# 最大支援檔案大小
spring.http.multipart.max-file-size=100MB
# 最大支援請求大小
spring.http.multipart.max-request-size=100MB

對照官方文件設定沒問題啊

# MULTIPART (MultipartProperties)
spring.http.multipart.enabled=true # Enable support of multi-part uploads.
spring.http.multipart.file-size-threshold=0 # Threshold after which files will be written to disk. Values can use the suffixed "MB" or "KB" to indicate a Megabyte or Kilobyte size.
spring.http.multipart.location= # Intermediate location of uploaded files.
spring.http.multipart.max-file-size=1MB # Max file size. Values can use the suffixed "MB" or "KB" to indicate a Megabyte or Kilobyte size.
spring.http.multipart.max-request-size=10MB # Max request size. Values can use the suffixed "MB" or "KB" to indicate a Megabyte or Kilobyte size.
spring.http.multipart.resolve-lazily=false # Whether to resolve the multipart request lazily at the time of file or parameter access.
 

後來發現我的專案中springboot由原來的1.5.3升級到2.0.5了。。看下了下2.0.5文件是醬紫的。。。

# MULTIPART (MultipartProperties)
spring.servlet.multipart.enabled=true # Whether to enable support of multipart uploads.
spring.servlet.multipart.file-size-threshold=0 # Threshold after which files are written to disk. Values can use the suffixes "MB" or "KB" to indicate megabytes or kilobytes, respectively.
spring.servlet.multipart.location= # Intermediate location of uploaded files.
spring.servlet.multipart.max-file-size=1MB # Max file size. Values can use the suffixes "MB" or "KB" to indicate megabytes or kilobytes, respectively.
spring.servlet.multipart.max-request-size=10MB # Max request size. Values can use the suffixes "MB" or "KB" to indicate megabytes or kilobytes, respectively.
spring.servlet.multipart.resolve-lazily=false # Whether to resolve the multipart request lazily at the time of file or parameter access.
 

改成spring.servlet就好了