Custom Variables in JSF Converter's Error Message

问题

I have a form page that has an inputText field that accepts a date. We have a converter that converts the string from the textbox into a Date object (ie. "2011-03-01" to java.util.Date("2011-03-01"") )

If the string is not a date, like "123" then a validation error message will be displayed like "value (123) must be a date".

Currently, in my .properties file, I see:

javax.faces.converter.DateTimeConverter.DATE=value ({0}) must be a date

I need to make this error message more clear by specifying exactly which field must be a date. (As there could be more than one date text fields on the form).

I would like to change it to something like:

javax.faces.converter.DateTimeConverter.DATE=The field "{0}" with value ({1}) must be a date

However, I am unsure how JSF automatically fills in the {0} and {1}. How do I specify my own variables inside the JSF Converter error message?

Note: I have added tried creating my own validator (not to be confused with converter) but it seems that the JSF framework does conversion before validation in its lifecycle.

回答1:

Starting from JSF 1.2, use the converterMessage attribute to replace the entire message, such as:

<h:inputText value="#{user.dateOfBirth}" converterMessage="Format must be: yyyy-MM-dd">
    <f:convertDateTime pattern="yyyy-MM-dd" />
</h:inputText>

Otherwise, JSF by default shows the _detail message in the <h:message>. Only when you use <h:message showDetail="false" showSummary="true"> then the one similar as in your question will be displayed. I'm not sure what JSF version you're using, but in my JSF 2.0.3 the default detail message for f:convertDateTime is the following:

javax.faces.converter.DateTimeConverter.DATE_detail = {2}: ''{0}'' could not be understood as a date. Example: {1}

The {2} will be substituted with the client ID or the label attribute of the input field when present.

<h:inputText value="#{user.dateOfBirth}" label="Date of birth">
    <f:convertDateTime pattern="yyyy-MM-dd" />
</h:inputText>

Both the DATE and DATE_detail message must be defined for the DATE_detail message to be used:

javax.faces.converter.DateTimeConverter.DATE=Date format must be: dd/mm/yyyy 
javax.faces.converter.DateTimeConverter.DATE_detail=Date format must be: dd/mm/yyyy