viewutils.java

看了《 使用JSF 构建数据库驱动的应用程序》 一文后

package jsfdb.view;

import javax.faces.application.FacesMessage;
import javax.faces.context.FacesContext;
import javax.faces.el.ValueBinding;

import java.util.ResourceBundle;

public class ViewUtils {
    public static Object eval(String expr) {
        FacesContext context= FacesContext.getCurrentInstance();
        ValueBinding binding= context.getApplication().createValueBinding(expr);
        return binding.getValue(context);
    }

    public static void addErrorMessage(FacesContext context,
            String compId, String messageId) {
        ResourceBundle bundle = ResourceBundle.getBundle(
            context.getApplication().getMessageBundle());
        FacesMessage message = new FacesMessage(bundle.getString(messageId));
        message.setSeverity(FacesMessage.SEVERITY_ERROR);
        context.addMessage(compId, message);
    }

    public static void addExceptionMessage(Exception x) {
        FacesContext context  = FacesContext.getCurrentInstance();
        FacesMessage message  = new FacesMessage(x.getMessage());
        message.setSeverity(FacesMessage.SEVERITY_FATAL);
        context.addMessage(null, message);
    }

}