1.Caused by: org.xml.sax.SAXParseException: Content is not allowed in prolog.
原因：beans.xml书写格式有误
解决方法：原来在xml文件开头多了个a删除即可
2.Caused by: java.lang.IllegalArgumentException: No PersistenceProvider specified in EntityManagerFactory configuration, and chosen PersistenceUnitInfo does not specify a provider class name either
the hibernate documention says:
The provider is a fully-qualified class name of the EJB Persistence provider. You do not have to define it if you don’t work with several EJB3 implementations. This is needed when you are using multiple vendor implementations of EJB Persistence.
添加上<provider>org.hibernate.ejb.HibernatePersistence</provider>这一句即可：
<?xml version=”1.0″ encoding=”UTF-8″?>
<persistence xmlns=”http://java.sun.com/xml/ns/persistence”
xmlns:xsi=”http://www.w3.org/2001/XMLSchema-instance”
xsi:schemaLocation=”http://java.sun.com/xml/ns/persistence http://java.sun.com/xml/ns/persistence/persistence_2_0.xsd”
version=”2.0″>
<persistence-unit name=”galleryPersistenceUnit”>
<provider>org.hibernate.ejb.HibernatePersistence</provider>
</persistence-unit>
</persistence>
3.eclipse的一个bug在使用return on…(onclick,onsubmit或者其他)javascript的时候会报错，提示:Cannot return from outside a function or method。其实没有问题，现在只能不必管他。