question: public String combine ( List < String > files , String outFile ) throws Exception { ArrayList < String > cmd = new ArrayList < String > ( ) ; cmd . add ( soxBin ) ; for ( String file : files ) { cmd . add ( file ) ; } cmd . add ( outFile ) ; int rc = execSox ( cmd , callback ) ; if ( rc != 0 ) { throw new Exception ( "exit code: " + rc ) ; } return outFile ; }
target:  Simple combiner sox file[0] file[1] ... file[n] <outFile>