Trim String in JSF h:outputText value - jsf

Question

Is there any way to string JSF h:outPutTextValue ? my string is A-B-A03 ,i just want to display last 3 characters .does openfaces have any avialable function to do this ?
Thanks

Answer 1

You could use a Converter for this job. JSF has several builtin converters, but no one suits this very specific functional requirement, so you'd need to create a custom one.
It's relatively easy, just implement the Converter interface according its contract:
public class MyConverter implements Converter {
#Override
public String getAsString(FacesContext context, UIComponent component, Object modelValue) throws ConverterException {
// Write code here which converts the model value to display value.
}
#Override
public Object getAsObject(FacesContext context, UIComponent component, String submittedValue) throws ConverterException {
// Write code here which converts the submitted value to model value.
// This method won't be used in h:outputText, but in UIInput components only.
}
}
Provided that you're using JSF 2.0 (your question history confirms this), you can use the #FacesConverter annotation to register the converter. You can use the (default) value attribute to assign it a converter ID:
#FacesConverter("somethingConverter")
(where "something" should represent the specific name of the model value you're trying to convert, e.g. "zipcode" or whatever it is)
so that you can reference it as follows:
<h:outputText value="#{bean.something}" converter="somethingConverter" />
For your particular functional requirement the converter implementation can look like this (assuming that you actually want to split on - and return only the last part, which makes so much more sense than "display last 3 characters"):
#FacesConverter("somethingConverter")
public class SomethingConverter implements Converter {
#Override
public String getAsString(FacesContext context, UIComponent component, Object modelValue) throws ConverterException {
if (!(modelValue instanceof String)) {
return modelValue; // Or throw ConverterException, your choice.
}
String[] parts = ((String) modelValue).split("\\-");
return parts[parts.length - 1];
}
#Override
public Object getAsObject(FacesContext context, UIComponent component, String submittedValue) throws ConverterException {
throw new UnsupportedOperationException("Not implemented");
}
}

Answer 2

You can try and use the fn:substring functions from JSTL:
${fn:substring('A-B-A03', 4, 7)}

Answer 3

If your string comes from a bean you can add an extra getter to return the trimmed version:
private String myString = "A-B-A03";
public String getMyStringTrimmed()
{
// You could also use java.lang.String.substring with some ifs here
return org.apache.commons.lang.StringUtils.substring(myString, -3);
}
Now you can use the getter in your JSF page:
<h:outputText value="#{myBean.myStringTrimmed}"/>