How to know what JDK version a project is developed on?

Question

I need to use a Java library ( https://github.com/esig/dss ) in C# using IKVM.NET. IKVM.NET supports JDK 8, how can I know if the library is using a later version? It doesn't really appear anywhere on the documentation or on the JavaDoc. Am I missing something?

Thanks in advance!

Answer 1

After compiling the Java project, to make sure which java version was used you can execute this command on one of the class file generated (javap is a binary located in your JAVA_HOME directory):

javap -verbose <Name of your class>.class | grep "major version"

Example of output:

major version: 52

And the following list will give you the mapping between the major version and the java version:

• Java 5 uses major version 49
• Java 6 uses major version 50
• Java 7 uses major version 51
• Java 8 uses major version 52
• Java 9 uses major version 53
• Java 10 uses major version 54
• Java 11 uses major version 55
• etc...