private String getProfileProperties(Properties defaultProperties, String key) {
//        env option support??
//        String envProfile = System.getenv(ACTIVE_PROFILE_KEY);
        String value = javaSystemProperty.getProperty(key);
        if (value == null) {
            value = defaultProperties.getProperty(key);
        }
        return value;
    }
<pre>Configuration order</pre>

<p> Same order as Spring-Boot </p>
<p>
    <a href="https://docs.spring.io/spring-boot/docs/2.1.9.RELEASE/reference/html/boot-features-external-config.html">
        boot-features-external-config
    </a>
</p>
<ol>
    <li>Java System properties</li>
    <li>OS environment variables</li>
    <li>agent external configuration</li>
    <li>agent profile configuration /profiles/${profile}/pinpoint.config</li>
    <li>agent config /pinpoint-env.config</li>
</ol>
agent-module/bootstraps/bootstrap/src/main/java/com/navercorp/pinpoint/bootstrap/config/ProfilePropertyLoader.java