AWS Elastic Beanstalk limits JVM properties to 200 chars, so to get more system properties than that, pack them into the other properties that are supported

PreprocessSystemProperties.java

import java.util.Properties;
import java.util.Enumeration;

public class PreprocessSystemProperties {
  public static void main(String[] args) {
    System.out.println("Before preprocessing");
    print_properties();
    
    String[] property_list = {"PARAM1", "PARAM2", "PARAM3", "PARAM4", "PARAM5"};
    for (String this_property : property_list) {
      System.out.println("Processing: " + this_property);
      preprocess_property(this_property);
    }

    System.out.println("After preprocessing");
    print_properties();
  }

  static void preprocess_property(String property_name) {
    // PARAM1=foo=bar,bar=quux
    String raw_property = System.getProperty(property_name);
    if (raw_property == null) return;
    for (String this_pair : raw_property.split(",")) {
      String[] left_right = this_pair.split("=");
      System.setProperty(left_right[0], left_right[1]);
    }
  }
  
  static void print_properties() {
    Properties systemProperties = System.getProperties();
    Enumeration enuProp = systemProperties.propertyNames();
    while (enuProp.hasMoreElements()) {
      String propertyName = (String) enuProp.nextElement();
      String propertyValue = systemProperties.getProperty(propertyName);
      System.out.println(propertyName + ": " + propertyValue);
    } 
  }
}