SpringBoot文件上传异常之提示The temporary upload location xxx is not valid

方法1

• 应用重启

方法2

• 增加服务配置，自定义baseDir

server.tomcat.basedir=/tmp/tomcat

方法3

• 注入bean，手动配置临时目录

@Bean
MultipartConfigElement multipartConfigElement() {
    MultipartConfigFactory factory = new MultipartConfigFactory();
    factory.setLocation("/tmp/tomcat");
    return factory.createMultipartConfig();
}

方法4

• 配置不删除tmp目录下的tomcat

vim /usr/lib/tmpfiles.d/tmp.conf

# 添加一行
x /tmp/tomcat.*

什么地方缓存文件

org.apache.tomcat.util.http.fileupload.FileUploadBase#parseRequest

为什么目录会不存在

springboot启动时会创建一个/tmp/tomcat.*/work/Tomcat/localhost/ROOT的临时目录作为文件上传的临时目录，但是该目录会在n天之后被系统自动清理掉，这个清理是由linux操作系统完成的，具体的配置如下 vim /usr/lib/tmpfiles.d/tmp.conf

#  This file is part of systemd.
#
#  systemd is free software; you can redistribute it and/or modify it
#  under the terms of the GNU Lesser General Public License as published by
#  the Free Software Foundation; either version 2.1 of the License, or
#  (at your option) any later version.

# See tmpfiles.d(5) for details

# Clear tmp directories separately, to make them easier to override
v /tmp 1777 root root 10d
v /var/tmp 1777 root root 30d

# Exclude namespace mountpoints created with PrivateTmp=yes
x /tmp/systemd-private-%b-*
X /tmp/systemd-private-%b-*/tmp
x /var/tmp/systemd-private-%b-*
X /var/tmp/systemd-private-%b-*/tmp

为什么要缓存文件

因为流取一次消费之后，后面无法再从流中获取数据，所以缓存方便后续复用；