreamToFile(file.getInputStream(),realFile);            return newFileName;
        } catch (Exception e) {
            e.printStackTrace();
            return null;
        } }
在Windows上可以正常上传以及访问，但是项目打成jar包之后上传到Linux服务器后，就出现下面的错误；
上传成功的图片，访问时出错，报错信息如下：2019-09-06 18:02:36.132 ERROR 15899 --- [nio-8080-exec-1] o.a.c.c.C.[.[.[/].[dispatcherServlet]    : Servlet.service() for servlet [dispatcherServlet] in context with path [] threw exceptionjava.net.UnknownHostException: resources
        at java.net.AbstractPlainSocketImpl.connect(AbstractPlainSocketImpl.java:184) ~[na:1.8.0_212]
        at java.net.Socket.connect(Socket.java:589) ~[na:1.8.0_212]
        at sun.net.ftp.impl.FtpClient.doConnect(FtpClient.java:962) ~[na:1.8.0_212]
        at sun.net.ftp.impl.FtpClient.tryConnect(FtpClient.java:924) ~[na:1.8.0_212]
        at sun.net.ftp.impl.FtpClient.connect(FtpClient.java:1019) ~[na:1.8.0_212]
        at sun.net.ftp.impl.FtpClient.connect(FtpClient.java:1005) ~[na:1.8.0_212]
        at sun.net.www.protocol.ftp.FtpURLConnection.connect(FtpURLConnection.java:294) ~[na:1.8.0_212]
        at sun.net.www.protocol.ftp.FtpURLConnection.getInputStream(FtpURLConnection.java:400) ~[na:1.8.0_212]
        at org.springframework.core.io.UrlResource.getInputStream(UrlResource.java:173) ~[spring-core-5.1.8.RELEASE.jar!/:5.1.8.RELEASE]
        at org.springframework.http.converter.ResourceHttpMessageConverter.writeContent(ResourceHttpMessageConverter.java:130) ~[spring-web-5.1.8.RELEASE.jar!/:5.1.8.RELEASE]
        at org.springframework.http.converter.ResourceHttpMessageConverter.writeInternal(ResourceHttpMessageConverter.java:124) ~[spring-web-5.1.8.RELEASE.jar!/:5.1.8.RELEASE]
        at org.springframework.http.converter.ResourceHttpMessageConverter.writeInternal(ResourceHttpMessageConverter.java:45) ~[spring-web-5.1.8.RELEASE.jar!/:5.1.8.RELEASE]
        at org.springframework.http.converter.AbstractHttpMessageConverter.write(AbstractHttpMessageConverter.java:227) ~[spring-web-5.1.8.RELEASE.jar!/:5.1.8.RELEASE]
        at org.springframework.web.servlet.resource.ResourceHttpRequestHandler.handleRequest(ResourceHttpRequestHandler.java:488) ~[spring-webmvc-5.1.8.RELEASE.jar!/:5.1.8.RELEASE]
        at org.springframework.web.servlet.mvc.HttpRequestHandlerAdapter.handle(HttpRequestHandlerAdapter.java:53) ~[spring-webmvc-5.1.8.RELEASE.jar!/:5.1.8.RELEASE]
        at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:1039) ~[spring-webmvc-5.1.8.RELEASE.jar!/:5.1.8.RELEASE]
        at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:942) ~[spring-webmvc-5.1.8.RELEASE.jar!/:5.1.8.RELEASE]
        at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:1005) ~[spring-webmvc-5.1.8.RELEASE.jar!/:5.1.8.RELEASE]
        at org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:897) ~[spring-webmvc-5.1.8.RELEASE.jar!/:5.1.8.RELEASE]
        at javax.servlet.http.HttpServlet.service(HttpServlet.java:634) ~[tomcat-embed-core-9.0.21.jar!/:9.0.21]
        at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:882) ~[spring-webmvc-5.1.8.RELEASE.jar!/:5.1.8.RELEASE]
        at javax.servlet.http.HttpServlet.service(HttpServlet.java:741) ~[tomcat-embed-core-9.0.21.jar!/:9.0.21]
        at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:231) ~[tomcat-embed-core-9.0.21.jar!/:9.0.21]
        at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-9.0.21.jar!/:9.0.21]
        at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:53) ~[tomcat-embed-websocket-9.0.21.jar!/:9.0.21]
        at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-9.0.21.jar!/:9.0.21]
        at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-9.0.21.jar!/:9.0.21]
        at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:200) ~[spring-web-5.1.8.RELEASE.jar!/:5.1.8.RELEASE]
        at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:109) ~[spring-web-5.1.8.RELEASE.jar!/:5.1.8.RELEASE]
        at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-9.0.21.jar!/:9.0.21]
        at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-9.0.21.jar!/:9.0.21]
        at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:202) ~[tomcat-embed-core-9.0.21.jar!/:9.0.21]
        at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:96) [tomcat-embed-core-9.0.21.jar!/:9.0.21]
        at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:490) [tomcat-embed-core-9.0.21.jar!/:9.0.21]
        at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:139) [tomcat-embed-core-9.0.21.jar!/:9.0.21]
        at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:92) [tomcat-embed-core-9.0.21.jar!/:9.0.21]
        at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:74) [tomcat-embed-core-9.0.21.jar!/:9.0.21]
        at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:343) [tomcat-embed-core-9.0.21.jar!/:9.0.21]
        at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:408) [tomcat-embed-core-9.0.21.jar!/:9.0.21]
        at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:66) [tomcat-embed-core-9.0.21.jar!/:9.0.21]
        at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:853) [tomcat-embed-core-9.0.21.jar!/:9.0.21]
        at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1587) [tomcat-embed-core-9.0.21.jar!/:9.0.21]
        at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49) [tomcat-embed-core-9.0.21.jar!/:9.0.21]
        at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149) [na:1.8.0_212]
        at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624) [na:1.8.0_212]
        at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61) [tomcat-embed-core-9.0.21.jar!/:9.0.21]
        at java.lang.Thread.run(Thread.java:748) [na:1.8.0_212]