Java 打印XML字符串时防止换行

我使用以下代码漂亮地打印XML字符串：

private String prettyFormat(String xml) throws TransformerException, ParserConfigurationException, IOException, InstantiationException, IllegalAccessException, ClassNotFoundException {
     String formattedString = null;
     try {
         final InputSource src = new InputSource(new StringReader(xml));
         final Node document = DocumentBuilderFactory.newInstance().newDocumentBuilder().parse(src).getDocumentElement();
         System.setProperty(DOMImplementationRegistry.PROPERTY,"com.sun.org.apache.xerces.internal.dom.DOMImplementationSourceImpl");
         final DOMImplementationRegistry registry = DOMImplementationRegistry.newInstance();
         final DOMImplementationLS impl = (DOMImplementationLS) registry.getDOMImplementation("LS");
         final LSSerializer writer = impl.createLSSerializer();
         writer.getDomConfig().setParameter("format-pretty-print", Boolean.TRUE); 
         writer.getDomConfig().setParameter("xml-declaration", Boolean.FALSE); 
         formattedString = writer.writeToString(document); 

     } catch (Exception e) {
         throw new RuntimeException(e);
     }
   return formattedString;
}

我遇到的问题是，它将长线包裹起来，因此：

<message code="272" coeMsgName="CCR_I-Credit-Control-Initial" endtoend="AUTO" error="false" hopbyhop="AUTO" proxiable="true" request="true" retransmit="false">

变成这样：

<message code="272" coeMsgName="CCR_I-Credit-Control-Initial"
    endtoend="AUTO" error="false" hopbyhop="AUTO" proxiable="true"
    request="true" retransmit="false">

---

你不能。至少在使用LSSerializer时不是这样，因为它使用的XMLSerializer是私有的，并且LSSerializer（及其实现DOMSerializerImpl）没有任何设置OutputFormat属性的方法。但是，您可以直接使用XMLSerializer：

private static String prettyFormat(String xml) throws TransformerException, ParserConfigurationException, IOException, InstantiationException, IllegalAccessException, ClassNotFoundException {
     String formattedString = null;
     try {
         final InputSource src = new InputSource(new StringReader(xml));
         final Node document = DocumentBuilderFactory.newInstance().newDocumentBuilder().parse(src).getDocumentElement();

         // the last parameter sets indenting/pretty-printing to true:
         OutputFormat outputFormat = new OutputFormat("WHATEVER", "UTF-8", true);
         // line width = 0 means no line wrapping:
         outputFormat.setLineWidth(0);
         StringWriter sw = new StringWriter();
         XML11Serializer writer = new XML11Serializer(sw, outputFormat);
         writer.serialize((Element)document);
         formattedString = sw.toString(); 

     } catch (Exception e) {
         throw new RuntimeException(e);
     }
   return formattedString;
}

结果:

<message code="272" coeMsgName="CCR_I-Credit-Control-Initial" endtoend="AUTO" error="false" hopbyhop="AUTO" proxiable="true" request="true" retransmit="false">
    <test/>
</message>

---

我通过

javax.xml.transform.Transformer实现了这一点

public static String formatXml(Document doc) {
    try {
        Transformer transformer = TransformerFactory.newInstance().newTransformer();
        transformer.setOutputProperty(OutputKeys.INDENT, "yes");
        transformer.setOutputProperty("{http://xml.apache.org/xslt}indent-amount", "2");

        StreamResult result = new StreamResult(new StringWriter());
        DOMSource source = new DOMSource(doc);
        transformer.transform(source, result);
        return result.getWriter().toString();
    } catch (ClassCastException | TransformerException | TransformerFactoryConfigurationError e) {
        throw new IllegalArgumentException("Cannot format xml", e);
    }
}

---

似乎没有进一步的调整可用。您可以转而考虑使用自己的漂亮打印机，例如，如果没有换行后处理，则输出可能是另一种选择。-但是这种格式有什么不好的地方呢？对我来说，它非常漂亮。只需要做一个小小的更改，这一行必须更改为：

writer.serialize（（元素）文档）