it.scoppelletti.wui.HeadTag.java Source code

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Here is the source code for it.scoppelletti.wui.HeadTag.java

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/*
 * Copyright (C) 2012 Dario Scoppelletti, <http://www.scoppelletti.it/>.
 * 
 * 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 it.scoppelletti.wui;

import java.io.*;
import java.net.*;
import java.util.*;
import javax.servlet.jsp.*;
import javax.servlet.jsp.tagext.*;
import org.restlet.data.*;
import org.restlet.representation.*;
import org.restlet.resource.*;
import org.slf4j.*;
import org.springframework.context.*;
import org.springframework.web.context.support.*;
import org.springframework.web.util.*;
import it.scoppelletti.programmerpower.io.*;
import it.scoppelletti.programmerpower.web.rest.*;
import it.scoppelletti.programmerpower.wui.*;

/**
 * Emette il contributo di tutte le applicazioni all&rsquo;elemento
 * <CODE>&lt;head&gt;</CODE> delle pagine.
 */
public final class HeadTag extends SimpleTagSupport {
    private static final Logger myLogger = LoggerFactory.getLogger(HeadTag.class);

    /**
     * Percorso della risorsa REST che rappresenta il contributo di 
     * un&rsquo;applicazione all&rsquo;elemento <CODE>&lt;head&gt;</CODE> delle
     * pagine. Il valore della costante &egrave; <CODE>{@value}</CODE>.
     */
    public static final String HEAD_PATH = "/rest/head";

    /**
     * Percorso della risorsa incorporata che rappresenta il contributo di 
     * un&rsquo;applicazione all&rsquo;elemento <CODE>&lt;head&gt;</CODE> delle
     * pagine. Il valore della costante &egrave; <CODE>{@value}</CODE>.
     */
    public static final String HEAD_RES = "WEB-INF/it-scoppelletti-head.html";

    /**
     * Costruttore.
     */
    public HeadTag() {
    }

    /**
     * Implementazione.
     */
    @Override
    public void doTag() throws IOException, JspException {
        URI uri;
        UriComponentsBuilder uriBuilder;
        WebApplicationManager applMgr;
        List<String> applList;
        ApplicationContext applCtx;
        PageContext pageCtx = (PageContext) getJspContext();

        applCtx = WebApplicationContextUtils.getRequiredWebApplicationContext(pageCtx.getServletContext());

        applMgr = applCtx.getBean(WebApplicationManager.BEAN_NAME, WebApplicationManager.class);
        applList = applMgr.listRunningApplications();

        for (String ctxPath : applList) {
            uriBuilder = UriComponentsBuilder.fromHttpUrl(applMgr.getBaseUrl());
            uriBuilder.path(ctxPath).path(HeadTag.HEAD_PATH);
            uriBuilder.queryParam(AbstractServerResource.QUERY_LOCALE, pageCtx.getRequest().getLocale().toString());
            uri = uriBuilder.build().toUri();

            try {
                head(uri, pageCtx.getOut());
            } catch (Exception ex) {
                myLogger.error(String.format("Failed to get %1$s.", uri), ex);
            }
        }
    }

    /**
     * Emette il contributo di un&rsquo;applicazione all&rsquo;elemento
     * <CODE>&lt;head&gt;</CODE>.
     * 
     * @param uri    Risorsa REST.
     * @param writer Flusso di scrittura.
     */
    private void head(URI uri, JspWriter writer) throws IOException {
        String line;
        ClientResource clientRes;
        Representation rep;
        InputStream in = null;
        Reader reader = null;
        BufferedReader lineReader = null;

        clientRes = new ClientResource(uri);
        rep = clientRes.get(MediaType.TEXT_HTML);
        if (rep == null) {
            return;
        }

        try {
            in = rep.getStream();
            reader = new InputStreamReader(in);
            in = null;
            lineReader = new BufferedReader(reader);
            reader = null;

            line = lineReader.readLine();
            while (line != null) {
                writer.println(line);
                line = lineReader.readLine();
            }
        } finally {
            if (in != null) {
                IOUtils.close(in);
                in = null;
            }
            if (reader != null) {
                IOUtils.close(reader);
                reader = null;
            }
            if (lineReader != null) {
                IOUtils.close(lineReader);
                lineReader = null;
            }
        }
    }
}