TemplateUtils.java

/*
 * GovWay - A customizable API Gateway 
 * https://govway.org
 * 
 * Copyright (c) 2005-2025 Link.it srl (https://link.it). 
 * 
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 3, as published by
 * the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 *
 */

package org.openspcoop2.utils.resources;

import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.IOException;
import java.io.OutputStreamWriter;
import java.util.Map;

import org.apache.commons.io.input.CharSequenceReader;

import freemarker.cache.TemplateLoader;
import freemarker.template.Configuration;
import freemarker.template.ObjectWrapper;
import freemarker.template.Template;
import freemarker.template.TemplateException;

/**
 *  TemplateUtils
 *
 * @author Poli Andrea (apoli@link.it)
 * @author $Author$
 * @version $Rev$, $Date$
 */
public class TemplateUtils {

    
    /** -------- Utility per la creazione delle configurazioni ------------- */
    
    public static Configuration newTemplateEngine() {
        return TemplateUtils.newTemplateEngine(TemplateUtils.class,"", null,null);
    }
    public static Configuration newTemplateEngine(String prefix) {
        return TemplateUtils.newTemplateEngine(TemplateUtils.class,prefix, null,null);
    }
    public static Configuration newTemplateEngine(Class<?> c) {
        return TemplateUtils.newTemplateEngine(c,"", null,null);
    }
    public static Configuration newTemplateEngine(Class<?> c,String prefix) {
        return TemplateUtils.newTemplateEngine(c, prefix, null,null);
    }
    public static Configuration newTemplateEngine(Class<?> c,String prefix,ObjectWrapper wrapper) {
        return TemplateUtils.newTemplateEngine(c, prefix, wrapper, null);
    }
    public static Configuration newTemplateEngine(Class<?> c,String prefix,ObjectWrapper wrapper,TemplateLoader templateLoader) {
        // Initialize the FreeMarker configuration;
        // - Create a configuration instance
        Configuration cfgFreeMarker = new Configuration(Configuration.VERSION_2_3_23);
        
        cfgFreeMarker.setClassForTemplateLoading(c, prefix);
        
        if(wrapper!=null){
            cfgFreeMarker.setObjectWrapper(wrapper);
        }
        
        if(templateLoader!=null){
            cfgFreeMarker.setTemplateLoader(templateLoader);
        }
        
        return cfgFreeMarker;
    }
    
    
    
    /** -------- Utility per la creazione dei template ------------- */
    
    public static Template getTemplate(Configuration cfg,String templateName) throws IOException{
        return cfg.getTemplate(templateName);
    }
    
    public static Template getTemplate(String templateName) throws IOException{
        Configuration cfg = TemplateUtils.newTemplateEngine();
        return cfg.getTemplate(templateName);
    }
    public static Template getTemplate(String prefix,String templateName) throws IOException{
        Configuration cfg = TemplateUtils.newTemplateEngine(prefix);
        return cfg.getTemplate(templateName);
    }
    public static Template getTemplate(Class<?> c,String prefix,String templateName) throws IOException{
        Configuration cfg = TemplateUtils.newTemplateEngine(c,prefix);
        return cfg.getTemplate(templateName);
    }
    public static Template getTemplate(Class<?> c,String prefix,ObjectWrapper wrapper,String templateName) throws IOException{
        Configuration cfg = TemplateUtils.newTemplateEngine(c,prefix,wrapper);
        return cfg.getTemplate(templateName);
    }
    
    public static Template buildTemplate(String name,byte[] bytes) throws IOException{
        return new Template(name, new CharSequenceReader(new String(bytes)),newTemplateEngine());
    }
    public static Template buildTemplate(Configuration cfg,String name,byte[] bytes) throws IOException{
        return new Template(name, new CharSequenceReader(new String(bytes)),cfg);
    }
    
    
    
    /** -------- Trasformazioni dei template ------------- */
        
    public static byte[] toByteArray(Template template,Map<?, ?> map) throws IOException,TemplateException{
        ByteArrayOutputStream bout = new ByteArrayOutputStream();
        OutputStreamWriter writer = new OutputStreamWriter(bout);
        template.process(map, writer);
        writer.flush();
        writer.close();
        bout.flush();
        bout.close();
        return bout.toByteArray();
    }
    public static String toString(Template template,Map<?, ?> map) throws IOException,TemplateException{
        ByteArrayOutputStream bout = new ByteArrayOutputStream();
        OutputStreamWriter writer = new OutputStreamWriter(bout);
        template.process(map, writer);
        writer.flush();
        writer.close();
        bout.flush();
        bout.close();
        return bout.toString();
    }
    public static void writeFile(Template template,Map<?, ?> map,File file,boolean overwrite) throws Exception{
        if(!overwrite){
            if(file.exists()){
                System.out.println(": WARNING !! File ["+file.getAbsolutePath()+"] is already exist, it is not overwritten !!");
                return;
            }
        }
        FileSystemUtilities.mkdirParentDirectory(file);
        FileSystemUtilities.writeFile(file, TemplateUtils.toByteArray(template, map));
    }
    

    
}