No metadata in generated images

[anzdaddy]

The latest server (downloaded today) outputs images without the source metadata.

$ curl -s http://localhost:8080/plantuml/png/SyfFKj2rKt3CoKnELR1Io4ZDoSclg000 > test.png
$ plantuml -metadata test.png
------------------------
test.png

null
------------------------

The plantuml.com instance and older versions (not sure how old) work fine.

[arnaudroques]

Which JDK/JRE are you using ?
When using OpenJDK, metadata are not generated (because an old Sun class is used for that which is not available on OpenJDK)
You can check your version either by:

• java -version
• java -jar plantuml.jar -version

Thanks!

[anzdaddy]

Seems to be Oracle HotSpot (running on macOS Sierra 10.12.6 (16G29), fwiw):

$ catalina run
Using CATALINA_BASE:   /usr/local/Cellar/tomcat/8.5.20/libexec
Using CATALINA_HOME:   /usr/local/Cellar/tomcat/8.5.20/libexec
Using CATALINA_TMPDIR: /usr/local/Cellar/tomcat/8.5.20/libexec/temp
Using JRE_HOME:        /Library/Java/JavaVirtualMachines/jdk1.8.0_131.jdk/Contents/Home
Using CLASSPATH:       /usr/local/Cellar/tomcat/8.5.20/libexec/bin/bootstrap.jar:/usr/local/Cellar/tomcat/8.5.20/libexec/bin/tomcat-juli.jar
⋮
07-Sep-2017 06:59:34.745 INFO [main] org.apache.catalina.startup.Catalina.start Server startup in 1277 ms
[…repeat curl && plantuml from above…]
^C
⋮
$ /Library/Java/JavaVirtualMachines/jdk1.8.0_131.jdk/Contents/Home/bin/java -version
java version "1.8.0_131"
Java(TM) SE Runtime Environment (build 1.8.0_131-b11)
Java HotSpot(TM) 64-Bit Server VM (build 25.131-b11, mixed mode)

[HeinrichAD]

The problem seems to be solved.
It tried to reproduce the issue with the following steps:

docker run -d -p 8080:8080 -e BASE_URL=plantuml plantuml/plantuml-server
curl -s http://localhost:8080/plantuml/png/SyfFKj2rKt3CoKnELR1Io4ZDoSclg000 -o test.png
curl -s -F "diagram=@test.png" http://localhost:8080/plantuml/metadata

The last command does the same as plantuml -metadata test.png only other the plantuml server instead of the java runtime file.

Output:

SyfFKj2rKt3CoKnELR1Io4ZDoSclg000

@startuml
Bob -> Alice : helloxx
@enduml

PlantUML version 1.2023.8(Sun May 21 08:38:00 UTC 2023)
(GPL source distribution)
Java Runtime: OpenJDK Runtime Environment
JVM: OpenJDK 64-Bit Server VM
Default Encoding: UTF-8
Language: en
Country: US