Java tutorial
/** * Copyright (C) 2010-2016 Structr GmbH * * This file is part of Structr <http://structr.org>. * * Structr is free software: you can redistribute it and/or modify * it under the terms of the GNU Affero General Public License as * published by the Free Software Foundation, either version 3 of the * License, or (at your option) any later version. * * Structr 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 Affero General Public License for more details. * * You should have received a copy of the GNU Affero General Public License * along with Structr. If not, see <http://www.gnu.org/licenses/>. */ package org.structr.function; import com.google.gson.Gson; import com.google.gson.GsonBuilder; import com.google.gson.reflect.TypeToken; import java.util.LinkedList; import java.util.List; import java.util.Map; import org.apache.commons.lang3.StringUtils; import org.structr.core.GraphObject; import org.structr.core.GraphObjectMap; import org.structr.schema.action.ActionContext; /** * */ public class FromJsonFunction extends UiFunction { public static final String ERROR_MESSAGE_FROM_JSON = "Usage: ${from_json(src)}. Example: ${from_json('{name:test}')}"; public static final String ERROR_MESSAGE_FROM_JSON_JS = "Usage: ${{Structr.from_json(src)}}. Example: ${{Structr.from_json('{name:test}')}}"; @Override public String getName() { return "from_json()"; } @Override public Object apply(ActionContext ctx, final GraphObject entity, final Object[] sources) { if (sources != null && sources.length > 0) { if (sources[0] != null) { try { final String source = sources[0].toString(); final Gson gson = new GsonBuilder().create(); List<Map<String, Object>> objects = new LinkedList<>(); if (StringUtils.startsWith(source, "[")) { final List<Map<String, Object>> list = gson.fromJson(source, new TypeToken<List<Map<String, Object>>>() { }.getType()); final List<GraphObjectMap> elements = new LinkedList<>(); if (list != null) { objects.addAll(list); } for (final Map<String, Object> src : objects) { final GraphObjectMap destination = new GraphObjectMap(); elements.add(destination); recursivelyConvertMapToGraphObjectMap(destination, src, 0); } return elements; } else if (StringUtils.startsWith(source, "{")) { final Map<String, Object> value = gson.fromJson(source, new TypeToken<Map<String, Object>>() { }.getType()); final GraphObjectMap destination = new GraphObjectMap(); if (value != null) { recursivelyConvertMapToGraphObjectMap(destination, value, 0); } return destination; } } catch (Throwable t) { t.printStackTrace(); } } return ""; } return usage(ctx.isJavaScriptContext()); } @Override public String usage(boolean inJavaScriptContext) { return (inJavaScriptContext ? ERROR_MESSAGE_FROM_JSON_JS : ERROR_MESSAGE_FROM_JSON); } @Override public String shortDescription() { return "Parses the given JSON string and returns an object"; } }