How to read comma separated properties with apache common configuration in java?

In Apache Commons Configuration, there is PropertiesConfiguration. It supports the feature of converting delimited string to array/list.

For example, if you have a properties file

#Foo.properties
foo=bar1, bar2, bar3

With the below code:

PropertiesConfiguration config = new PropertiesConfiguration("Foo.properties");
String[] values = config.getStringArray("foo");

will give you a string array of ["bar1", "bar2", "bar3"]

---

getString only returns the first value for a multi-value key. Try getStringArray to get both values.

Full Code Example:

ApacheCommonPropertyConfig.java

import java.util.List;

import org.apache.commons.configuration.ConfigurationException;
import org.apache.commons.configuration.PropertiesConfiguration;

public class ApacheCommonPropertyConfig {

    public static void main(String[] args) throws ConfigurationException {
        PropertiesConfiguration config;
        try {
            config = new PropertiesConfiguration("F://foo.properties");
            // For Array
            String[] values = config.getStringArray("foo");
            for(String strVal : values) {
                System.out.println("Array Value is: "+strVal);
            }
            // For List
            List<Object> linclude =  config.getList("foo");
            for(Object str : linclude){
                System.out.println("List Value is: "+str.toString());
            }
            // For List Another
            List<Object> list = config.getList("listOfValue", config.getList("foo"));
            for(Object str : list){
                System.out.println("Another List Value is: "+str.toString());
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}

foo.properties

foo=bar1, bar2, bar3

Output:

Array Value is: bar1
Array Value is: bar2
Array Value is: bar3
List Value is: bar1
List Value is: bar2
List Value is: bar3
Another List Value is: bar1
Another List Value is: bar2
Another List Value is: bar3

---

---

Another example using AbstractFileConfiguration

ListDelimiterDemo.java

import org.apache.commons.configuration.AbstractFileConfiguration;
import org.apache.commons.configuration.ConfigurationException;
import org.apache.commons.configuration.PropertiesConfiguration;


public class ListDelimiterDemo {

    public static void main(String[] args) throws ConfigurationException {
        AbstractFileConfiguration config = new PropertiesConfiguration();
        config.setListDelimiter(',');
        config.load("F://foo.properties");

        for (Object listItem : config.getList("foo")) {
            System.out.println(listItem);
        }
    }
}

Output:

bar1
bar2
bar3

Resource Link:

1. Reading a List from properties file and load with spring annotation @Value
2. Class PropertiesConfiguration

Original Link: Read comma separated properties with configuration2 in java