Exception in thread "main" java.lang.NoClassDefFoundError: org/apache/commons/collections4/ListValuedMap at org.apache.poi.ss.usermodel.WorkbookFactory.create(WorkbookFactory.java:181) at org.apache.poi.ss.usermodel.WorkbookFactory.create(WorkbookFactory.java:140) at com.baidu.common.Excel.main(Excel.java:18) Caused by: java.lang.ClassNotFoundException: org.apache.commons.collections4.ListValuedMap at java.net.URLClassLoader.findClass(URLClassLoader.java:381) at java.lang.ClassLoader.loadClass(ClassLoader.java:424) at sun. misc.Launcher$AppClassLoader.loadClass(Launcher.java:331) at java.lang.ClassLoader.loadClass(ClassLoader.java:357) ... 3 more