When developing a JSF application you may find yourself in situations where it is easier to supply localized text from the backing bean then to use complex JSF expressions in a Facelet. This may also reduce code duplication when conditional behaviour can be reused.
The easiest way to retrieve localized text from one of the resource bundles is to use the javax.faces.application.Application#evaluateExpressionGet method. You can use it in the following way.
package nl.rug.search.odr.util;
import javax.faces.context.FacesContext;
/**
*
* @author Ben Ripkens <bripkens.dev@gmail.com>
*/
public class JsfUtil {
public static <T> T evaluateExpressionGet(String expression, Class<? extends T> expected) {
return JsfUtil.evaluateExpressionGet(FacesContext.getCurrentInstance(), expression, expected);
}
public static <T> T evaluateExpressionGet(FacesContext context, String expression, Class<? extends T> expected) {
return context.getApplication().evaluateExpressionGet(context, expression, expected);
}
}package nl.rug.search.odr.util;
import nl.rug.search.odr.Filename;
import nl.rug.search.odr.SessionAttribute;
/**
*
* @author Ben Ripkens <bripkens.dev@gmail.com>
*/
public abstract class ErrorUtil {
public static void showErrorMessageUsingExpression(String headline, String content) {
headline = JsfUtil.evaluateExpressionGet(headline, String.class);
content = JsfUtil.evaluateExpressionGet(content, String.class);
showErrorMessage(headline, content);
}
public static void showErrorMessage(String headline, String content) {
SessionUtil.addValues(
new String[]{SessionAttribute.ERROR_TITLE, SessionAttribute.ERROR_CONTENT},
new String[]{headline, content});
JsfUtil.redirect(Filename.ERROR_WITH_LEADING_SLASH);
}
public static void showUknownError() {
ErrorUtil.showErrorMessageUsingExpression("#{error['unknown.heading']}",
"#{error['unknown.message']}");
}
// ...
}These code samples are part of the Open Decision Repository project.