Java PropertiesFileReader Utility Class

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This post gives you PropertiesFileReader utility class to use in your Java/Java EE projects. You can use this PropertiesFileReader utility class to load "config.properties" file and it provides getValue() API to retrieve a property value by key. 

This is a common task for a developer to maintain project configuration data or settings in an external file, for example keeping JDBC database configurations or mail configurations in the config.properties file. 

You may be interested in Java Read and Write Properties File Example.

PropertiesFileReader.java

import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.InputStream;
import java.util.Properties;

/**
 * @author Ramesh Fadatare
 *
 */
public class PropertiesFileReader {
    private static Properties prop = null;
    private static final String propFileName = "config.properties";

    private static void loadPropValues() throws IOException {
        prop = new Properties();
        InputStream inputStream = PropertiesFileReader.class.getClassLoader().getResourceAsStream(propFileName);
        prop.load(inputStream);
        if (inputStream == null) {
            throw new FileNotFoundException("property file '" + propFileName + "' not found in the classpath");
        }
    }

    public static String getValue(String key) throws IOException {
        if (prop == null) {
            loadPropValues();
        }
        return prop.getProperty(key);
    }

    public static String getValue(String key, String defaultvalue) throws IOException {
        if (prop == null) {
            loadPropValues();
        }
        return prop.getProperty(key, defaultvalue);
    }
}