com.thruzero.common.jsf.utils.FacesUtils.java Source code

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Here is the source code for com.thruzero.common.jsf.utils.FacesUtils.java

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/*
 *   Copyright 2011-2012 George Norman
 *
 *   Licensed under the Apache License, Version 2.0 (the "License");
 *   you may not use this file except in compliance with the License.
 *   You may obtain a copy of the License at
 *
 *       http://www.apache.org/licenses/LICENSE-2.0
 *
 *   Unless required by applicable law or agreed to in writing, software
 *   distributed under the License is distributed on an "AS IS" BASIS,
 *   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *   See the License for the specific language governing permissions and
 *   limitations under the License.
 */
package com.thruzero.common.jsf.utils;

import java.io.File;
import java.io.Serializable;

import javax.el.ExpressionFactory;
import javax.el.ValueExpression;
import javax.faces.application.NavigationHandler;
import javax.faces.context.ExternalContext;
import javax.faces.context.FacesContext;
import javax.servlet.ServletContext;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;

import org.apache.commons.lang3.StringUtils;

/**
 * Static utility methods pertaining to JSF.
 *
 * @author George Norman
 */
public class FacesUtils {
    public static final String REDIRECT_URL = "redirectUrl";

    /**
     * Calls handleNavigation on the application's current NavigationHandler.
     *
     * @see javax.faces.application.NavigationHandler.handleNavigation(javax.faces.context.FacesContext, java.lang.String, java.lang.String)
     */
    public static void handleNavigation(String fromAction, String outcome) {
        FacesContext facesContext = FacesContext.getCurrentInstance();
        NavigationHandler navigationHandler = facesContext.getApplication().getNavigationHandler();

        navigationHandler.handleNavigation(facesContext, fromAction, outcome);
    }

    public static HttpServletRequest getRequest() {
        return (HttpServletRequest) getExternalContext().getRequest();
    }

    public static HttpServletResponse getResponse() {
        return (HttpServletResponse) getExternalContext().getResponse();
    }

    /**
     * Return the current valid session associated with this request, if create is false or, if necessary, creates a new
     * session for the request, if create is true.
     */
    public static HttpSession getSession(boolean create) {
        FacesContext facesContext = FacesContext.getCurrentInstance();

        return (HttpSession) facesContext.getExternalContext().getSession(create);
    }

    /** Return the named request header, or null if it doesn't exist. */
    public static String getRequestHeader(String name) {
        return getRequest().getHeader(name);
    }

    public static String getServletContextName() {
        ServletContext ServletContext = (ServletContext) getExternalContext().getContext();

        return ServletContext.getServletContextName();
    }

    public static String getUrlWithContextName(String url) {
        return "/" + getServletContextName() + url;
    }

    public static File getWebInfDir() {
        File webAppPath = new File(getExternalContext().getRealPath("/"));
        String warDeployPath = webAppPath.getAbsolutePath();
        if (StringUtils.isEmpty(warDeployPath)) {
            return null;
        }

        File webInfDir = new File(warDeployPath, "WEB-INF");
        if (webInfDir.exists() && webInfDir.isDirectory()) {
            return webInfDir;
        }

        return null;
    }

    public static Serializable locateManagedBean(String name) {
        Serializable result = (Serializable) getExpressionValue("#{" + name + "}", Serializable.class);

        return result;
    }

    private static Object getExpressionValue(String el, Class<?> cls) {
        FacesContext facesContext = FacesContext.getCurrentInstance();
        ExpressionFactory expressionFactory = facesContext.getApplication().getExpressionFactory();
        ValueExpression valueExpression = expressionFactory.createValueExpression(facesContext.getELContext(), el,
                cls);

        Object result = valueExpression.getValue(facesContext.getELContext());

        return result;
    }

    public static ExternalContext getExternalContext() {
        return FacesContext.getCurrentInstance().getExternalContext();
    }
}