Java tutorial
/* * Copyright (C) 2014 Toshiaki Maki * * 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 am.ik.categolj2.api.file; import am.ik.categolj2.api.MediaTypeResolver; import org.joda.time.DateTime; import org.springframework.http.HttpHeaders; import org.springframework.http.MediaType; import java.util.concurrent.TimeUnit; public class HttpHeadersBuilder { private final HttpHeaders headers = new HttpHeaders(); private final MediaTypeResolver mediaTypeResolver; public HttpHeadersBuilder(MediaTypeResolver mediaTypeResolver) { this.mediaTypeResolver = mediaTypeResolver; } public HttpHeadersBuilder contentTypeForceAttachment(String fileName) { MediaType mediaType = mediaTypeResolver.resolveFromFilename(fileName); headers.setContentType(mediaType); headers.setContentDispositionFormData("attachment", fileName); return this; } public HttpHeadersBuilder contentTypeAttachmentIfNeccessary(String fileName) { MediaType mediaType = mediaTypeResolver.resolveFromFilename(fileName); headers.setContentType(mediaType); if (MediaType.APPLICATION_OCTET_STREAM.equals(mediaType)) { // set attachment only in case of application/octet-stream headers.setContentDispositionFormData("attachment", fileName); } return this; } public HttpHeadersBuilder cacheForSeconds(int seconds, boolean mustRevalidate) { // HTTP 1.0 header headers.setExpires(System.currentTimeMillis() + TimeUnit.SECONDS.toMillis(seconds)); // HTTP 1.1 header String headerValue = "private, max-age=" + seconds; if (mustRevalidate) { headerValue += ", must-revalidate"; } headers.setCacheControl(headerValue); return this; } public HttpHeadersBuilder preventCaching() { headers.setPragma("no-cache"); // HTTP 1.0 header headers.setExpires(1L); // HTTP 1.1 header: "no-cache" is the standard value, // "no-store" is necessary to prevent caching on FireFox. headers.setCacheControl("no-cache, no-store"); return this; } public HttpHeadersBuilder lastModified(DateTime lastModifiedDate) { headers.setLastModified(lastModifiedDate.getMillis()); return this; } public HttpHeaders build() { return headers; } }