logback-android/src/main/java/ch/qos/logback/core/util/OptionHelper.java
public static String getSystemProperty(String key) {
    try {
      String prop = System.getProperty(key);
      return (prop == null) ? getAndroidSystemProperty(key) : prop;
    } catch (SecurityException e) {
      return null;
    }
  }
public static String getSystemProperty(String key) {
    try {
      String prop = System.getProperty(key);
      return (prop == null) ? getAndroidSystemProperty(key) : prop;
    } catch (SecurityException e) {
      return null;
    }
  }
Very similar to <code>System.getProperty</code> except that the
{@link SecurityException} is absorbed. Also checks Android
system properties as a fallback.

@param key The key to search for.
@return the string value of the system property.