access build parameter in Jenkins plugin

gistfile1.java

try {
	EnvVars envVars;
	envVars = build.getEnvironment(listener);
	listener.getLogger().println("DEPLOY_ON-DEV: " + envVars.get("DEPLOY_ON_DEV"));
} catch (IOException e1) {
	listener.getLogger().println(e1);
} catch (InterruptedException e1) {
	listener.getLogger().println(e1);
}