JSF 自定义转换器

Question

我有一个这样的自定义转换器：

@Override
public Object getAsObject(FacesContext facesContext, UIComponent component, String str) {
    System.out.println("vadeConverter before getAsObject(" + str);
    SimpleDateFormat dateFormat = new SimpleDateFormat("yyyy-mm-dd");

    String values[] = str.split(":");
    Vade vade = new Vade();
    if (values.length > 1) {
        vade.setId(Integer.parseInt(values[0]));
        vade.setEtiket(values[1]);
        try{
            vade.setTakasTarihi(dateFormat.parse(values[2]));
        }catch (Exception e){
            e.printStackTrace();
        }           
    }
    System.out.println("vadeConverter after getAsObject(" + vade.toString());
    return vade;
}

@Override
public String getAsString(FacesContext context, UIComponent component,
        Object object) {
    Vade vade = (Vade) object;
    String str = "";
    System.out.println("vadeConverter before getAsString(object) -> " + vade.toString());
    if (vade != null) {
        str = vade.getId().toString()+":"+
                vade.getEtiket()+":"+
                vade.getTakasTarihi().toString()
                ;
    }
    System.out.println("vadeConverter after getAsString(object) -> " + str);
    return str;
}

在控制台的输出中是：

vadeConverter before getAsString(object) -> Vade{id=7etiket=T+0takasTarihi=2012-02-21}
vadeConverter after getAsString(object) -> 7:T+0:2012-02-21
vadeConverter before getAsString(object) -> Vade{id=12etiket=T+2takasTarihi=2012-02-27}
vadeConverter after getAsString(object) -> 12:T+2:2012-02-27
vadeConverter before getAsString(object) -> Vade{id=13etiket=T+3takasTarihi=2012-02-28}
vadeConverter after getAsString(object) -> 13:T+3:2012-02-28
vadeConverter before getAsString(object) -> Vade{id=14etiket=T+4takasTarihi=2012-02-29}
vadeConverter after getAsString(object) -> 14:T+4:2012-02-29
vadeConverter before getAsString(object) -> Vade{id=15etiket=T+5takasTarihi=2012-03-01}
vadeConverter after getAsString(object) -> 15:T+5:2012-03-01
vadeConverter before getAsString(object) -> Vade{id=16etiket=T+6takasTarihi=2012-03-02}
vadeConverter after getAsString(object) -> 16:T+6:2012-03-02
vadeConverter before getAsString(object) -> Vade{id=17etiket=T+7takasTarihi=2012-03-03}
vadeConverter after getAsString(object) -> 17:T+7:2012-03-03
vadeConverter before getAsString(object) -> Vade{id=18etiket=T+8takasTarihi=2012-03-04}
vadeConverter after getAsString(object) -> 18:T+8:2012-03-04
vadeConverter before getAsString(object) -> Vade{id=19etiket=T+9takasTarihi=2012-03-05}
vadeConverter after getAsString(object) -> 19:T+9:2012-03-05

当我从控制台的 selectonemenu 中选择一个值时，我得到了这个：

vadeConverter before getAsObject(12:T+2:2012-02-27
vadeConverter after getAsObject(Vade{id=12etiket=T+2takasTarihi=Fri Jan 27 00:02:00 EET 2012}

当然，结果我得到验证错误。我相信我以正确的方式编写转换器，但我不知道这段代码有什么问题..

Answer 1

您使用mm 而不是MM 来表示月份。 mm 代表分钟。请注意，您得到的是 Jan 而不是 Feb 并且您得到的是 2 分钟而不是 0 分钟。您可以找到格式化模式语法in SimpleDateFormat javadoc。

然而，更可靠的是使用getTime() 和new Date(time) 而不是toString() 和SimpleDateFormat#parse()。这样你也不依赖于默认的toString() 结果。