public FileExtFilter(String[] exts,String description){
  this.exts=new String[exts.length];
  System.arraycopy(exts,0,this.exts,0,exts.length);
  this.description=description;
}

public FileExtFilter ( String [ ] exts , String description ) { this . exts = new String [ exts . length ] ; System . arraycopy ( exts , 0 , this . exts , 0 , exts . length ) ; this . description = description ; }
construct a fileextfilter for a set of related file extension .
