com.qwazr.webapps.StaticResourceServlet Maven / Gradle / Ivy

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Web application server for QWAZR
There is a newer version: 1.5.0
/*
 * Copyright 2015-2016 Emmanuel Keller / QWAZR
 * 
 * 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.qwazr.webapps;

import org.apache.commons.io.IOUtils;

import javax.activation.MimetypesFileTypeMap;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.InputStream;
import java.util.Objects;

public class StaticResourceServlet extends HttpServlet {

	private final String resourcePrefix;

	private final MimetypesFileTypeMap mimeTypeMap;

	public StaticResourceServlet(final String resourcePrefix, final MimetypesFileTypeMap mimeTypeMap) {
		this.resourcePrefix = resourcePrefix;
		this.mimeTypeMap = Objects.requireNonNull(mimeTypeMap, "The mimeTypeMap is missing");
	}

	private String getResourcePath(final HttpServletRequest request) {
		final String path = request.getPathInfo();
		return path == null ? resourcePrefix : resourcePrefix + path;
	}

	private InputStream findResource(final String resourcePath) throws IOException {
		final InputStream input = StaticResourceServlet.class.getResourceAsStream(resourcePath);
		if (input == null)
			throw new FileNotFoundException("File not found: " + resourcePath);
		return input;
	}

	@Override
	final protected void doHead(final HttpServletRequest request, final HttpServletResponse response)
			throws IOException {
		final String resourcePath = getResourcePath(request);
		try (final InputStream input = findResource(resourcePath)) {
			final String type = mimeTypeMap.getContentType(resourcePath);
			StaticFileServlet.head(null, type, null, response);
		} catch (FileNotFoundException e) {
			response.sendError(404, e.getMessage());
		}
	}

	@Override
	final protected void doGet(final HttpServletRequest request, final HttpServletResponse response)
			throws IOException {
		final String resourcePath = getResourcePath(request);
		try (final InputStream input = findResource(resourcePath)) {
			final String type = mimeTypeMap.getContentType(resourcePath);
			StaticFileServlet.head(null, type, null, response);
			IOUtils.copy(input, response.getOutputStream());
		} catch (FileNotFoundException e) {
			response.sendError(404, e.getMessage());
		}
	}
}