How to change JAXB Marshaller line separator?

Question

What property is used to change the Marshaller (javax.xml.bind.Marshaller) line separator (carriage return, new line, line break)?

I believe the marshaller is using the systems's line separator.

System.getProperty("line.separator")

However a different escape sequence is needed (i.e. \r\n needs to be changed to \n or vice versa).

marshaller.setProperty(Marshaller.JAXB_FORMATTED_OUTPUT, true);

marshaller.setProperty("line.separator", "\r\n");

Answer 1

There is no a property that you can customize. Most implementations send directly to the buffer the line separator:

write('\n');

However, you can replace the result.

Marshaller marshaller = ctx.createMarshaller();
marshaller.setProperty(Marshaller.JAXB_FORMATTED_OUTPUT, true);
marshaller.setProperty(Marshaller.JAXB_ENCODING, "UTF-8");

StringWriter writer = new StringWriter(1024); // 2 KB
marshaller.marshal(obj, writer);

String str = writer.toString();
str = str.replaceAll("\r?\n", "\r\n");  // only convert if necessary

To avoid any effect on the performance, you must set the approximate size (e.g. 1024 -> 2 KB) in the constructor for java.io.StringWriter.