com.semanticcms.core.servlet.ServletElementContext Maven / Gradle / Ivy

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/*
 * semanticcms-core-servlet - Java API for modeling web page content and relationships in a Servlet environment.
 * Copyright (C) 2015, 2016  AO Industries, Inc.
 *     [email protected]
 *     7262 Bull Pen Cir
 *     Mobile, AL 36695
 *
 * This file is part of semanticcms-core-servlet.
 *
 * semanticcms-core-servlet is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Lesser General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * semanticcms-core-servlet 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 Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with semanticcms-core-servlet.  If not, see .
 */
package com.semanticcms.core.servlet;

import com.aoindustries.lang.NotImplementedException;
import com.aoindustries.servlet.http.Dispatcher;
import com.semanticcms.core.model.ElementContext;
import java.io.IOException;
import java.io.PrintWriter;
import java.io.Writer;
import java.util.Map;
import javax.servlet.ServletContext;
import javax.servlet.ServletException;
import javax.servlet.ServletOutputStream;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpServletResponseWrapper;
import javax.servlet.jsp.SkipPageException;

/**
 * An ElementContext that is a ServletContext.
 */
public class ServletElementContext implements ElementContext {

	private final ServletContext servletContext;
	private final HttpServletRequest request;
	private final HttpServletResponse response;

	public ServletElementContext(
		ServletContext servletContext,
		HttpServletRequest request,
		HttpServletResponse response
	) {
		this.servletContext = servletContext;
		this.request = request;
		this.response = response;
	}

	@Override
	public void include(final String resource, Writer out, final Map args) throws IOException, ServletException, SkipPageException {
		final PrintWriter pw;
		if(out instanceof PrintWriter) pw = (PrintWriter)out;
		else pw = new PrintWriter(out);
		// Clear PageContext on include
		PageContext.newPageContext(
			null,
			null,
			null,
			// Java 1.8: Lambda
			new PageContext.PageContextCallable() {
				@Override
				public void call() throws ServletException, IOException, SkipPageException {
					Dispatcher.include(
						servletContext,
						resource,
						request,
						new HttpServletResponseWrapper(response) {
							@Override
							public PrintWriter getWriter() {
								return pw;
							}
							@Override
							public ServletOutputStream getOutputStream() {
								throw new NotImplementedException();
							}
						},
						args
					);
				}
			}
		);
		if(pw.checkError()) throw new IOException("Error on include PrintWriter");
	}
}