Java说XML文档不成形

Question

Java的XML解析器似乎认为我的XML文档在根元素之后没有很好地形成.但是我已经用几种工具对它进行了验证,他们都不同意.这可能是我的代码中的错误,而不是文档本身.我非常感谢你们能给我的任何帮助.

这是我的Java方法:

private void loadFromXMLFile(File f) throws ParserConfigurationException, IOException, SAXException {
    File file = f;
    DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();
    DocumentBuilder db;
    Document doc = null;
    db = dbf.newDocumentBuilder();
    doc = db.parse(file);
    doc.getDocumentElement().normalize();
    String desc = "";
    String due = "";
    String comment = "";
    NodeList tasksList = doc.getElementsByTagName("task");
    for (int i = 0; i  tasksList.getLength(); i++) {
        NodeList attributes = tasksList.item(i).getChildNodes();
        for (int j = 0; i < attributes.getLength(); j++) {
        Node attribute = attributes.item(i);
        if (attribute.getNodeName() == "description") {
            desc = attribute.getTextContent();
        }
        if (attribute.getNodeName() == "due") {
            due = attribute.getTextContent();
        }
        if (attribute.getNodeName() == "comment") {
            comment = attribute.getTextContent();
        }
        tasks.add(new Task(desc, due, comment));
        }
        desc = "";
        due = "";
        comment = "";
    }
}

以下是我正在尝试加载的XML文件:

<?xml version="1.0"?>  
<tasklist>  
    <task>  
        <description>Task 1</description>  
        <due>Due date 1</due>  
        <comment>Comment 1</comment>  
        <completed>false</completed>  
    </task>  
    <task>  
        <description>Task 2</description>  
        <due>Due date 2</due>  
        <comment>Comment 2</comment>  
        <completed>false</completed>  
    </task>  
    <task>  
        <description>Task 3</description>  
        <due>Due date 3</due>  
        <comment>Comment 3</comment>  
        <completed>true</completed>  
    </task>  
</tasklist>

这是java为我抛出的错误消息:

run:
[Fatal Error] tasks.xml:28:3: The markup in the document following the root element must be well-formed.
May 17, 2010 6:07:02 PM todolist.TodoListGUI <init>
SEVERE: null
org.xml.sax.SAXParseException: The markup in the document following the root element must be well-formed.
        at com.sun.org.apache.xerces.internal.parsers.DOMParser.parse(DOMParser.java:239)
        at com.sun.org.apache.xerces.internal.jaxp.DocumentBuilderImpl.parse(DocumentBuilderImpl.java:283)
        at javax.xml.parsers.DocumentBuilder.parse(DocumentBuilder.java:208)
        at todolist.TodoListGUI.loadFromXMLFile(TodoListGUI.java:199)
        at todolist.TodoListGUI.<init>(TodoListGUI.java:42)
        at todolist.Main.main(Main.java:25)
BUILD SUCCESSFUL (total time: 19 seconds)

供参考TodoListGUI.java:199是

doc = db.parse(file);

如果上下文对这里的任何人都有帮助,我正在尝试编写一个简单的GUI应用程序来管理todo列表,该列表可以读取和写入定义任务的XML文件.

Answer 1

org.xml.sax.SAXParseException:根元素后面的文档中的标记必须格式正确.

此特殊异常表示XML文档中有多个根元素.换句话说,<tasklist>它不是唯一的根元素.以XML文档为例,考虑一个没有<tasklist>元素并且<task>根目录中有三个元素的文档.这会导致这种异常.

由于您发布的XML文件看起来很好,问题出在其他地方.看起来它没有解析你期望解析的XML文件.要进行快速调试,请将以下内容添加到方法的顶部:

System.out.println(f.getAbsolutePath());

在磁盘文件系统中找到该文件并进行验证.

Answer 2

尝试将 XML 声明更改为：

<?xml version="1.0" encoding="UTF-8" ?>