使用 Transformer 制作的缩进 XML

Question

我正在尝试从 Java 创建 XML，但遇到缩进问题。在下面的代码中你可以看到 OutputKeys.INDENT 设置为 yes...

        //set up a transformer
        TransformerFactory transfac = TransformerFactory.newInstance();
        Transformer trans = transfac.newTransformer();
        trans.setOutputProperty(OutputKeys.OMIT_XML_DECLARATION, "yes");
        trans.setOutputProperty(OutputKeys.INDENT, "yes");

        //create string from xml tree
        StringWriter sw = new StringWriter();
        StreamResult result = new StreamResult(sw);
        DOMSource source = new DOMSource(doc);
        trans.transform(source, result);
        String xmlString = sw.toString();

        //print xml
        System.out.println(xmlString);

但它似乎没有影响，输出是：

<dataset id="1"><br>
<path></path><br>
<session id="1"><br>
<method><br>
<timestamp>a timestamp</timestamp><br>
<signiture><br>
<classPath></classPath><br>
<name>methodName</name><br>
<declarationType>String</declarationType><br>
<parameters><br>
<parameter>String</parameter><br>
<parameter>int</parameter><br>
</parameters><br>
</signiture><br>
<arguments><br>
<argument>SomeValue</argument><br>
<argument>AnotherValue</argument><br>
</arguments><br>
<return>ReturnValue</return><br>
</method><br>
</session><br>
</dataset><br>

Answer 1

尝试设置 indent-amount，据我所知默认是 0。

trans.setOutputProperty("{http://xml.apache.org/xslt}indent-amount", "4")

Answer 2

Document doc;

.....

TransformerFactory factory = TransformerFactory.newInstance();
Transformer transformer = factory.newTransformer();
transformer.setOutputProperty(OutputKeys.INDENT, "yes");
transformer.setOutputProperty("{http://xml.apache.org/xslt}indent-amount", "4");
transformer.transform(new DOMSource(doc), new StreamResult(new File("filename.xml")));
transformer.transform(new DOMSource(doc), new StreamResult(System.out));