Apache Configurations - Handling Multiple XML entries of same name

Question

All - not sure if I'm on the right track with this or not, but here's what I have so far.

We have a processor that needs to go through and handle a series of files we specify in a config file.

    XMLConfiguration config = new XMLConfiguration(CONFIG_FILE_DIR);

    if (config != null) {
        String filePath = config.getString("files.file.filepath");
        String inputFile = config.getString("files.file.inputfile");
        String outputFile = config.getString("files.file.outputfile");
        String cellRange = config.getString("files.file.cellrange");

        translateXLS(filePath, inputFile, outputFile, cellRange);
    }
    else {
        System.out.println("CONFIG NOT SET");
    }

The translate XLS method works great, and goes ahead and processes whatever file we gave it from a config file.

We have a bit of a problem when we want it to process multiple files though, as it will just simply take the last entry and use that. Obviously I don't have any looping mechanisms or arrays in place so that makes sense, but I am wondering if I need to use XPath or something along those lines to handle a sample config below:

    <xml version="1.0" encoding="UTF-8">
        <files>
            <file>
                <filepath>C:\sample\</filepath>
                <inputfile>1.xls</inputfile>
                <outputfile>1out.out</outputfile>
                <cellrange>F1:I2</cellrange>
            </file>
            <file>
                <filepath>C:\sample\</filepath>
                <inputfile>2.xls</inputfile>
                <outputfile>2out.out</outputfile>
                <cellrange>A1:J2</cellrange>
            </file>
        </files>
    </xml>

What would be the best option for storing something like a list or array of configs to loop through and perform actions on all files within the same config.xml?

I have mainly been using this for a reference. Technically I can set up something like the indexes they use here, but I would have to hard code exactly how many entries I have. It'd be nice if it were flexible enough to just go through every entry.

http://www.code-thrill.com/2012/05/configuration-that-rocks-with-apache.html

Answer 1

You can use JAXB if you don't want to have any external dependencies. JAXB is included in Java 6 and later.

First create a class that represents a <file></file> entry:

public class FileEntry {
    @XmlElement public String filepath;
    @XmlElement public String inputfile;
    @XmlElement public String outputfile;
    @XmlElement public String cellrange;
}

Then create a class representing <files></files>:

public class Config {
    @XmlElement(name="file") public List<FileEntry> entries;
}

Then load the XML:

public static void main(String[] args) throws JAXBException {
    JAXBContext ctx = JAXBContext.newInstance(Config.class);
    Unmarshaller um = ctx.createUnmarshaller();
    JAXBElement<Config> element = um.unmarshal(new StreamSource(new File("config.xml")), Config.class);
    Config config = element.getValue();
    for (FileEntry file : config.entries) {
        System.out.println(file.filepath);
        System.out.println(file.inputfile);
        System.out.println(file.outputfile);
        System.out.println(file.cellrange);
    }
}

And the first line of your xml file should be <?xml version="1.0" encoding="UTF-8"?> and no </xml>at the end.