maven項目裏面的web.xml開頭約束是這樣的

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xmlns="http://java.sun.com/xml/ns/javaee"
    xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd"
    id="WebApp_ID" version="2.5"
 
 />

當在後面加了東西就會報錯：

The markup in the document following the root element must be well-formed.

翻譯下錯誤：根元素後面的文檔中的標記必須很好地形成。

解決方法：

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xmlns="http://java.sun.com/xml/ns/javaee"
    xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd"
 

    id="WebApp_ID" version="2.5" ><!--這裏的“/”代表當前標簽結束啊啊啊啊-->
</web-app>

maven web項目的web.xml報錯The markup in the document following the root element must be well-formed.