java - fatal error :1:1: Content is not allowed in prolog. org.xml.sax.SAXParseException

Question

我正在尝试用 Java 读取一个 XML 文件，然后将它与它的 XML 模式进行比较，但我无法克服这个错误:

[Fatal Error] :1:1: Content is not allowed in prolog. org.xml.sax.SAXParseException; lineNumber: 1; columnNumber: 1; Content is not allowed in prolog.

这是文件读取的开始

try {
        DocumentBuilderFactory dbFactory = DocumentBuilderFactory.newInstance();
        DocumentBuilder dBuilder = dbFactory.newDocumentBuilder();          
        Document doc = dBuilder.parse(new InputSource(new StringReader("myfile.xml"))); // ERROR OCCURS HERE

我用HEX Editors扫描了我的XML，但我没有在里面发现任何奇怪的字符，所以我不知道问题出在哪里

我的文件.xml

<?xml version="1.0" encoding="UTF-8" standalone="no"?>

<Schedule xmlns ="schedule"
          xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
          xsi:noNamespaceSchemaLocation="schedule.xsd">
    <Lesson>
        <Title>Artificial Intelligence</Title>
        <Lecture Classroom="BA">
            <Day>Wednesday</Day>
            <Time>09-11</Time>
        </Lecture>
        <Professor>Hatzilygeroudis</Professor>
    </Lesson>
    <Lesson>
        <Title>Constraint Satisfaction Problems</Title>
        <Lecture Classroom="B3">
            <Day>Monday</Day>
            <Time>19-21</Time>
        </Lecture>
    </Lesson>
    <Lesson>
        <Title>Knowledge Representation in Web</Title>
        <Lecture Classroom="P200">
            <Day>Friday</Day>
            <Time>15-17</Time>
        </Lecture>
        <Professor>Hatzilygeroudis</Professor>
    </Lesson>
    <Lesson>
        <Title>Artificial Intelligence</Title>
        <Lecture>
            <Day>Monday</Day>
            <Time>19-21</Time>
        </Lecture>
    </Lesson>
    <Lesson>
        <Title>AI Programming</Title>
        <Lecture Classroom="B3">
            <Day>Monday</Day>
            <Time>11-13</Time>
        </Lecture>
    </Lesson>
    <Lesson>
        <Title>Introduction to Procedural Programming</Title>
        <Lecture Classroom="P200">
            <Day>Wednesday</Day>
            <Time>15-17</Time>
        </Lecture>
        <Professor>Papadopoulos</Professor>
    </Lesson>
</Schedule>

Answer 1

StringReader("myfile.xml") 采用必须为 XML 的字符串参数，而不是文件名。解析器正在读取字符串文字 myfile.xml(不是 myfile.xml 的文件内容)并立即失败，因为 XML 文档可能不是以 开头>m 字符。

改变

Document doc = dBuilder.parse(new InputSource(new StringReader("myfile.xml")));

到

Document doc = dBuilder.parse(new InputSource("myfile.xml"));