Java tutorial
/** * Copyright (C) cedarsoft GmbH. * * Licensed under the GNU General Public License version 3 (the "License") * with Classpath Exception; you may not use this file except in compliance * with the License. You may obtain a copy of the License at * * http://www.cedarsoft.org/gpl3ce * (GPL 3 with Classpath Exception) * * This code is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License version 3 only, as * published by the Free Software Foundation. cedarsoft GmbH designates this * particular file as subject to the "Classpath" exception as provided * by cedarsoft GmbH in the LICENSE file that accompanied this code. * * This code 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 * version 3 for more details (a copy is included in the LICENSE file that * accompanied this code). * * You should have received a copy of the GNU General Public License version * 3 along with this work; if not, write to the Free Software Foundation, * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. * * Please contact cedarsoft GmbH, 72810 Gomaringen, Germany, * or visit www.cedarsoft.com if you need additional information or * have any questions. */ package com.cedarsoft.serialization.serializers.jackson; import com.cedarsoft.serialization.jackson.JacksonParserWrapper; import com.cedarsoft.version.Version; import com.cedarsoft.version.VersionException; import com.cedarsoft.version.VersionRange; import com.cedarsoft.license.CreativeCommonsLicense; import com.cedarsoft.license.License; import com.cedarsoft.serialization.jackson.AbstractJacksonSerializer; import com.fasterxml.jackson.core.JsonGenerator; import com.fasterxml.jackson.core.JsonParseException; import com.fasterxml.jackson.core.JsonParser; import com.fasterxml.jackson.core.JsonProcessingException; import com.fasterxml.jackson.core.JsonToken; import javax.annotation.Nullable; import javax.annotation.Nonnull; import javax.inject.Inject; import java.io.IOException; import java.net.URL; public class LicenseSerializer extends AbstractJacksonSerializer<License> { public static final String PROPERTY_ID = "id"; public static final String PROPERTY_NAME = "name"; public static final String PROPERTY_URL = "url"; public static final String SUB_TYPE_CC = "cc"; @Inject public LicenseSerializer() { super("license", VersionRange.from(1, 0, 0).to(1, 0, 0)); } @Override public void serialize(@Nonnull JsonGenerator serializeTo, @Nonnull License object, @Nonnull Version formatVersion) throws IOException, JsonProcessingException { verifyVersionReadable(formatVersion); if (object instanceof CreativeCommonsLicense) { serializeTo.writeStringField(PROPERTY_SUB_TYPE, SUB_TYPE_CC); } //id serializeTo.writeStringField(PROPERTY_ID, object.getId()); //name serializeTo.writeStringField(PROPERTY_NAME, object.getName()); //URL serializeTo.writeFieldName(PROPERTY_URL); URL url = object.getUrl(); if (url == null) { serializeTo.writeNull(); } else { serializeTo.writeString(url.toString()); } } @Nonnull @Override public License deserialize(@Nonnull JsonParser deserializeFrom, @Nonnull Version formatVersion) throws VersionException, IOException, JsonProcessingException { //If there is a subtype it *must* be cc JacksonParserWrapper parserWrapper = new JacksonParserWrapper(deserializeFrom); parserWrapper.nextToken(); parserWrapper.verifyCurrentToken(JsonToken.FIELD_NAME); if (deserializeFrom.getCurrentName().equals(PROPERTY_SUB_TYPE)) { parserWrapper.nextToken(); parserWrapper.verifyCurrentToken(JsonToken.VALUE_STRING); String subType = deserializeFrom.getText(); if (!subType.equals(SUB_TYPE_CC)) { throw new IllegalStateException("Invalid sub type: " + subType); } parserWrapper.nextToken(); parserWrapper.verifyCurrentToken(JsonToken.FIELD_NAME); String currentName = parserWrapper.getCurrentName(); if (!PROPERTY_ID.equals(currentName)) { throw new JsonParseException( "Invalid field. Expected <" + PROPERTY_ID + "> but was <" + currentName + ">", parserWrapper.getCurrentLocation()); } } //id assert deserializeFrom.getCurrentName().equals(PROPERTY_ID); parserWrapper.nextToken(); parserWrapper.verifyCurrentToken(JsonToken.VALUE_STRING); String id = deserializeFrom.getText(); //name parserWrapper.nextToken(); parserWrapper.verifyCurrentToken(JsonToken.FIELD_NAME); String currentName1 = parserWrapper.getCurrentName(); if (!PROPERTY_NAME.equals(currentName1)) { throw new JsonParseException( "Invalid field. Expected <" + PROPERTY_NAME + "> but was <" + currentName1 + ">", parserWrapper.getCurrentLocation()); } parserWrapper.nextToken(); String name = deserializeFrom.getText(); //url parserWrapper.nextToken(); parserWrapper.verifyCurrentToken(JsonToken.FIELD_NAME); String currentName = parserWrapper.getCurrentName(); if (!PROPERTY_URL.equals(currentName)) { throw new JsonParseException( "Invalid field. Expected <" + PROPERTY_URL + "> but was <" + currentName + ">", parserWrapper.getCurrentLocation()); } JsonToken token = deserializeFrom.nextToken(); @Nullable URL url; if (token == JsonToken.VALUE_NULL) { url = null; } else { url = new URL(deserializeFrom.getText()); } //Finally closing element parserWrapper.nextToken(JsonToken.END_OBJECT); //Constructing the deserialized object try { return License.get(id); } catch (IllegalArgumentException ignore) { return new License(id, name, url); } } }