Question

我正在使用SpringBoot REST，我有一个像下面这样的控制器。

@PostMapping()
public MainBanner createMainBanner(@ModelAttribute MainBanner mainBanner, @RequestParam("img") MultipartFile img) {
    String sourceFileName = img.getOriginalFilename();
    String sourceFileNameExtension = FilenameUtils.getExtension(sourceFileName).toLowerCase();

    String destinationFileName;
    File destinationFile;

    do {
        destinationFileName = RandomStringUtils.randomAlphanumeric(32) + "." + sourceFileNameExtension;
        destinationFile = new File(ServerConfig.MAIN_BANNER_IMAGE_URL + destinationFileName);
    } while (destinationFile.exists());

    destinationFile.getParentFile().mkdirs();
    try {
        img.transferTo(destinationFile);
    } catch (IllegalStateException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    } catch (IOException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    }

    mainBanner.setImg(destinationFileName);

    return mainBannerService.createMainBanner(mainBanner);
}

当我使用Postman测试时，它会抛出FileNotFoundException。这是日志。

java.io.FileNotFoundException: /private/var/folders/zz/zyxvpxvq6csfxvn_n0000000000000/T/tomcat.2846331348458787719.8080/work/Tomcat/localhost/ROOT/upload_310ffd48_c0d8_442e_8cd1_4fc7623803cb_00000003.tmp (No such file or directory)
at java.io.FileInputStream.open0(Native Method) ~[na:1.8.0_73]
at java.io.FileInputStream.open(FileInputStream.java:195) ~[na:1.8.0_73]
at java.io.FileInputStream.<init>(FileInputStream.java:138) ~[na:1.8.0_73]
at org.apache.tomcat.util.http.fileupload.disk.DiskFileItem.getInputStream(DiskFileItem.java:188) ~[tomcat-embed-core-8.5.6.jar!/:8.5.6]
at org.apache.catalina.core.ApplicationPart.getInputStream(ApplicationPart.java:100) ~[tomcat-embed-core-8.5.6.jar!/:8.5.6]
at org.springframework.web.multipart.support.StandardMultipartHttpServletRequest$StandardMultipartFile.getBytes(StandardMultipartHttpServletRequest.java:291) ~[spring-web-4.3.4.RELEASE.jar!/:4.3.4.RELEASE]
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:1.8.0_73]
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[na:1.8.0_73]
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:1.8.0_73]
at java.lang.reflect.Method.invoke(Method.java:497) ~[na:1.8.0_73]
at com.fasterxml.jackson.databind.ser.BeanPropertyWriter.serializeAsField(BeanPropertyWriter.java:664) ~[jackson-databind-2.8.4.jar!/:2.8.4]
at com.fasterxml.jackson.databind.ser.std.BeanSerializerBase.serializeFields(BeanSerializerBase.java:690) ~[jackson-databind-2.8.4.jar!/:2.8.4]
at com.fasterxml.jackson.databind.ser.BeanSerializer.serialize(BeanSerializer.java:155) ~[jackson-databind-2.8.4.jar!/:2.8.4]
at com.fasterxml.jackson.databind.ser.BeanPropertyWriter.serializeAsField(BeanPropertyWriter.java:704) ~[jackson-databind-2.8.4.jar!/:2.8.4]
at com.fasterxml.jackson.databind.ser.std.BeanSerializerBase.serializeFields(BeanSerializerBase.java:690) ~[jackson-databind-2.8.4.jar!/:2.8.4]
at com.fasterxml.jackson.databind.ser.BeanSerializer.serialize(BeanSerializer.java:155) ~[jackson-databind-2.8.4.jar!/:2.8.4]
at com.fasterxml.jackson.databind.ser.std.CollectionSerializer.serializeContents(CollectionSerializer.java:149) ~[jackson-databind-2.8.4.jar!/:2.8.4]
at com.fasterxml.jackson.databind.ser.std.CollectionSerializer.serialize(CollectionSerializer.java:112) ~[jackson-databind-2.8.4.jar!/:2.8.4]
at com.fasterxml.jackson.databind.ser.std.CollectionSerializer.serialize(CollectionSerializer.java:25) ~[jackson-databind-2.8.4.jar!/:2.8.4]
at com.fasterxml.jackson.databind.ser.std.MapSerializer.serializeFields(MapSerializer.java:633) ~[jackson-databind-2.8.4.jar!/:2.8.4]
at com.fasterxml.jackson.databind.ser.std.MapSerializer.serialize(MapSerializer.java:536) ~[jackson-databind-2.8.4.jar!/:2.8.4]
at com.fasterxml.jackson.databind.ser.std.MapSerializer.serialize(MapSerializer.java:30) ~[jackson-databind-2.8.4.jar!/:2.8.4]
at com.fasterxml.jackson.databind.ser.DefaultSerializerProvider.serializeValue(DefaultSerializerProvider.java:416) ~[jackson-databind-2.8.4.jar!/:2.8.4]
at com.fasterxml.jackson.databind.ObjectWriter$Prefetch.serialize(ObjectWriter.java:1416) ~[jackson-databind-2.8.4.jar!/:2.8.4]
at com.fasterxml.jackson.databind.ObjectWriter.writeValue(ObjectWriter.java:940) ~[jackson-databind-2.8.4.jar!/:2.8.4]
at org.springframework.http.converter.json.AbstractJackson2HttpMessageConverter.writeInternal(AbstractJackson2HttpMessageConverter.java:267) ~[spring-web-4.3.4.RELEASE.jar!/:4.3.4.RELEASE]
at org.springframework.http.converter.AbstractGenericHttpMessageConverter.write(AbstractGenericHttpMessageConverter.java:100) ~[spring-web-4.3.4.RELEASE.jar!/:4.3.4.RELEASE]
at org.springframework.web.servlet.mvc.method.annotation.AbstractMessageConverterMethodProcessor.writeWithMessageConverters(AbstractMessageConverterMethodProcessor.java:232) ~[spring-webmvc-4.3.4.RELEASE.jar!/:4.3.4.RELEASE]
at org.springframework.web.servlet.mvc.method.annotation.HttpEntityMethodProcessor.handleReturnValue(HttpEntityMethodProcessor.java:203) ~[spring-webmvc-4.3.4.RELEASE.jar!/:4.3.4.RELEASE]
at org.springframework.web.method.support.HandlerMethodReturnValueHandlerComposite.handleReturnValue(HandlerMethodReturnValueHandlerComposite.java:81) ~[spring-web-4.3.4.RELEASE.jar!/:4.3.4.RELEASE]
at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:132) ~[spring-webmvc-4.3.4.RELEASE.jar!/:4.3.4.RELEASE]
at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:827) ~[spring-webmvc-4.3.4.RELEASE.jar!/:4.3.4.RELEASE]
at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:738) ~[spring-webmvc-4.3.4.RELEASE.jar!/:4.3.4.RELEASE]
at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:85) ~[spring-webmvc-4.3.4.RELEASE.jar!/:4.3.4.RELEASE]
at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:963) ~[spring-webmvc-4.3.4.RELEASE.jar!/:4.3.4.RELEASE]
at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:897) ~[spring-webmvc-4.3.4.RELEASE.jar!/:4.3.4.RELEASE]
at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:970) ~[spring-webmvc-4.3.4.RELEASE.jar!/:4.3.4.RELEASE]
at org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:872) ~[spring-webmvc-4.3.4.RELEASE.jar!/:4.3.4.RELEASE]
at javax.servlet.http.HttpServlet.service(HttpServlet.java:648) ~[tomcat-embed-core-8.5.6.jar!/:8.5.6]
at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:846) ~[spring-webmvc-4.3.4.RELEASE.jar!/:4.3.4.RELEASE]
at javax.servlet.http.HttpServlet.service(HttpServlet.java:729) ~[tomcat-embed-core-8.5.6.jar!/:8.5.6]
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:230) ~[tomcat-embed-core-8.5.6.jar!/:8.5.6]
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:165) ~[tomcat-embed-core-8.5.6.jar!/:8.5.6]
at org.apache.catalina.core.ApplicationDispatcher.invoke(ApplicationDispatcher.java:726) [tomcat-embed-core-8.5.6.jar!/:8.5.6]
at org.apache.catalina.core.ApplicationDispatcher.processRequest(ApplicationDispatcher.java:471) [tomcat-embed-core-8.5.6.jar!/:8.5.6]
at org.apache.catalina.core.ApplicationDispatcher.doForward(ApplicationDispatcher.java:394) [tomcat-embed-core-8.5.6.jar!/:8.5.6]
at org.apache.catalina.core.ApplicationDispatcher.forward(ApplicationDispatcher.java:311) [tomcat-embed-core-8.5.6.jar!/:8.5.6]
at org.apache.catalina.core.StandardHostValve.custom(StandardHostValve.java:395) [tomcat-embed-core-8.5.6.jar!/:8.5.6]
at org.apache.catalina.core.StandardHostValve.status(StandardHostValve.java:254) [tomcat-embed-core-8.5.6.jar!/:8.5.6]
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:177) [tomcat-embed-core-8.5.6.jar!/:8.5.6]
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:79) [tomcat-embed-core-8.5.6.jar!/:8.5.6]
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:87) [tomcat-embed-core-8.5.6.jar!/:8.5.6]
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:349) [tomcat-embed-core-8.5.6.jar!/:8.5.6]
at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:784) [tomcat-embed-core-8.5.6.jar!/:8.5.6]
at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:66) [tomcat-embed-core-8.5.6.jar!/:8.5.6]
at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:802) [tomcat-embed-core-8.5.6.jar!/:8.5.6]
at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1410) [tomcat-embed-core-8.5.6.jar!/:8.5.6]
at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49) [tomcat-embed-core-8.5.6.jar!/:8.5.6]
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142) [na:1.8.0_73]
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617) [na:1.8.0_73]
at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61) [tomcat-embed-core-8.5.6.jar!/:8.5.6]
at java.lang.Thread.run(Thread.java:745) [na:1.8.0_73]

我想createMainBanner方法的主体不会运行。如果我在主体的第一行放置打印日志代码，则控制台上没有日志。问题是什么？

Answer 1

我对这个逻辑实际上要做的事情感到有点困惑

do {
    destinationFileName = RandomStringUtils.randomAlphanumeric(32) + "." + sourceFileNameExtension;
    destinationFile = new File(ServerConfig.MAIN_BANNER_IMAGE_URL + destinationFileName);
} while (destinationFile.exists());

首先，destinationFile不存在，因为你从未创建它（调用new File()将不会创建文件。其次，如果你在这个循环中创建文件，它将评估为true，你会继续创建文件......也就是说，直到你耗尽文件系统。

您似乎只想创建一个文件，可以使用https://docs.oracle.com/javase/7/docs/api/java/io/File.html#createNewFile()。

在SpringBoot REST API中发布时的FileNotFoundException

1 个答案: