异常处理

1.The processing instruction target matching "[xX][mM][lL]" is not allowed.

XML 中报错，该错误的意思是，<?xml version="1.0" encoding="UTF-8" ?> 这句之前不能有任何字符包括空格

2.No grammar constraints (DTD or XML schema) detected for the document

XML中报错，dtd验证是xml的规范

一般IDE环境中配置档的最前面都是DTD 或 XML 打头的。比如
< ?xml version="1.0" encoding="UTF-8"?>
< !DOCTYPE hibernate-configuration PUBLIC
"-//Hibernate/Hibernate Configuration DTD 3.0//EN"
"http://hibernate.sourceforge.net/hibernate-configuration-3.0.dtd">

要去除警告的话：工具栏：windows => preferences => xml => xml files => validation => Indicate when no grammar is specified:选择Ignore即可。

3.The type java.util.Map$Entry cannot be resolved. It is indirectly referenced from required .class files

原因是JDK jre版本过高