Java tutorial
/* * Copyright 2015 Cask Data, Inc. * * 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 co.cask.cdap.gateway.handlers; import co.cask.cdap.common.conf.Constants; import co.cask.cdap.config.Config; import co.cask.cdap.config.ConfigExistsException; import co.cask.cdap.config.ConfigNotFoundException; import co.cask.cdap.config.DashboardStore; import co.cask.http.AbstractHttpHandler; import co.cask.http.HttpResponder; import com.google.common.base.Charsets; import com.google.common.collect.ImmutableMap; import com.google.gson.JsonArray; import com.google.gson.JsonObject; import com.google.gson.JsonParser; import com.google.gson.JsonSyntaxException; import com.google.inject.Inject; import org.jboss.netty.handler.codec.http.HttpRequest; import org.jboss.netty.handler.codec.http.HttpResponseStatus; import org.slf4j.Logger; import org.slf4j.LoggerFactory; import java.util.List; import java.util.Map; import javax.ws.rs.DELETE; import javax.ws.rs.GET; import javax.ws.rs.POST; import javax.ws.rs.PUT; import javax.ws.rs.Path; import javax.ws.rs.PathParam; /** * Dashboard HTTP Handler. */ @Path(Constants.Gateway.API_VERSION_3 + "/namespaces/{namespace-id}/configuration/dashboards") public class DashboardHttpHandler extends AbstractHttpHandler { private static final Logger LOG = LoggerFactory.getLogger(DashboardHttpHandler.class); private static final JsonParser JSON_PARSER = new JsonParser(); private static final String CONFIG_PROPERTY = "config"; private static final String ID = "id"; private final DashboardStore dashboardStore; @Inject public DashboardHttpHandler(DashboardStore dashboardStore) { this.dashboardStore = dashboardStore; } @Path("/") @POST public void create(HttpRequest request, HttpResponder responder, @PathParam("namespace-id") String namespace) throws Exception { String data = request.getContent().toString(Charsets.UTF_8); // Initialize with empty config if no data is sent during creation of the dashboard if (data.equals("")) { data = "{}"; } if (!isValidJSON(data)) { responder.sendJson(HttpResponseStatus.BAD_REQUEST, "Invalid JSON in body"); return; } //Dashboard Config has the following layout: //Config ID = dashboardId (randomUUID) //Config Properties = Map (Key = CONFIG_PROPERTY, value = Serialized JSON string of dashboard configuration) Map<String, String> propMap = ImmutableMap.of(CONFIG_PROPERTY, data); String dashboardId = ""; try { dashboardId = dashboardStore.create(namespace, propMap); Map<String, String> returnMap = ImmutableMap.of(ID, dashboardId); responder.sendJson(HttpResponseStatus.OK, returnMap); } catch (ConfigExistsException e) { responder.sendJson(HttpResponseStatus.BAD_REQUEST, String.format("Dashboard %s already exists", dashboardId)); } } @Path("/") @GET public void list(HttpRequest request, HttpResponder responder, @PathParam("namespace-id") String namespace) throws Exception { JsonArray jsonArray = new JsonArray(); List<Config> configList = dashboardStore.list(namespace); for (Config config : configList) { JsonObject jsonObject = new JsonObject(); jsonObject.addProperty(ID, config.getId()); jsonObject.add(CONFIG_PROPERTY, JSON_PARSER.parse(config.getProperties().get(CONFIG_PROPERTY))); jsonArray.add(jsonObject); } responder.sendJson(HttpResponseStatus.OK, jsonArray); } @Path("/{dashboard-id}") @DELETE public void delete(HttpRequest request, HttpResponder responder, @PathParam("namespace-id") String namespace, @PathParam("dashboard-id") String id) throws Exception { try { dashboardStore.delete(namespace, id); responder.sendStatus(HttpResponseStatus.OK); } catch (ConfigNotFoundException e) { responder.sendString(HttpResponseStatus.NOT_FOUND, "Dashboard not found"); } } @Path("/{dashboard-id}") @GET public void get(HttpRequest request, HttpResponder responder, @PathParam("namespace-id") String namespace, @PathParam("dashboard-id") String id) throws Exception { try { Config dashConfig = dashboardStore.get(namespace, id); JsonObject jsonObject = new JsonObject(); jsonObject.addProperty(ID, id); //Dashboard Config is stored in ConfigStore as serialized JSON string with CONFIG_PROPERTY key. //When we send the data back, we send it as JSON object instead of sending the serialized string. jsonObject.add(CONFIG_PROPERTY, JSON_PARSER.parse(dashConfig.getProperties().get(CONFIG_PROPERTY))); responder.sendJson(HttpResponseStatus.OK, jsonObject); } catch (ConfigNotFoundException e) { responder.sendString(HttpResponseStatus.NOT_FOUND, "Dashboard not found"); } } @Path("/{dashboard-id}") @PUT public void set(HttpRequest request, HttpResponder responder, @PathParam("namespace-id") String namespace, @PathParam("dashboard-id") String id) throws Exception { try { String data = request.getContent().toString(Charsets.UTF_8); if (!isValidJSON(data)) { responder.sendJson(HttpResponseStatus.BAD_REQUEST, "Invalid JSON in body"); return; } Map<String, String> propMap = ImmutableMap.of(CONFIG_PROPERTY, data); dashboardStore.put(namespace, new Config(id, propMap)); responder.sendStatus(HttpResponseStatus.OK); } catch (ConfigNotFoundException e) { responder.sendString(HttpResponseStatus.NOT_FOUND, "Dashboard not found"); } } private boolean isValidJSON(String json) { try { JSON_PARSER.parse(json); } catch (JsonSyntaxException ex) { return false; } return true; } }