<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE hr SYSTEM "hr.dtd">
<hr>
   <employee no="3309">
       <name>张三</name>
       <age>31</age>
       <salary>4000</salary>
       <department>
           <dname>会计部</dname>
           <address>xx区-B103</address>
       </department>
   </employee>
   <employee no="3309”">
       <name>李四</name>
       <age>32</age>
       <salary>5000</salary>
       <department>
           <dname>美工部</dname>
           <address>xx区-B102</address>
       </department>
   </employee>
</hr>

<?xml version="1.0" encoding="UTF-8" ?>
<!ELEMENT hr (employee)>

我用的编译器是IDEA，但是会报错，就算添加了+号一样是报错，并且不是因为多了个冒号