log4j:WARN No appenders could be found for logger (org.hibernate.cfg.Environment).
log4j:WARN Please initialize the log4j system properly.
Exception in thread "main" org.hibernate.TypeMismatchException: Provided id of the wrong type for class pojo.Books. Expected: class java.lang.Integer, got class java.lang.Long
at org.hibernate.event.def.DefaultLoadEventListener.onLoad(DefaultLoadEventListener.java:109)
at org.hibernate.impl.SessionImpl.fireLoad(SessionImpl.java:906)
at org.hibernate.impl.SessionImpl.get(SessionImpl.java:843)
at org.hibernate.impl.SessionImpl.get(SessionImpl.java:836)
at test.test.sessions(test.java:34)
at test.test.main(test.java:55)
创建数据库，id 为int
创建数据库的表：CREATE TABLE books(id INT PRIMARY KEY auto_increment,Bookname VARCHAR(50),Bookprice VARCHAR(40));
Books bookFirst = (Books)session.get(Books.class, new Long(1));
这是因为 数据库id为integer与long类型数据不匹配！
修改.hbm.xml
修改主键数据类型为long