How to preserve newlines in CDATA when generating XML?

clamp picture clamp · Aug 1, 2009 · Viewed 18.2k times · Source

I want to write some text that contains whitespace characters such as newline and tab into an xml file so I use

Element element = xmldoc.createElement("TestElement");
element.appendChild(xmldoc.createCDATASection(somestring));

but when I read this back in using

Node vs =  xmldoc.getElementsByTagName("TestElement").item(0);
String x = vs.getFirstChild().getNodeValue();

I get a string that has no newlines anymore.
When i look directly into the xml on disk, the newlines seem preserved. so the problem occurs when reading in the xml file.

How can I preserve the newlines?

Thanks!

Answer

Aviad Ben Dov picture Aviad Ben Dov · Aug 8, 2009

I don't know how you parse and write your document, but here's an enhanced code example based on yours:

// creating the document in-memory                                                        
Document xmldoc = DocumentBuilderFactory.newInstance().newDocumentBuilder().newDocument();

Element element = xmldoc.createElement("TestElement");                                    
xmldoc.appendChild(element);                                                              
element.appendChild(xmldoc.createCDATASection("first line\nsecond line\n"));              

// serializing the xml to a string                                                        
DOMImplementationRegistry registry = DOMImplementationRegistry.newInstance();             

DOMImplementationLS impl =                                                                
    (DOMImplementationLS)registry.getDOMImplementation("LS");                             

LSSerializer writer = impl.createLSSerializer();                                          
String str = writer.writeToString(xmldoc);                                                

// printing the xml for verification of whitespace in cdata                               
System.out.println("--- XML ---");                                                        
System.out.println(str);                                                                  

// de-serializing the xml from the string                                                 
final Charset charset = Charset.forName("utf-16");                                        
final ByteArrayInputStream input = new ByteArrayInputStream(str.getBytes(charset));       
Document xmldoc2 = DocumentBuilderFactory.newInstance().newDocumentBuilder().parse(input);

Node vs =  xmldoc2.getElementsByTagName("TestElement").item(0);                           
final Node child = vs.getFirstChild();                                                    
String x = child.getNodeValue();                                                          

// print the value, yay!                                                                  
System.out.println("--- Node Text ---");                                                  
System.out.println(x);                                                                    

The serialization using LSSerializer is the W3C way to do it (see here). The output is as expected, with line separators:

--- XML --- 
<?xml version="1.0" encoding="UTF-16"?>
<TestElement><![CDATA[first line
second line ]]></TestElement>
--- Node Text --- 
first line
second line