Map < String , String > function ( ) { return environment ; }
returns the system environment variables of the process . if the underlying system does not support environment variables , an empty map is returned . the returned map does not accept queries using null keys or values , or those of a type other than string . attempts to pass in a null value will throw a nullpointerexception . types other than string throw a classcastexception . as the returned map is generated using data from the underlying platform , it may not comply with the equals and hashcode contracts . it is also likely that the keys of this map will be case-sensitive . modification of the map is reliant on the underlying platform ; some may not allow any changes to the environment variables or may prevent certain values being used . attempts to do so will throw an unsupportedoperationexception or illegalargumentexception , respectively . use of this method may require a security check for the runtimepermission `` getenv . '' . concode_field_sep Map<String,String> environment concode_elem_sep boolean redirect concode_elem_sep File directory concode_elem_sep List<String> command concode_field_sep Process start concode_elem_sep File directory concode_elem_sep ProcessBuilder directory concode_elem_sep boolean redirectErrorStream concode_elem_sep ProcessBuilder redirectErrorStream concode_elem_sep List<String> command concode_elem_sep ProcessBuilder command concode_elem_sep ProcessBuilder command