CODEWITHSUNDEEP
javaxml-parsingapache-commons
user1448668
user1448668

Reputation: 79

Commons configuration library to add elements

I am using the apache commons configuration library to read a configuration xml and it works nicely. However, I am not able to modify the value of the elements or add new ones.

To read the xml I use the following code:

XMLConfiguration config = new XMLConfiguration(dnsXmlPath);

boolean enabled = config.getBoolean("enabled", true));
int size = config.getInt("size");

To write I am trying to use:

config.setProperty("newProperty", "valueNewProperty");
config.save();

If I call config.getString("newProperty"), I obtain "valueNewProperty", but the xml has not been changed. Obviously it is not the right way or I am missing something, because it does not work. Could anybody tell me how to do this? Thanks in advance.

Upvotes: 1

Views: 453

Answers (2)

Tala
Tala

Reputation: 8928

You're modifying xml structure in memory

The parsed document will be stored keeping its structure. The class also tries to preserve as much information from the loaded XML document as possible, including comments and processing instructions. These will be contained in documents created by the save() methods, too.

Like other file based configuration classes this class maintains the name and path to the loaded configuration file. These properties can be altered using several setter methods, but they are not modified by save() and load() methods. If XML documents contain relative paths to other documents (e.g. to a DTD), these references are resolved based on the path set for this configuration.

You need to use XMLConfiguration.html#save(java.io.Writer) method

For example, after you've done all your modifications save it:

 config.save(new PrintWriter(new File(dnsXmlPath)));

EDIT

As mentioned in comment, calling config.load() before calling setProperty() method fixes the issue.

Upvotes: 2

user1448668
user1448668

Reputation: 79

I solved it with the following lines. I was missing the config.load().

XMLConfiguration config = new XMLConfiguration(dnsXmlPath);
config.load();
config.setProperty("newProperty", "valueNewProperty");
config.save();

It is true though that you can used the next line instead of config.save() and works the same.

config.save(new PrintWriter(new File(dnsXmlPath)));

Upvotes: 0

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