xml文件有一些转义字符需要注意，转义字符如下：

&lt; The less-than character (<) starts element markup (the first character of a start-tag or an end-tag).

&amp; The ampersand character (&) starts entity markup (the first character of a character entity reference). &gt; The greater-than character (>) ends a start-tag or an end-tag. &quot; The double-quote character (") can be symbolised with this character entity reference when you need to embed a double-quote inside a string which is already double-quoted. &apos; The apostrophe or single-quote character (') can be symbolised with this character entity reference when you need to embed a single-quote or apostrophe inside a string which is already single-quoted.