Java tutorial
/** * Copyright (c) Codice Foundation * * <p>This 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 any later version. * * <p>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 Lesser General Public License for more details. A copy of the GNU Lesser General Public * License is distributed along with this program and can be found at * <http://www.gnu.org/licenses/lgpl.html>. */ package org.codice.ddf.transformer.preview; import ddf.catalog.data.BinaryContent; import ddf.catalog.data.Metacard; import ddf.catalog.data.impl.BinaryContentImpl; import ddf.catalog.data.types.experimental.Extracted; import ddf.catalog.transform.CatalogTransformerException; import ddf.catalog.transform.MetacardTransformer; import java.io.Serializable; import java.util.Map; import org.apache.commons.text.StringEscapeUtils; import org.apache.tika.io.IOUtils; public class PreviewMetacardTransformer implements MetacardTransformer { @Override public BinaryContent transform(Metacard metacard, Map<String, Serializable> arguments) throws CatalogTransformerException { if (metacard == null) { throw new CatalogTransformerException("Cannot transform null metacard."); } String preview = "No preview text available."; if (metacard.getAttribute(Extracted.EXTRACTED_TEXT) != null && metacard.getAttribute(Extracted.EXTRACTED_TEXT).getValue() != null) { preview = StringEscapeUtils .escapeHtml4(metacard.getAttribute(Extracted.EXTRACTED_TEXT).getValue().toString()) .replaceAll("[\n|\r]", "<br>"); preview = String.format("<head><meta charset=\"utf-8\"/>%s</head>", preview); } return new BinaryContentImpl(IOUtils.toInputStream(preview)); } }