java - pretty-print XML 字符串时防止换行

Question

我使用以下代码来漂亮地打印 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;
}

我遇到的问题是它包裹了长行，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">

Answer 1

你不能。至少在使用 LSSerializer 时不会，因为它使用的 XMLSerializer 是私有(private)的，并且 LSSerializer(及其实现 DOMSerializerImpl)没有任何设置 OutputFormat 属性的方法。不过，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>