作业帮java.lang.NullPointerException at dao.booDAO.addbook(booDAO.java:23) at org.apache.jsp.addbookok_js
来源：学生作业帮助网 编辑：作业帮 时间：2024/05/03 13:17:24
java.lang.NullPointerException at dao.booDAO.addbook(booDAO.java:23) at org.apache.jsp.addbookok_js
java.lang.NullPointerException at dao.booDAO.addbook(booDAO.java:23) at org.apache.jsp.addbookok_js
java.lang.NullPointerException at dao.booDAO.addbook(booDAO.java:23) at org.apache.jsp.addbookok_js
你的booDAO对象为null
检查你的代码