从命令行运行JAR而不是从IDE运行JAR会导致NullPointerException的原因是什么？

I have a project in Eclipse. When I run it from inside Eclipse, everything works just fine. However, when I run the Ant build script and execute the JAR either from the command line or using a batch script, I get a NullPointerException.I have a project in Eclipse. When I run it from