Exception in thread "main" java.lang.UnsupportedClassVersionError: net/sourceforge/lept4j/Boxa : Unsupported major.minor version 52.0

[SylvesterJo]

Exception in thread "main" java.lang.UnsupportedClassVersionError: net/sourceforge/lept4j/Boxa : Unsupported major.minor version 52.0

[nguyenq]

Yes, it was compiled with JDK 1.8. To the best of my recollection, the library is not using any Java 1.8-specific API, so you can certainly rebuild it with JDK 1.7, which a developer successfully did recently.

We probably will downgrade to JDK 1.7 for the next release to accommodate larger user base.

Thanks.

[SylvesterJo]

I checked the jars being used by the tess4j jna wrapper like lept4j, tess4j, jna, etc. All have the manifest saying these have been compiled using Java 1.8. So kindly suggest will I have to get the source Java files for these and recompile these with Java 1.7 to make this exception go away?

Regards
Sylvester

[nguyenq]

All of them are available right here on github. lept4j and tess4j are straighforward to build using Maven. I can't speak for jna, though.

Quan

[nguyenq]

1.3.1 has been compiled using JDK 1.8 but targeted to 1.7.