How to use

substituteWithProperties

method

in

com.cloudhopper.commons.util.StringUtil

/**
 * Searches the string for occurrences of the pattern $ENV{key} and
 * attempts to replace this pattern with a value from the System environment
 * obtained using the 'key'.  For example, including "$ENV{USERNAME}" in
 * a string and calling this method would then attempt to replace the entire
 * pattern with the value of the environment variable "USERNAME". The System
 * environment is obtained in Java with a call to System.getenv().  An environment variable is typically
 * defined in the Linux shell or Windows property tabs.  NOTE: A Java System
 * property is not the same as an environment variable.
 * @param string0 The string to perform substitution on such as "Hello $ENV{USERNAME}".
 *      This string may be null, empty, or contain one or more substitutions.
 * @return A string with all occurrences of keys substituted with their
 *      values obtained from the System environment.  Can be null if the
 *      original string was null.
 * @throws SubstitutionException Thrown if a starting string was found, but the
 *      ending string was not.  Also, thrown if a key value was empty such
 *      as using "$ENV{}".  Finally, thrown if the property key was not
 *      found in the properties object (could not be replaced).
 * @see #substituteWithProperties(java.lang.String, java.lang.String, java.lang.String, java.util.Properties) 
 */
public static String substituteWithEnvironment(String string0) throws SubstitutionException {
  // turn environment into properties
  Properties envProps = new Properties();
  // add all system environment vars to the properties
  envProps.putAll(System.getenv());
  // delegate to other method using the default syntax $ENV{<key>}
  return substituteWithProperties(string0, "$ENV{", "}", envProps);
}

/**
 * Searches the string for occurrences of the pattern $ENV{key} and
 * attempts to replace this pattern with a value from the System environment
 * obtained using the 'key'.  For example, including "$ENV{USERNAME}" in
 * a string and calling this method would then attempt to replace the entire
 * pattern with the value of the environment variable "USERNAME". The System
 * environment is obtained in Java with a call to System.getenv().  An environment variable is typically
 * defined in the Linux shell or Windows property tabs.  NOTE: A Java System
 * property is not the same as an environment variable.
 * @param string0 The string to perform substitution on such as "Hello $ENV{USERNAME}".
 *      This string may be null, empty, or contain one or more substitutions.
 * @return A string with all occurrences of keys substituted with their
 *      values obtained from the System environment.  Can be null if the
 *      original string was null.
 * @throws SubstitutionException Thrown if a starting string was found, but the
 *      ending string was not.  Also, thrown if a key value was empty such
 *      as using "$ENV{}".  Finally, thrown if the property key was not
 *      found in the properties object (could not be replaced).
 * @see #substituteWithProperties(java.lang.String, java.lang.String, java.lang.String, java.util.Properties) 
 */
public static String substituteWithEnvironment(String string0) throws SubstitutionException {
  // turn environment into properties
  Properties envProps = new Properties();
  // add all system environment vars to the properties
  envProps.putAll(System.getenv());
  // delegate to other method using the default syntax $ENV{<key>}
  return substituteWithProperties(string0, "$ENV{", "}", envProps);
}

/**
 * Creates an InputStream containing the document resulting from replacing template
 * parameters in the given InputStream source.
 * @param source The source stream
 * @param props The properties
 * @param startStr The String that marks the start of a replacement key such as "${"
 * @param endStr The String that marks the end of a replacement key such as "}"
 * @return An InputStream containing the resulting document.
 */
static public InputStream replaceProperties(InputStream source, Properties props, String startStr, String endStr) throws IOException, SubstitutionException {
String template = streamToString(source);
String replaced = StringUtil.substituteWithProperties(template, startStr, endStr, props);
System.err.println(template);
System.err.println(replaced);
return new ByteArrayInputStream(replaced.getBytes());
}