将“http://java.sun.com/xml/ns/persistence/persistence_2_1.xsd”下载到 C:/<path> 时出错

如何解决将“http://java.sun.com/xml/ns/persistence/persistence_2_1.xsd”下载到 C:/<path> 时出错

我有以下persistence.xml文件

<?xml version="1.0" encoding="UTF-8"?>
<persistence version="2.1" 
     xmlns="http://java.sun.com/xml/ns/persistence" 
     xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 
     xsi:schemaLocation="http://java.sun.com/xml/ns/persistence 
     http://java.sun.com/xml/ns/persistence/persistence_2_1.xsd">
 <persistence-unit name="<>">
      <class>com.myApplication.MyFristApp</class>
      <class>com.myApplication.MyFristApp</class>
 </persistence-unit>

而我所拥有的是 爪哇 11,Eclipse 4.16 光子， 雄猫9

当我尝试从 Java 8 迁移到 Java 11 时，我在标签上收到以下错误

Error while downloading 'http://java.sun.com/xml/ns/persistence/persistence_2_1_.xsd' to C:\users\kishore\.lemminx/cache\http\java.sun.com\....

我正在尝试这个发现这几天。无法解决。