JAVA中，对象成员变量的获取的相关问题。（高手请进）

Question

private static ExcMsg[] changeSort(ExcMsg[] msg, String param, final int sort)
        throws Exception {
        final Field f = ExcMsg.class.getField(param);
        java.util.Arrays.sort(msg, new Comparator() {
            public int compare(Object o1, Object o2) {
                if(o1 instanceof ExcMsg && o2 instanceof ExcMsg) {
                    ExcMsg m1 = (ExcMsg)o1;
                    ExcMsg m2 = (ExcMsg)o2;
                    try {
                        if(f.get(m1) instanceof Comparable) {
                            return ((int)Math.pow(-1, sort)) * ((Comparable)f.get(m1)).compareTo(f.get(m2));
                        } else {
                            return 0;
                        }
                    } catch(Exception ee) {}
                }
                return 0;
            }            public boolean equals(Object obj) {
                return false;
            }
        });        return msg;
    }