c3p0 reports java.lang.NoClassDefFoundError

• The reason for the error is separated after the c3p0-0.9.2 version, and the com-mchange-java package needs to be imported
• Solution:

1. [Test success] Use my version without separation of 0.9.1.2 https://www.lanzous.com/i5mbv7g
2. [No test too lazy to test] Go and download the jar package of com-mchange-java http://www.java2s.com/Code/Jar/m/mchange.htm