我尝试从 xsd 生成类，但第二行出现问题
<?xml version="1.0" encoding="UTF-8"?>
<xs:schema xmlns:saqcc="urn:saq:cct:cct-3.5.xsd" xmlns:flx="urn:saq:mtl:grey:flux:04489:rep-1.0.xsd" xmlns:xs="http://www.w3.org/2001/XMLSchema" targetNamespace="urn:saq:mtl:grey:flux:04489:rep-1.0.xsd" elementFormDefault="qualified" attributeFormDefault="unqualified" version="1.1">
...
我收到了这个错误：
[错误] prolog 中不允许有内容。所以 xjc 似乎有架构问题
这个xsd有一个导入，在这个导入中还有另一个导入......所以我不知道如果xjc能够管理那个错误什么时候会被删除......
我遇到了这个问题，结果发现编码是问题：
<?xml version="1.0" encoding="utf-8"?>
有效，但
<?xml version="1.0" encoding="utf-16"?>
没有（至少在我的 Windows7/64 位操作系统上）。
When I get this error with any sort of XML document, it's usually because of some (invisible) content before <?xml. More specifically, this is due to the BOM (byte order mark) added by some editor. In my case, it was mostly due to this BOM: 
Check if you have such content in your file. If you do, remove it. XML files don't need a BOM, as they can formally specify the encoding in the prolog like this:
<?xml version="1.0" encoding="utf-8"?>
UPDATE: The prolog MUST be the first part of well-formed XML, as defined by w3c here: