Created a java application that uses Tesseract in order to convert a given image or pdf to a string format, when running it on my machine as a unit test using junit it runs grea
My guess is that there is GhostscriptException which is not logged properly, and this is causing NullPointerException:
https://github.com/nguyenq/tess4j/blob/212d72bc2ec8b3a4d4f5a18f1eb01a0622fc5521/src/main/java/net/sourceforge/tess4j/util/PdfUtilities.java#L107
106 } catch (GhostscriptException e) {
107 logger.error(e.getCause().toString(), e);
108 } finally {
In line 107 - e.getCause() is (probably) null, calling null.toString() throws NPE.
(from the specs - getCause can be null: https://docs.oracle.com/javase/7/docs/api/java/lang/Throwable.html#getCause(), GhostscriptException is also allowing the cause to be null: http://grepcode.com/file/repo1.maven.org/maven2/org.ghost4j/ghost4j/1.0.0/org/ghost4j/GhostscriptException.java)
To verify this answer (without recompiling the whole tess4j) you could start your program in the debug mode and put a breakpoint at line 107. This will give you information about the real Exception.