XStream and underscores

Question

It looks like XStream (com.thoughtworks.xstream -> xstream 1.4.2) is handling underscores in element and attribute names in a very strange way. I need to fetch and parse an xml from a customer that are having underscores in their attributes. This is my first try with XStream and I'm a bit disappointed as I was hoping to avoid all the ugly xml parsing.

Here I provide a small test sample to hi light the behaviour. The last example shows my problem.

public class MyTest {
  public void testIt() {
    C1 a = new C1();
    a.a_b= "a_b";

    XStream xstream = new XStream();
    xstream.processAnnotations(C1.class);

    String xml = xstream.toXML(a);
    Logger.info(xml);

    C1 b = (C1) xstream.fromXML(xml);
    Logger.info(b.a_b);

    C1 c = (C1) xstream.fromXML("<C1 a_b=\"a_b\"/>");
    Logger.info(c.a_b);
  }
}

@XStreamAlias("C1")
class C1 {
@XStreamAsAttribute
String a_b;
}

This outputs

INFO: <C1 a__b="a_b"/>
INFO: a_b
INFO: null

Now my question - is there a way to make XStream understand a single underscore?

score 20 · Answer 1 · answered Jul 04 '12 at 19:01

20

This worked for me:

XStream xs = new XStream(new DomDriver("UTF-8", new XmlFriendlyNameCoder("_-", "_")));

answered Jul 04 '12 at 19:01

James Young

1,372
13
16

Worked for me. XmlFriendlyReplacer() is depricated. – Sachin Sharma Oct 24 '13 at 11:07
Awesome. Worked great. – Dan Torrey Mar 12 '15 at 19:50
Thanks it's really helpful – Narendra Rabari Oct 09 '15 at 10:40

score 12 · Accepted Answer · edited Aug 24 '16 at 17:31

12

XStream uses the underscore to escape characters in identifiers that are valid in Java but invalid in XML (see here). So the underscore itself has to be escaped. You can use a custom NameCoder as described in the FAQ.

That said I normally can get along with the NoNameCoder. But: Don't use underscores in Java property identifiers, if possible; it is untypical for Java and against the Java Naming Conventions.

edited Aug 24 '16 at 17:31

facundofarias

2,973
28
27

answered Feb 17 '12 at 18:17

Hauke Ingmar Schmidt

11,559
1
42
50

Thanks very much. XStream(new StaxDriver(new NoNameCoder())) didn't work so I'll investigate making a custom one. – eigil Feb 17 '12 at 18:53
NoNameCoder does work. I just forgot to add @XStreamAlias("a_b") to the variable when I changed it to ab based on your suggestion about java naming conventions. – eigil Feb 20 '12 at 16:50

score 5 · Answer 3 · answered Nov 12 '13 at 13:20

5

I used:

XmlFriendlyNameCoder nameCoder = new XmlFriendlyNameCoder("ddd", "_");  
XStream xmlStream = new XStream(new Dom4JDriver(nameCoder));

and it worked great! I am using x-stream version 1.4.5. Hope it helps!

answered Nov 12 '13 at 13:20

Luismi Lainez

151
2
2

`XStream xs=new XStream (new Dom4JDriver (new NoNameCoder()));` works for 1.4.4 – youngzy Oct 29 '19 at 09:07

score 4 · Answer 4 · answered Jul 14 '15 at 06:56

4

Worked for me:

XStream xstream = new XStream(new DomDriver("UTF_8", new NoNameCoder()));

answered Jul 14 '15 at 06:56

Nacho Soriano

589
5
15

1

works on 1.4.7 only with `"UTF8"` instead of `"UTF_8"` – Vertex Jul 04 '16 at 13:29

score 0 · Answer 5 · edited Sep 14 '20 at 10:35

0

I used this

XStream xstream = new XStream(new DomDriver("UTF_8", new NoNameCoder()));

It worked but it increases the excution time/ parsing time to 4-5minutes

edited Sep 14 '20 at 10:35

David Buck

3,752
35
31
35

answered Sep 14 '20 at 10:15

Tarun

1

XStream and underscores

5 Answers5

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