问将GAE项目迁移到Java 8-在向appengine-web.xml添加运行时属性后获取XML验证错误

EN

<?xml version="1.0" encoding="utf-8"?>
<appengine-web-app xmlns="http://appengine.google.com/ns/1.0">
    <runtime>java8</runtime>
    <application>XXXAppNameXXXX</application>
    <version>2</version>
    <!-- Allows App Engine to send multiple requests to one instance in parallel: -->
    <threadsafe>true</threadsafe>

    <!-- Configure serving/caching of GWT files -->
    <static-files>
        <include path="**" />

        <!-- The following line requires App Engine 1.3.2 SDK -->
        <include path="**.nocache.*" expiration="0s" />

        <include path="**.cache.*" expiration="365d" />
        <exclude path="**.gwt.rpc" />
    </static-files>

    <!-- Configure java.util.logging -->
    <system-properties>
        <property name="java.util.logging.config.file" value="WEB INF/logging.properties" />
    </system-properties>

</appengine-web-app>