tapestry一个方法中从一个页面向不同页面的跳转问题

public abstract YearSelect getYearSelect();
public abstract QuarterSelect getQuarterSelect();
public abstract YeaeSelectView getYeaeSelectView();
public abstract QuarterSelectView getQuarterSelectView();

public void onCancel(IRequestCycle cycle) {

if(getDirectNO()!=null&&getDirectNO().equals("YearSelect")){

throw new RedirectException(((MyEngine)this.getEngine()).getExternalLinkUrl("YearSelect", null));

} //IRequestCycle
else  if(getDirectNO()!=null&&getDirectNO().equals("YeaeSelectView")){

YeaeSelectView resultPage =(YeaeSelectView)cycle.getPage("YeaeSelectView");
resultPage.setTheYear(getTheYear());
cycle.activate(resultPage);
}
else  if(getDirectNO()!=null&&getDirectNO().equals("QuarterSelect")){

throw new RedirectException(((MyEngine) this.getEngine())
.getExternalLinkUrl("QuarterSelect", null));

}
else {

QuarterSelectView resultPage =(QuarterSelectView)cycle.getPage("QuarterSelectView");

resultPage.setTheYear(getTheYear());
if(getQuarter().equals("up")){
resultPage.setTheQuqrter("上半年");

}
else

resultPage.setTheQuqrter("下半年");
cycle.activate(resultPage);

}

}