private void setTypeRef ( Configuration conf ) { String className = conf . get ( CLASS_CONF_KEY ) ; if ( className == null ) { throw new RuntimeException ( CLASS_CONF_KEY + " is not set" ) ; } Class < ? > clazz = null ; try { clazz = conf . getClassByName ( className ) ; } catch ( ClassNotFoundException e ) { throw new RuntimeException ( "failed to instantiate class '" + className + "'" , e ) ; } typeRef = new TypeRef < M > ( clazz ) { } ; }
set typeRef from conf