Hibernate 5.3.1 版本下出现此问题：
INFO: HHH000206: hibernate.properties not found
Exception in thread "main" org.hibernate.internal.util.config.ConfigurationException: Unable to perform unmarshalling at line number 0 and column 0 in RESOURCE hibernate.cfg.xml. Message: null
at org.hibernate.boot.cfgxml.internal.JaxbCfgProcessor.unmarshal(JaxbCfgProcessor.java:133)
at org.hibernate.boot.cfgxml.internal.JaxbCfgProcessor.unmarshal(JaxbCfgProcessor.java:65)
at org.hibernate.boot.cfgxml.internal.ConfigLoader.loadConfigXmlResource(ConfigLoader.java:57)
at org.hibernate.boot.registry.StandardServiceRegistryBuilder.configure(StandardServiceRegistryBuilder.java:165)
at org.hibernate.cfg.Configuration.configure(Configuration.java:258)
at org.hibernate.cfg.Configuration.configure(Configuration.java:244)
at test.Service.saveModify(Service.java:34)
at test.App.main(App.java:15)
Caused by: javax.xml.bind.UnmarshalException
- with linked exception:
[javax.xml.stream.XMLStreamException: ParseError at [row,col]:[8,113]
Message: 对实体 "useUnicode" 的引用必须以 ';' 分隔符结尾。]
at com.sun.xml.internal.bind.v2.runtime.unmarshaller.UnmarshallerImpl.handleStreamException(UnmarshallerImpl.java:470)
at com.sun.xml.internal.bind.v2.runtime.unmarshaller.UnmarshallerImpl.unmarshal0(UnmarshallerImpl.java:448)
at com.sun.xml.internal.bind.v2.runtime.unmarshaller.UnmarshallerImpl.unmarshal(UnmarshallerImpl.java:420)
at org.hibernate.boot.cfgxml.internal.JaxbCfgProcessor.unmarshal(JaxbCfgProcessor.java:126)
... 7 more
Caused by: javax.xml.stream.XMLStreamException: ParseError at [row,col]:[8,113]
Message: 对实体 "useUnicode" 的引用必须以 ';' 分隔符结尾。
at com.sun.org.apache.xerces.internal.impl.XMLStreamReaderImpl.next(XMLStreamReaderImpl.java:596)
at com.sun.xml.internal.stream.XMLEventReaderImpl.peek(XMLEventReaderImpl.java:276)
at javax.xml.stream.util.EventReaderDelegate.peek(EventReaderDelegate.java:104)
at org.hibernate.boot.cfgxml.internal.JaxbCfgProcessor$NamespaceAddingEventReader.peek(JaxbCfgProcessor.java:254)
at com.sun.xml.internal.bind.v2.runtime.unmarshaller.StAXEventConnector.handleCharacters(StAXEventConnector.java:164)
at com.sun.xml.internal.bind.v2.runtime.unmarshaller.StAXEventConnector.bridge(StAXEventConnector.java:126)
at com.sun.xml.internal.bind.v2.runtime.unmarshaller.UnmarshallerImpl.unmarshal0(UnmarshallerImpl.java:445)
... 9 more原因：
<property name="hibernate.connection.url">标签内容格式有误：
<property name="hibernate.connection.url">jdbc:mysql://localhost:3306/lvlang?" +"autoReconnect=true&useUnicode=true&characterEncoding=UTF-8</property>后参考对实体 “characterEncoding” 的引用必须以 ‘;’ 分隔符结尾，将&符号重写成：&如下：
<property name="hibernate.connection.url">jdbc:mysql://localhost:3306/lvlang?" +"autoReconnect=true&useUnicode=true&characterEncoding=UTF-8</property>如是问题解决。
其实根据异常提示–“Message: 对实体 “useUnicode” 的引用必须以 ‘;’ 分隔符结尾”，也知道应该是useUnicode附近写的有问题。
前半截异常提示，容易误导人以为是配置文件或者标签名的问题：
INFO: HHH000206: hibernate.properties not found
Exception in thread "main" org.hibernate.internal.util.config.ConfigurationException: Unable to perform unmarshalling at line number 0 and column 0 in RESOURCE hibernate.cfg.xml. Message: null其实真正的问题出在caused by后面：
Caused by: javax.xml.stream.XMLStreamException: ParseError at [row,col]:[8,113]
Message: 对实体 "useUnicode" 的引用必须以 ';' 分隔符结尾。
at 另外，Eclipse 对于 XML 文件的错误提示，实在不友好，如上错误的 xml 写法，Eclipse 的错误提示是The word 'localhost' is not correctly spelled + The word 'lvlang' is not correctly spelled，误导人以为是localhost或者lvlang写法有问题。