转：http://hybxiaodao.iteye.com/blog/1169168
你如果点中单独一个文件，那么那个选项一直都是反灰，只有你点中整个项目名，那个选项就可用了。
不是什么版本问题
用myEclipse搭建hibernate框架后，有时搞乱了某些东西后，又想重新加载Hibernate包，但此时 addhibernate capabilities功能菜单竟然是灰色的，不可用，尤其是初学的朋友往往要重建web项目，一切都要重新来过。
其实大可不必这么做。有个简单的方法可以解决这个问题：
切换到java的导航试图，在项目的根目录下又个项目配置文件：".project"，打开后如下代码所示。
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<?xml version="1.0"encoding="UTF-8"?>
<projectDescription>
<name>CourseMS</name>
<comment></comment>
<projects>
</projects>
<buildSpec>
<buildCommand>
<name>com.genuitec.eclipse.j2eedt.core.WebClasspathBuilder</name>
<arguments>
</arguments>
</buildCommand>
<buildCommand>
<name>org.eclipse.jdt.core.javabuilder</name>
<arguments>
</arguments>
</buildCommand>
<buildCommand>
<name>com.genuitec.eclipse.j2eedt.core.J2EEProjectValidator</name>
<arguments>
</arguments>
</buildCommand>
<buildCommand>
<name>com.genuitec.eclipse.j2eedt.core.DeploymentDescriptorValidator</name>
<arguments>
</arguments>
</buildCommand>
<buildCommand>
<name>org.eclipse.wst.validation.validationbuilder</name>
<arguments>
</arguments>
</buildCommand>
<buildCommand>
<name>com.genuitec.eclipse.hibernate.HibernateBuilder</name>
<arguments>
</arguments>
</buildCommand>
</buildSpec>
<natures>
<nature>com.genuitec.eclipse.hibernate.hibernatenature</nature>
<nature>com.genuitec.eclipse.j2eedt.core.webnature</nature>
<nature>org.eclipse.jdt.core.javanature</nature>
<nature>org.eclipse.wst.jsdt.core.jsNature</nature>
</natures>
</projectDescription>
<?xml version="1.0"encoding="UTF-8"?>
<projectDescription>
<name>CourseMS</name>
<comment></comment>
<projects>
</projects>
<buildSpec>
<buildCommand>
<name>com.genuitec.eclipse.j2eedt.core.WebClasspathBuilder</name>
<arguments>
</arguments>
</buildCommand>
<buildCommand>
<name>org.eclipse.jdt.core.javabuilder</name>
<arguments>
</arguments>
</buildCommand>
<buildCommand>
<name>com.genuitec.eclipse.j2eedt.core.J2EEProjectValidator</name>
<arguments>
</arguments>
</buildCommand>
<buildCommand>
<name>com.genuitec.eclipse.j2eedt.core.DeploymentDescriptorValidator</name>
<arguments>
</arguments>
</buildCommand>
<buildCommand>
<name>org.eclipse.wst.validation.validationbuilder</name>
<arguments>
</arguments>
</buildCommand>
<buildCommand>
<name>com.genuitec.eclipse.hibernate.HibernateBuilder</name>
<arguments>
</arguments>
</buildCommand>
</buildSpec>
<natures>
<nature>com.genuitec.eclipse.hibernate.hibernatenature</nature>
<nature>com.genuitec.eclipse.j2eedt.core.webnature</nature>
<nature>org.eclipse.jdt.core.javanature</nature>
<nature>org.eclipse.wst.jsdt.core.jsNature</nature>
</natures>
</projectDescription>
一般在最下方有：
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<buildCommand>
<name>com.genuitec.eclipse.hibernate.HibernateBuilder</name>
<arguments>
</arguments>
</buildCommand>
<buildCommand>
<name>com.genuitec.eclipse.hibernate.HibernateBuilder</name>
<arguments>
</arguments>
</buildCommand>
和
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<nature>com.genuitec.eclipse.hibernate.hibernatenature</nature>
<nature>com.genuitec.eclipse.hibernate.hibernatenature</nature>
将这两段删除即可
