我有FtpRemoteFileTemplate：
@Autowired
private FtpRemoteFileTemplate ftpTemplate;
我以这种方式使用它：
if (ftpTemplate.exists(fileAbsPath)) {
return getRemoteFileAsByteArray(fileAbsPath);
}
其中getRemoteFileAsByteArray是
private byte[] getRemoteFileAsByteArray(String absoluteFileName) {
return ftpTemplate.execute(session -> IOUtils.toByteArray(session.readRaw(absoluteFileName)));
}
语句ftpTemplate.exists(fileAbsPath)正常并且正确返回true，ftpTemplate.execute(session -> IOUtils.toByteArray(session.readRaw(absoluteFileName)))一段时间后抛出此异常：
org.springframework.messaging.MessagingException: Failed to execute on session; nested exception is java.io.IOException: Failed to obtain InputStream for remote file /xxx/xxx/foo.jpg: 425
at org.springframework.integration.file.remote.RemoteFileTemplate.execute(RemoteFileTemplate.java:419) ~[spring-integration-file-4.2.4.RELEASE.jar:?]
at xxx.xxx.service.impl.ImageServiceFtpImpl.getRemoteFileAsByteArray(ImageServiceFtpImpl.java:91) ~[classes/:?]
at xxx.xxx.service.impl.ImageServiceFtpImpl.getImage(ImageServiceFtpImpl.java:64) [classes/:?]
at xxx.xxx.service.impl.AbstractImageService.getOriginalTransitImage(AbstractImageService.java:22) [classes/:?]
at xxx.xxx.service.rest.ServiceController.getOriginalTransitImage(ServiceController.java:138) [classes/:?]
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[?:1.8.0_71]
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[?:1.8.0_71]
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[?:1.8.0_71]
at java.lang.reflect.Method.invoke(Method.java:497) ~[?:1.8.0_71]
at org.springframework.web.method.support.InvocableHandlerMethod.doInvoke(InvocableHandlerMethod.java:222) [spring-web-4.2.4.RELEASE.jar:4.2.4.RELEASE]
at org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:137) [spring-web-4.2.4.RELEASE.jar:4.2.4.RELEASE]
at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:110) [spring-webmvc-4.2.4.RELEASE.jar:4.2.4.RELEASE]
at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:814) [spring-webmvc-4.2.4.RELEASE.jar:4.2.4.RELEASE]
at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:737) [spring-webmvc-4.2.4.RELEASE.jar:4.2.4.RELEASE]
at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:85) [spring-webmvc-4.2.4.RELEASE.jar:4.2.4.RELEASE]
at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:959) [spring-webmvc-4.2.4.RELEASE.jar:4.2.4.RELEASE]
at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:893) [spring-webmvc-4.2.4.RELEASE.jar:4.2.4.RELEASE]
at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:969) [spring-webmvc-4.2.4.RELEASE.jar:4.2.4.RELEASE]
at org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:860) [spring-webmvc-4.2.4.RELEASE.jar:4.2.4.RELEASE]
at javax.servlet.http.HttpServlet.service(HttpServlet.java:687) [javax.servlet-api-3.1.0.jar:3.1.0]
at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:845) [spring-webmvc-4.2.4.RELEASE.jar:4.2.4.RELEASE]
at javax.servlet.http.HttpServlet.service(HttpServlet.java:790) [javax.servlet-api-3.1.0.jar:3.1.0]
at org.eclipse.jetty.servlet.ServletHolder.handle(ServletHolder.java:812) [jetty-servlet-9.2.14.v20151106.jar:9.2.14.v20151106]
at org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1669) [jetty-servlet-9.2.14.v20151106.jar:9.2.14.v20151106]
at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:316) [spring-security-web-4.0.3.RELEASE.jar:4.0.3.RELEASE]
at org.springframework.security.web.access.intercept.FilterSecurityInterceptor.invoke(FilterSecurityInterceptor.java:126) [spring-security-web-4.0.3.RELEASE.jar:4.0.3.RELEASE]
at org.springframework.security.web.access.intercept.FilterSecurityInterceptor.doFilter(FilterSecurityInterceptor.java:90) [spring-security-web-4.0.3.RELEASE.jar:4.0.3.RELEASE]
at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:330) [spring-security-web-4.0.3.RELEASE.jar:4.0.3.RELEASE]
at org.springframework.security.web.access.ExceptionTranslationFilter.doFilter(ExceptionTranslationFilter.java:114) [spring-security-web-4.0.3.RELEASE.jar:4.0.3.RELEASE]
at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:330) [spring-security-web-4.0.3.RELEASE.jar:4.0.3.RELEASE]
at org.springframework.security.web.session.SessionManagementFilter.doFilter(SessionManagementFilter.java:122) [spring-security-web-4.0.3.RELEASE.jar:4.0.3.RELEASE]
at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:330) [spring-security-web-4.0.3.RELEASE.jar:4.0.3.RELEASE]
at org.springframework.security.web.authentication.AnonymousAuthenticationFilter.doFilter(AnonymousAuthenticationFilter.java:111) [spring-security-web-4.0.3.RELEASE.jar:4.0.3.RELEASE]
at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:330) [spring-security-web-4.0.3.RELEASE.jar:4.0.3.RELEASE]
at org.springframework.security.web.servletapi.SecurityContextHolderAwareRequestFilter.doFilter(SecurityContextHolderAwareRequestFilter.java:169) [spring-security-web-4.0.3.RELEASE.jar:4.0.3.RELEASE]
at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:330) [spring-security-web-4.0.3.RELEASE.jar:4.0.3.RELEASE]
at org.springframework.security.web.savedrequest.RequestCacheAwareFilter.doFilter(RequestCacheAwareFilter.java:48) [spring-security-web-4.0.3.RELEASE.jar:4.0.3.RELEASE]
at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:330) [spring-security-web-4.0.3.RELEASE.jar:4.0.3.RELEASE]
at org.springframework.security.web.authentication.www.BasicAuthenticationFilter.doFilterInternal(BasicAuthenticationFilter.java:158) [spring-security-web-4.0.3.RELEASE.jar:4.0.3.RELEASE]
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) [spring-web-4.2.4.RELEASE.jar:4.2.4.RELEASE]
at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:330) [spring-security-web-4.0.3.RELEASE.jar:4.0.3.RELEASE]
at org.springframework.security.web.authentication.logout.LogoutFilter.doFilter(LogoutFilter.java:120) [spring-security-web-4.0.3.RELEASE.jar:4.0.3.RELEASE]
at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:330) [spring-security-web-4.0.3.RELEASE.jar:4.0.3.RELEASE]
at org.springframework.security.web.header.HeaderWriterFilter.doFilterInternal(HeaderWriterFilter.java:64) [spring-security-web-4.0.3.RELEASE.jar:4.0.3.RELEASE]
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) [spring-web-4.2.4.RELEASE.jar:4.2.4.RELEASE]
at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:330) [spring-security-web-4.0.3.RELEASE.jar:4.0.3.RELEASE]
at org.springframework.security.web.context.SecurityContextPersistenceFilter.doFilter(SecurityContextPersistenceFilter.java:91) [spring-security-web-4.0.3.RELEASE.jar:4.0.3.RELEASE]
at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:330) [spring-security-web-4.0.3.RELEASE.jar:4.0.3.RELEASE]
at org.springframework.security.web.context.request.async.WebAsyncManagerIntegrationFilter.doFilterInternal(WebAsyncManagerIntegrationFilter.java:53) [spring-security-web-4.0.3.RELEASE.jar:4.0.3.RELEASE]
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) [spring-web-4.2.4.RELEASE.jar:4.2.4.RELEASE]
at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:330) [spring-security-web-4.0.3.RELEASE.jar:4.0.3.RELEASE]
at xxx.xxx.service.util.SimpleCORSFilter.doFilter(SimpleCORSFilter.java:26) [classes/:?]
at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:330) [spring-security-web-4.0.3.RELEASE.jar:4.0.3.RELEASE]
at org.springframework.security.web.FilterChainProxy.doFilterInternal(FilterChainProxy.java:213) [spring-security-web-4.0.3.RELEASE.jar:4.0.3.RELEASE]
at org.springframework.security.web.FilterChainProxy.doFilter(FilterChainProxy.java:176) [spring-security-web-4.0.3.RELEASE.jar:4.0.3.RELEASE]
at org.springframework.web.filter.DelegatingFilterProxy.invokeDelegate(DelegatingFilterProxy.java:346) [spring-web-4.2.4.RELEASE.jar:4.2.4.RELEASE]
at org.springframework.web.filter.DelegatingFilterProxy.doFilter(DelegatingFilterProxy.java:262) [spring-web-4.2.4.RELEASE.jar:4.2.4.RELEASE]
at org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1652) [jetty-servlet-9.2.14.v20151106.jar:9.2.14.v20151106]
at org.eclipse.jetty.servlet.ServletHandler.doHandle(ServletHandler.java:585) [jetty-servlet-9.2.14.v20151106.jar:9.2.14.v20151106]
at org.eclipse.jetty.server.handler.ScopedHandler.handle(ScopedHandler.java:143) [jetty-server-9.2.14.v20151106.jar:9.2.14.v20151106]
at org.eclipse.jetty.security.SecurityHandler.handle(SecurityHandler.java:577) [jetty-security-9.2.14.v20151106.jar:9.2.14.v20151106]
at org.eclipse.jetty.server.session.SessionHandler.doHandle(SessionHandler.java:223) [jetty-server-9.2.14.v20151106.jar:9.2.14.v20151106]
at org.eclipse.jetty.server.handler.ContextHandler.doHandle(ContextHandler.java:1127) [jetty-server-9.2.14.v20151106.jar:9.2.14.v20151106]
at org.eclipse.jetty.servlet.ServletHandler.doScope(ServletHandler.java:515) [jetty-servlet-9.2.14.v20151106.jar:9.2.14.v20151106]
at org.eclipse.jetty.server.session.SessionHandler.doScope(SessionHandler.java:185) [jetty-server-9.2.14.v20151106.jar:9.2.14.v20151106]
at org.eclipse.jetty.server.handler.ContextHandler.doScope(ContextHandler.java:1061) [jetty-server-9.2.14.v20151106.jar:9.2.14.v20151106]
at org.eclipse.jetty.server.handler.ScopedHandler.handle(ScopedHandler.java:141) [jetty-server-9.2.14.v20151106.jar:9.2.14.v20151106]
at org.eclipse.jetty.server.handler.ContextHandlerCollection.handle(ContextHandlerCollection.java:215) [jetty-server-9.2.14.v20151106.jar:9.2.14.v20151106]
at org.eclipse.jetty.server.handler.HandlerCollection.handle(HandlerCollection.java:110) [jetty-server-9.2.14.v20151106.jar:9.2.14.v20151106]
at org.eclipse.jetty.server.handler.HandlerWrapper.handle(HandlerWrapper.java:97) [jetty-server-9.2.14.v20151106.jar:9.2.14.v20151106]
at org.eclipse.jetty.server.Server.handle(Server.java:499) [jetty-server-9.2.14.v20151106.jar:9.2.14.v20151106]
at org.eclipse.jetty.server.HttpChannel.handle(HttpChannel.java:311) [jetty-server-9.2.14.v20151106.jar:9.2.14.v20151106]
at org.eclipse.jetty.server.HttpConnection.onFillable(HttpConnection.java:257) [jetty-server-9.2.14.v20151106.jar:9.2.14.v20151106]
at org.eclipse.jetty.io.AbstractConnection$2.run(AbstractConnection.java:544) [jetty-io-9.2.14.v20151106.jar:9.2.14.v20151106]
at org.eclipse.jetty.util.thread.QueuedThreadPool.runJob(QueuedThreadPool.java:635) [jetty-util-9.2.14.v20151106.jar:9.2.14.v20151106]
at org.eclipse.jetty.util.thread.QueuedThreadPool$3.run(QueuedThreadPool.java:555) [jetty-util-9.2.14.v20151106.jar:9.2.14.v20151106]
at java.lang.Thread.run(Thread.java:745) [?:1.8.0_71]
Caused by: java.io.IOException: Failed to obtain InputStream for remote file /xxx/xxx/foo.jpg: 425
at org.springframework.integration.ftp.session.FtpSession.readRaw(FtpSession.java:96) ~[spring-integration-ftp-4.2.4.RELEASE.jar:?]
at xxx.xxx.service.impl.ImageServiceFtpImpl.lambda$0(ImageServiceFtpImpl.java:91) ~[classes/:?]
at org.springframework.integration.file.remote.RemoteFileTemplate.execute(RemoteFileTemplate.java:410) ~[spring-integration-file-4.2.4.RELEASE.jar:?]
... 76 more
从FileZilla我可以从同一台计算机上检索同一个文件。
我哪里出错？
答案 0 :(得分：2)
FTP需要两个独立的通道进行通信。 command channel正在为您工作，因为您可以从服务器获取文件存在状态。如果您正在尝试以活动模式进行通信，则需要服务器启动与系统的连接，在这种情况下，防火墙可能会阻止此类连接，从而导致IO异常。
要解决此问题，您可以将客户端模式更改为Passive。在config中，将clientMode更改为2.或者，如果您拥有FTPClient实例，则还可以使用client.enterLocalPassiveMode();。
PASSIVE_LOCAL_DATA_CONNECTION_MODE = 2