Caused by: org.springframework.beans.NotWritablePropertyException: Invalid property 'userDao' of bean class [tarena.service.UserServiceImpl]: Bean property 'userDao' is not writable or has an invalid setter method. Does the parameter type of the setter match the return type of the getter?	at org.springframework.beans.BeanWrapperImpl.setPropertyValue(BeanWrapperImpl.java:801)	at org.springframework.beans.BeanWrapperImpl.setPropertyValue(BeanWrapperImpl.java:651)	at org.springframework.beans.AbstractPropertyAccessor.setPropertyValues(AbstractPropertyAccessor.java:78)	at org.springframework.beans.AbstractPropertyAccessor.setPropertyValues(AbstractPropertyAccessor.java:59)	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.applyPropertyValues(AbstractAutowireCapableBeanFactory.java:1276)	... 16 more

错误原因已经很明显了，userDao没有一个set方法，在tarena.service.UserServiceImpl中添加如下代码即可

 

private UserDAO userDao;    	public void setUserDao(UserDAO userDao) {		this.userDao = userDao;	}