PrimeFaces extensions - empty value attribute

问题

On my page, I have <pe:inputNumber> which refers to a not mandatory field. If I leave it empty, it sets the value to 0 even if I set emptyValue = "". What should I do or what should I use, if this component cannot offer me that functionality?

回答1:

You might need to specifically instruct JSF to interpret empty input fields as null as against coercing it to "0" with the context-param

<context-param>
    <param-name>javax.faces.INTERPRET_EMPTY_STRING_SUBMITTED_VALUES_AS_NULL</param-name>
    <param-value>true</param-value>
</context-param>

Additionally, for a container built on tomcat (JBoss, WSphere etc), you should set the following JVM config property (pretty easy to do within an IDE)

-Dorg.apache.el.parser.COERCE_TO_ZERO=false

来源：https://stackoverflow.com/questions/14607439/primefaces-extensions-empty-value-attribute