今天開發的測試的時候碰到一個問題，就是用Myfaces的SelectOneRadio空間的時候，頁面第一次展現沒問題，當我使用上一步切換tab再下一步的時候就拋出了異常，異常如下：

Caused by: javax.faces.convert.ConverterException: java.lang.ClassCastException: org.apache.myfaces.shared_impl.renderkit.RendererUtils$1

cannot be cast to java.lang.Boolean

at javax.faces.convert.BooleanConverter.getAsString(BooleanConverter.java:91)

at org.apache.myfaces.shared_impl.renderkit.RendererUtils.getConvertedStringValue(RendererUtils.java:630)

at org.apache.myfaces.shared_impl.renderkit.html.HtmlRadioRendererBase.encodeEnd(HtmlRadioRendererBase.java:91)

at javax.faces.component.UIComponentBase.encodeEnd(UIComponentBase.java:624)

... 110 more

Caused by: java.lang.ClassCastException: org.apache.myfaces.shared_impl.renderkit.RendererUtils$1

cannot be cast to java.lang.Boolean

at javax.faces.convert.BooleanConverter.getAsString(BooleanConverter.java:87)

... 113 more



后來在國外網站上面找到了問題所在：



Hello,



the problem still exists in MyFaces Core 1.2.6.



I have a selectOneMenu with a value binding to a boolean property.



In the boolean converter the ClassCastException still occurs.



...

Caused by: javax.faces.convert.ConverterException: java.lang.ClassCastException: org.apache.myfaces.shared_impl.renderkit.RendererUtils$1

cannot be cast to java.lang.Boolean

at javax.faces.convert.BooleanConverter.getAsString(BooleanConverter.java:91)

at org.apache.myfaces.shared_impl.renderkit.RendererUtils.getConvertedStringValue(RendererUtils.java:630)

at org.apache.myfaces.shared_impl.renderkit.html.HtmlRadioRendererBase.encodeEnd(HtmlRadioRendererBase.java:91)

at javax.faces.component.UIComponentBase.encodeEnd(UIComponentBase.java:624)

... 110 more

Caused by: java.lang.ClassCastException: org.apache.myfaces.shared_impl.renderkit.RendererUtils$1

cannot be cast to java.lang.Boolean

at javax.faces.convert.BooleanConverter.getAsString(BooleanConverter.java:87)

... 113 more



In RendererUtils there are some tests that value equals NOTHING. However the equals method

of the NOTHING-Serializable isn't overriden. Therefore it has no effect.



Overriding the equals method as in the patch of paul works.





有些東西沒有實現，導致了這個問題。這個可能需要你自己簡單實現一下源文件然后編譯成庫文件了，感覺麻煩就換成了SelectOneMenu了。

后面有時間再看了

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