Java tutorial
/** * JBoss, Home of Professional Open Source * Copyright Red Hat, Inc., and individual contributors. * * 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 org.jboss.aerogear.simplepush.protocol.impl.json; import com.fasterxml.jackson.core.JsonGenerator; import com.fasterxml.jackson.core.JsonParser; import com.fasterxml.jackson.core.ObjectCodec; import com.fasterxml.jackson.core.Version; import com.fasterxml.jackson.databind.DeserializationContext; import com.fasterxml.jackson.databind.JsonDeserializer; import com.fasterxml.jackson.databind.JsonNode; import com.fasterxml.jackson.databind.JsonSerializer; import com.fasterxml.jackson.databind.ObjectMapper; import com.fasterxml.jackson.databind.SerializerProvider; import com.fasterxml.jackson.databind.module.SimpleModule; import org.jboss.aerogear.simplepush.protocol.Ack; import org.jboss.aerogear.simplepush.protocol.AckMessage; import org.jboss.aerogear.simplepush.protocol.HelloMessage; import org.jboss.aerogear.simplepush.protocol.HelloResponse; import org.jboss.aerogear.simplepush.protocol.MessageType; import org.jboss.aerogear.simplepush.protocol.NotificationMessage; import org.jboss.aerogear.simplepush.protocol.PingMessage; import org.jboss.aerogear.simplepush.protocol.RegisterMessage; import org.jboss.aerogear.simplepush.protocol.RegisterResponse; import org.jboss.aerogear.simplepush.protocol.UnregisterMessage; import org.jboss.aerogear.simplepush.protocol.UnregisterResponse; import org.jboss.aerogear.simplepush.protocol.impl.AckImpl; import org.jboss.aerogear.simplepush.protocol.impl.AckMessageImpl; import org.jboss.aerogear.simplepush.protocol.impl.HelloMessageImpl; import org.jboss.aerogear.simplepush.protocol.impl.HelloResponseImpl; import org.jboss.aerogear.simplepush.protocol.impl.NotificationMessageImpl; import org.jboss.aerogear.simplepush.protocol.impl.PingMessageImpl; import org.jboss.aerogear.simplepush.protocol.impl.RegisterMessageImpl; import org.jboss.aerogear.simplepush.protocol.impl.RegisterResponseImpl; import org.jboss.aerogear.simplepush.protocol.impl.StatusImpl; import org.jboss.aerogear.simplepush.protocol.impl.UnregisterMessageImpl; import org.jboss.aerogear.simplepush.protocol.impl.UnregisterResponseImpl; import java.io.IOException; import java.io.StringWriter; import java.util.HashSet; import java.util.Set; import java.util.UUID; /** * JSON utility class for transforming SimplePush messages to and from JSON. * */ public final class JsonUtil { private static ObjectMapper om = createObjectMapper(); private static ObjectMapper createObjectMapper() { om = new ObjectMapper(); final SimpleModule module = new SimpleModule("MyModule", new Version(0, 10, 0, null, "org.jboss.aerogear", "aerogear-simplepush-server")); module.addDeserializer(MessageType.class, new MessageTypeDeserializer()); module.addDeserializer(RegisterMessageImpl.class, new RegisterDeserializer()); module.addSerializer(RegisterMessageImpl.class, new RegisterSerializer()); module.addDeserializer(RegisterResponseImpl.class, new RegisterResponseDeserializer()); module.addSerializer(RegisterResponseImpl.class, new RegisterResponseSerializer()); module.addDeserializer(HelloMessageImpl.class, new HelloDeserializer()); module.addSerializer(HelloMessageImpl.class, new HelloSerializer()); module.addDeserializer(HelloResponseImpl.class, new HelloResponseDeserializer()); module.addSerializer(HelloResponseImpl.class, new HelloResponseSerializer()); module.addDeserializer(AckMessageImpl.class, new AckDeserializer()); module.addSerializer(AckMessageImpl.class, new AckSerializer()); module.addDeserializer(PingMessageImpl.class, new PingDeserializer()); module.addSerializer(PingMessageImpl.class, new PingSerializer()); module.addDeserializer(NotificationMessageImpl.class, new NotificationDeserializer()); module.addSerializer(NotificationMessageImpl.class, new NotificationSerializer()); module.addDeserializer(UnregisterMessageImpl.class, new UnregisterDeserializer()); module.addSerializer(UnregisterMessageImpl.class, new UnregisterMessageSerializer()); module.addDeserializer(UnregisterResponseImpl.class, new UnregisterResponseDeserializer()); module.addSerializer(UnregisterResponseImpl.class, new UnregisterResponseSerializer()); om.registerModule(module); return om; } private JsonUtil() { } /** * Transforms from JSON to the type specified. * * @param json the json to be transformed. * @param type the Java type that the JSON should be transformed to. * @return T an instance of the type populated with data from the json message. */ public static <T> T fromJson(final String json, final Class<T> type) { try { return om.readValue(json, type); } catch (final Exception e) { throw new RuntimeException("error trying to parse json [" + json + "]", e); } } /** * Transforms from Java object notation to JSON. * * @param obj the Java object to transform into JSON. * @return {@code String} the json representation for the object. */ public static String toJson(final Object obj) { final StringWriter stringWriter = new StringWriter(); try { om.writeValue(stringWriter, obj); return stringWriter.toString(); } catch (final Exception e) { throw new RuntimeException("error trying to parse json [" + obj + "]", e); } } /** * A convenience method for transforming a SimplePush message frame into an instance * of {@link MessageType}. * * @param json the JSON representing a message in the SimplePush protocol * @return {@link MessageType} an instance of MessageType for the passed in json. */ public static MessageType parseFrame(final String json) { return fromJson(json, MessageType.class); } private static class RegisterDeserializer extends JsonDeserializer<RegisterMessageImpl> { @Override public RegisterMessageImpl deserialize(final JsonParser jp, final DeserializationContext ctxt) throws IOException { final ObjectCodec oc = jp.getCodec(); final JsonNode node = oc.readTree(jp); return new RegisterMessageImpl(node.get(RegisterMessage.CHANNEL_ID_FIELD).asText()); } } private static class RegisterSerializer extends JsonSerializer<RegisterMessage> { @Override public void serialize(final RegisterMessage register, final JsonGenerator jgen, final SerializerProvider provider) throws IOException { jgen.writeStartObject(); jgen.writeFieldName(RegisterMessage.MESSSAGE_TYPE_FIELD); jgen.writeString(register.getMessageType().toString().toLowerCase()); jgen.writeFieldName(RegisterMessage.CHANNEL_ID_FIELD); jgen.writeString(register.getChannelId()); jgen.writeEndObject(); } } private static class RegisterResponseDeserializer extends JsonDeserializer<RegisterResponseImpl> { @Override public RegisterResponseImpl deserialize(final JsonParser jp, final DeserializationContext ctxt) throws IOException { final ObjectCodec oc = jp.getCodec(); final JsonNode node = oc.readTree(jp); return new RegisterResponseImpl(node.get(RegisterMessage.CHANNEL_ID_FIELD).asText(), new StatusImpl(node.get(RegisterResponseImpl.STATUS_FIELD).asInt(), "N/A"), node.get(RegisterResponseImpl.PUSH_ENDPOINT__FIELD).asText()); } } private static class RegisterResponseSerializer extends JsonSerializer<RegisterResponse> { @Override public void serialize(final RegisterResponse registerResponse, final JsonGenerator jgen, final SerializerProvider provider) throws IOException { jgen.writeStartObject(); jgen.writeFieldName(RegisterResponse.MESSSAGE_TYPE_FIELD); jgen.writeString(registerResponse.getMessageType().toString().toLowerCase()); jgen.writeFieldName(RegisterResponse.CHANNEL_ID_FIELD); jgen.writeString(registerResponse.getChannelId()); jgen.writeFieldName(RegisterResponse.STATUS_FIELD); jgen.writeNumber(registerResponse.getStatus().getCode()); jgen.writeFieldName(RegisterResponse.PUSH_ENDPOINT__FIELD); jgen.writeString(registerResponse.getPushEndpoint()); jgen.writeEndObject(); } } private static class HelloDeserializer extends JsonDeserializer<HelloMessageImpl> { @Override public HelloMessageImpl deserialize(final JsonParser jp, final DeserializationContext ctxt) throws IOException { final ObjectCodec oc = jp.getCodec(); final JsonNode node = oc.readTree(jp); final JsonNode channelIdsNode = node.get(HelloMessage.CHANNEL_IDS_FIELD); final Set<String> channelIds = new HashSet<String>(); if (channelIdsNode != null && channelIdsNode.isArray()) { for (JsonNode channelIdNode : channelIdsNode) { channelIds.add(channelIdNode.asText()); } } final JsonNode uaid = node.get(HelloMessage.UAID_FIELD); if (uaid != null) { return new HelloMessageImpl(node.get(HelloMessage.UAID_FIELD).asText(), channelIds); } else { return new HelloMessageImpl(); } } } private static class HelloSerializer extends JsonSerializer<HelloMessage> { @Override public void serialize(final HelloMessage hello, final JsonGenerator jgen, final SerializerProvider provider) throws IOException { jgen.writeStartObject(); jgen.writeFieldName(HelloMessage.MESSSAGE_TYPE_FIELD); jgen.writeString(hello.getMessageType().toString().toLowerCase()); jgen.writeFieldName(HelloMessage.UAID_FIELD); jgen.writeString(hello.getUAID()); jgen.writeArrayFieldStart(HelloMessage.CHANNEL_IDS_FIELD); for (String channelId : hello.getChannelIds()) { jgen.writeString(channelId); } jgen.writeEndArray(); jgen.writeEndObject(); } } private static class HelloResponseDeserializer extends JsonDeserializer<HelloResponseImpl> { @Override public HelloResponseImpl deserialize(final JsonParser jp, final DeserializationContext ctxt) throws IOException { final ObjectCodec oc = jp.getCodec(); final JsonNode node = oc.readTree(jp); final JsonNode uaid = node.get(HelloMessage.UAID_FIELD); return new HelloResponseImpl(UUID.fromString(uaid.asText()).toString()); } } private static class HelloResponseSerializer extends JsonSerializer<HelloResponse> { @Override public void serialize(final HelloResponse helloResponse, final JsonGenerator jgen, final SerializerProvider provider) throws IOException { jgen.writeStartObject(); jgen.writeFieldName(HelloMessage.MESSSAGE_TYPE_FIELD); jgen.writeString(helloResponse.getMessageType().toString().toLowerCase()); jgen.writeFieldName(HelloMessage.UAID_FIELD); jgen.writeString(helloResponse.getUAID()); jgen.writeEndObject(); } } private static class AckDeserializer extends JsonDeserializer<AckMessageImpl> { @Override public AckMessageImpl deserialize(final JsonParser jp, final DeserializationContext ctxt) throws IOException { final ObjectCodec oc = jp.getCodec(); final JsonNode node = oc.readTree(jp); final JsonNode acksNode = node.get(AckMessage.UPDATES_FIELD); final Set<Ack> acks = new HashSet<Ack>(); if (acksNode.isArray()) { for (JsonNode ackNode : acksNode) { acks.add(new AckImpl(ackNode.get("channelID").asText(), ackNode.get("version").asLong())); } } return new AckMessageImpl(acks); } } private static class AckSerializer extends JsonSerializer<AckMessage> { @Override public void serialize(final AckMessage ackMessage, final JsonGenerator jgen, final SerializerProvider provider) throws IOException { jgen.writeStartObject(); jgen.writeFieldName(AckMessage.MESSSAGE_TYPE_FIELD); jgen.writeString(ackMessage.getMessageType().toString().toLowerCase()); jgen.writeArrayFieldStart(AckMessage.UPDATES_FIELD); for (Ack ack : ackMessage.getAcks()) { jgen.writeStartObject(); jgen.writeFieldName("channelID"); jgen.writeString(ack.getChannelId()); jgen.writeFieldName(AckMessage.VERSION_FIELD); jgen.writeNumber(ack.getVersion()); jgen.writeEndObject(); } jgen.writeEndArray(); jgen.writeEndObject(); } } private static class NotificationDeserializer extends JsonDeserializer<NotificationMessageImpl> { @Override public NotificationMessageImpl deserialize(final JsonParser jp, final DeserializationContext ctxt) throws IOException { final ObjectCodec oc = jp.getCodec(); final JsonNode node = oc.readTree(jp); final JsonNode updatesNode = node.get(NotificationMessage.UPDATES_FIELD); final Set<Ack> acks = new HashSet<Ack>(); if (updatesNode.isArray()) { for (JsonNode channelNode : updatesNode) { final JsonNode versionNode = channelNode.get(NotificationMessage.VERSION_FIELD); final JsonNode channelIdNode = channelNode.get(RegisterMessage.CHANNEL_ID_FIELD); acks.add(new AckImpl(channelIdNode.asText(), versionNode.asLong())); } } return new NotificationMessageImpl(acks); } } private static class NotificationSerializer extends JsonSerializer<NotificationMessage> { @Override public void serialize(final NotificationMessage notification, final JsonGenerator jgen, final SerializerProvider provider) throws IOException { jgen.writeStartObject(); jgen.writeFieldName(NotificationMessage.MESSSAGE_TYPE_FIELD); jgen.writeString(notification.getMessageType().toString().toLowerCase()); jgen.writeArrayFieldStart(NotificationMessage.UPDATES_FIELD); for (Ack ack : notification.getAcks()) { jgen.writeStartObject(); jgen.writeFieldName(RegisterMessage.CHANNEL_ID_FIELD); jgen.writeString(ack.getChannelId()); jgen.writeFieldName(NotificationMessage.VERSION_FIELD); jgen.writeNumber(ack.getVersion()); jgen.writeEndObject(); } jgen.writeEndArray(); jgen.writeEndObject(); } } private static class UnregisterDeserializer extends JsonDeserializer<UnregisterMessageImpl> { @Override public UnregisterMessageImpl deserialize(final JsonParser jp, final DeserializationContext ctxt) throws IOException { final ObjectCodec oc = jp.getCodec(); final JsonNode node = oc.readTree(jp); final JsonNode channelIdNode = node.get(RegisterMessage.CHANNEL_ID_FIELD); return new UnregisterMessageImpl(channelIdNode.asText()); } } private static class UnregisterMessageSerializer extends JsonSerializer<UnregisterMessage> { @Override public void serialize(final UnregisterMessage unregister, final JsonGenerator jgen, final SerializerProvider provider) throws IOException { jgen.writeStartObject(); jgen.writeFieldName(UnregisterMessage.MESSSAGE_TYPE_FIELD); jgen.writeString(unregister.getMessageType().toString().toLowerCase()); jgen.writeFieldName(RegisterMessage.CHANNEL_ID_FIELD); jgen.writeString(unregister.getChannelId()); jgen.writeEndObject(); } } private static class MessageTypeDeserializer extends JsonDeserializer<MessageType> { @Override public MessageType deserialize(final JsonParser jp, final DeserializationContext ctxt) throws IOException { final ObjectCodec oc = jp.getCodec(); final JsonNode node = oc.readTree(jp); final JsonNode messageTypeNode = node.get(MessageType.MESSSAGE_TYPE_FIELD); return new MessageType() { @Override public Type getMessageType() { if (messageTypeNode == null) { return MessageType.Type.PING; } return MessageType.Type.valueOf(messageTypeNode.asText().toUpperCase()); } }; } } private static class UnregisterResponseDeserializer extends JsonDeserializer<UnregisterResponseImpl> { @Override public UnregisterResponseImpl deserialize(final JsonParser jp, final DeserializationContext ctxt) throws IOException { final ObjectCodec oc = jp.getCodec(); final JsonNode node = oc.readTree(jp); final JsonNode channelIdNode = node.get(RegisterResponse.CHANNEL_ID_FIELD); return new UnregisterResponseImpl(channelIdNode.asText(), new StatusImpl(node.get(UnregisterResponse.STATUS_FIELD).asInt(), "N/A")); } } private static class UnregisterResponseSerializer extends JsonSerializer<UnregisterResponse> { @Override public void serialize(final UnregisterResponse unregisterResponse, final JsonGenerator jgen, final SerializerProvider provider) throws IOException { jgen.writeStartObject(); jgen.writeFieldName(RegisterResponse.MESSSAGE_TYPE_FIELD); jgen.writeString(unregisterResponse.getMessageType().toString().toLowerCase()); jgen.writeFieldName(RegisterResponse.CHANNEL_ID_FIELD); jgen.writeString(unregisterResponse.getChannelId()); jgen.writeFieldName(RegisterResponse.STATUS_FIELD); jgen.writeNumber(unregisterResponse.getStatus().getCode()); jgen.writeEndObject(); } } private static class PingDeserializer extends JsonDeserializer<PingMessageImpl> { @Override public PingMessageImpl deserialize(final JsonParser jp, final DeserializationContext ctxt) throws IOException { final ObjectCodec oc = jp.getCodec(); final JsonNode node = oc.readTree(jp); if (node.isObject() && node.size() == 0) { return new PingMessageImpl(node.toString()); } throw new RuntimeException("Invalid Ping message format : [" + node.toString() + "]"); } } private static class PingSerializer extends JsonSerializer<PingMessage> { @Override public void serialize(final PingMessage ping, final JsonGenerator jgen, final SerializerProvider provider) throws IOException { jgen.writeStartObject(); jgen.writeEndObject(); } } }