In Java, you can use the Properties class to load and store properties from a file, and the Properties.loadFromXML method to load properties from an XML file. Therefore, to convert an XML file to properties, you can use the Properties.loadFromXML method to read the properties from the XML file, and then store them in a new properties file using the Properties.store method.

Here's an example of how to convert an XML file to properties:

import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.util.Properties;

public class XMLToProperties {
    public static void main(String[] args) {
        // Load properties from XML file
        Properties props = new Properties();
        try (FileInputStream fis = new FileInputStream("myprops.xml")) {
            props.loadFromXML(fis);
        } catch (IOException e) {
            e.printStackTrace();
        }

        // Write properties to file
        try (FileOutputStream fos = new FileOutputStream("myprops.properties")) {
            props.store(fos, "My Properties");
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

In this example, we load properties from an XML file called myprops.xml using the loadFromXML method and store them in a Properties object. We then write the properties to a properties file called myprops.properties using the store method.

The loadFromXML method takes an InputStream that contains the XML data, and reads the properties from the <properties> element in the XML. The store method takes an OutputStream to write the properties to, and a string that represents a comment to include in the properties file. The properties file will contain a key-value pair for each property in the XML file.

Note that the loadFromXML method does not handle escaped characters in property values, so you may need to unescape them manually if they are present in your XML file. Also note that the store method writes the properties in an unspecified order, so the order of properties in the output file may not match the order in the input file.