Spring boot临时文件目录报错

错误信息

2018-03-05 at 15:12:03 CST ERROR org.apache.juli.logging.DirectJDKLog 181 log - Servlet.service() for servlet [dispatcherServlet] in context with path [] threw exception [Request processing failed; nested exception is org.springframework.web.multipart.MultipartException: Could not parse multipart servlet request; nested exception is java.io.IOException: The temporary upload location [/tmp/tomcat.5697655521198317313.8080/work/Tomcat/localhost/ROOT] is not valid] with root cause java.io.IOException: The temporary upload location [/tmp/tomcat.5697655521198317313.8080/work/Tomcat/localhost/ROOT] is not valid
    at org.apache.catalina.connector.Request.parseParts(Request.java:2846) ~[tomcat-embed-core-8.5.16.jar!/:8.5.16]
    at org.apache.catalina.connector.Request.parseParameters(Request.java:3215) ~[tomcat-embed-core-8.5.16.jar!/:8.5.16]
    at org.apache.catalina.connector.Request.getParameter(Request.java:1145) ~[tomcat-embed-core-8.5.16.jar!/:8.5.16]
    at org.apache.catalina.connector.RequestFacade.getParameter(RequestFacade.java:381) ~[tomcat-embed-core-8.5.16.jar!/:8.5.16]
    at org.springframework.web.filter.HiddenHttpMethodFilter.doFilterInternal(HiddenHttpMethodFilter.java:75) ~[spring-web-4.3.10.RELEASE.jar!/:4.3.10.RELEASE]
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) ~[spring-web-4.3.10.RELEASE.jar!/:4.3.10.RELEASE]
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-8.5.16.jar!/:8.5.16]
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-8.5.16.jar!/:8.5.16]
    at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:197) ~[spring-web-4.3.10.RELEASE.jar!/:4.3.10.RELEASE]
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) ~[spring-web-4.3.10.RELEASE.jar!/:4.3.10.RELEASE]

原因

1.spring boot的应用服务在启动的时候，会生成在操作系统的/tmp目录下生成一个Tomcat.*的文件目录，用于”java.io.tmpdir”文件流操作TomcatEmbeddedServletContainerFactory
2.程序对文件的操作时：会生成临时文件，暂存在临时文件中；lunix 系统的tmpwatch 命令会删除10天未使用的临时文件；长时间不操作，导致/tmp下面的tomcat临时文件目录被删除，且删除的文件不可恢复，上传文件时获取不到文件目录，报错。

解决方案

1. 重启服务，临时方案：会重新生成tomcat目录，但是生产环境不建议如此操作。
2. 增加服务配置，自定义baseDir。
3. 启动时增加参数-Djava.io.tmpdir=自定义目录。
4. 注入一个Bean,手动配置临时目录

/**
 * 文件上传临时路径
 */
 @Bean
 MultipartConfigElement multipartConfigElement() {
    MultipartConfigFactory factory = new MultipartConfigFactory();
    factory.setLocation("/app/pttms/tmp");
    return factory.createMultipartConfig();
}