填坑之Multipart文件上传临时文件找不到路径

填坑之Multipart文件上传临时文件找不到路径

异常描述

春节过后，生产报了个异常：

主要是这句：The temporary upload location …… is not valid ！临时的上传路径不可用，在服务器上找了一下，这个路径确实不存在，应该是文件丢失了

处理异常 异常原因

SpringBoot项目启动后，系统默认会在 /tmp 目录下自动创建如下三个目录：

 hsperfdata_root，
 tomcat.************.8080,(结尾是项目的端后)
 tomcat-docbase.*********.8080
 
 注: Multipart（form-data）的方式处理请求时，默认就是在第二个目录下创建临时文件的

CentOS7会定期自动清理/tmp路径下的文件，清理规则如下：

[eccore@vm035vmt006 /]$ cat /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 		 # 清理/tmp下10天前的目录和文件
v /var/tmp 1777 root root 30d	 # 清理/var/tmp下30天前的目录和文件
# Exclude namespace mountpoints created with PrivateTmp=yes
# 以下为排出清理的文件
x /tmp/systemd-private-%b-*
X /tmp/systemd-private-%b-*/tmp
x /var/tmp/systemd-private-%b-*
X /var/tmp/systemd-private-%b-*/tmp

原因找到了，系统清理缓存导致，故要么限制系统清理缓存策略文件删除时找不到路径，要么将临时文件上传路径变更到其他路径即可！

异常处理 修改清理策略

不推荐！多台服务器均需修改，而且会遗留很多垃圾文件!

简单暴力，直接修改系统清理策略，在文件末尾添加排出此文件夹：

x /tmp/tomcat.*

启动脚本指定

不推荐！启动命令不方便维护，如果使用自动化部署可以考虑！

DIR=/home/Genterator
FILETMPDIR=${DIR}/FILETMPDIR
nohup java -Xms2048m -Xmx2048m -jar genterator.1.0.0-1.jar --spring.profiles.active=test --server.port=9820 -java.tmp.dir=$FILETMPDIR 2>1&

配置文件指定

推荐！

在properties或者yml中指定：spring.servlet.multipart.location，如下：

spring.servlet.multipart.max-file-size = 20MB
spring.servlet.multipart.max-request-size=100MB
spring.servlet.multipart.location=/home/eccore/tmp

经测试，Linux是可以的文件删除时找不到路径，将缓存文件放入指定路径，但Windows作为开发环境存在异常（可能是我的环境导致，未验证）：

[2023-01-31 14:15:43.309] [traceid:e4cdabdc06fb1d5c] [spanId:e4cdabdc06fb1d5c] [http-nio-8084-exec-1] [ERROR] [cn.yto.exceptions.ExceptionCatch:261] -- >>> url:/webApi/finance/ordinaryBill/autoReconciliation, case:Failed to parse multipart servlet request; nested exception is java.io.IOException: The temporary upload location [C:\Users\yto\AppData\Local\Temp\tomcat.6215628767972368797.8084\work\Tomcat\localhost\webApi\home\eccore\tmp] is not valid
org.springframework.web.multipart.MultipartException: Failed to parse multipart servlet request; nested exception is java.io.IOException: The temporary upload location [C:\Users\yto\AppData\Local\Temp\tomcat.6215628767972368797.8084\work\Tomcat\localhost\webApi\home\eccore\tmp] is not valid
	at org.springframework.web.multipart.support.StandardMultipartHttpServletRequest.handleParseFailure(StandardMultipartHttpServletRequest.java:123)
	at org.springframework.web.multipart.support.StandardMultipartHttpServletRequest.parseRequest(StandardMultipartHttpServletRequest.java:114)
	at org.springframework.web.multipart.support.StandardMultipartHttpServletRequest.<init>(StandardMultipartHttpServletRequest.java:87)
	at org.springframework.web.multipart.support.StandardServletMultipartResolver.resolveMultipart(StandardServletMultipartResolver.java:87)
	at org.springframework.web.servlet.DispatcherServlet.checkMultipart(DispatcherServlet.java:1175)
	at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:1010)
	at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:942)
	at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:1005)
	at org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:908)
	at javax.servlet.http.HttpServlet.service(HttpServlet.java:660)
	at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:882)
	at javax.servlet.http.HttpServlet.service(HttpServlet.java:741)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:231)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
	at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:53)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
	at brave.servlet.TracingFilter.doFilter(TracingFilter.java:65)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
	at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:101)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
	at com.alibaba.druid.support.http.WebStatFilter.doFilter(WebStatFilter.java:123)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
	…………

Spring注解指定

强烈推荐！

通过SpringBoot的注解@Configuration指定配置类，将对应Bean(MultipartConfigElement)对象注入容器中，替换原来的Bean， 新注入的Bean中指定缓存存放路径！

package cn.yto.steward.config;
import lombok.extern.slf4j.Slf4j;
import org.springframework.boot.web.servlet.MultipartConfigFactory;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import javax.servlet.MultipartConfigElement;
import java.io.File;
/**
 * 文件上传配置
 *
 * @author YTO
 * @date 2023年01月31日 13:43
 */
@Slf4j
@Configuration
public class MultipartConfig {
    /**
     * 文件上传临时路径
     */
    @Bean
    MultipartConfigElement multipartConfigElement() {
        MultipartConfigFactory factory = new MultipartConfigFactory();
        String location = System.getProperty("user.home") + File.separator + "tmp";
        log.info("文件上传临时路径:{}", location);
        File tmpFile = new File(location);
        if (!tmpFile.exists()) {
            boolean mkdirs = tmpFile.mkdirs();
            log.info("创建文件上传临时路径:{}, 创建结果:{}", location, mkdirs);
        }
        factory.setLocation(location);
        return factory.createMultipartConfig();
    }
}