Java tutorial
/* * Copyright 2014 Artem Chikin * Copyright 2014 Artem Herasymchuk * Copyright 2014 Tom Krywitsky * Copyright 2014 Henry Pabst * Copyright 2014 Bradley Simons * * 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 ca.ualberta.cmput301w14t08.geochan.json; import java.io.ByteArrayOutputStream; import java.lang.reflect.Type; import java.util.ArrayList; import java.util.Arrays; import java.util.Date; import java.util.List; import android.graphics.Bitmap; import android.graphics.BitmapFactory; import android.util.Base64; import ca.ualberta.cmput301w14t08.geochan.helpers.GsonHelper; import ca.ualberta.cmput301w14t08.geochan.models.Comment; import ca.ualberta.cmput301w14t08.geochan.models.GeoLocation; import ca.ualberta.cmput301w14t08.geochan.models.ThreadComment; import com.google.gson.JsonArray; import com.google.gson.JsonDeserializationContext; import com.google.gson.JsonDeserializer; import com.google.gson.JsonElement; import com.google.gson.JsonObject; import com.google.gson.JsonParseException; import com.google.gson.JsonParser; import com.google.gson.JsonSerializationContext; import com.google.gson.JsonSerializer; /** * Handles the serialization of a ThreadComment object into JSON format for * offline caching. * * @author Artem Chikin * @author Artem Herasymchuk */ public class ThreadCommentOfflineJsonConverter implements JsonSerializer<ThreadComment>, JsonDeserializer<ThreadComment> { /* * (non-Javadoc) * * @see com.google.gson.JsonSerializer#serialize(java.lang.Object, * java.lang.reflect.Type, com.google.gson.JsonSerializationContext) */ /** * Serializes a ThreadComment object into JSON format. * * @param thread The ThreadComment to serialize. * @param type The Type. * @param context The JsonSerializationContext * * @return A JsonElement representing the serialized ThreadComment. */ @Override public JsonElement serialize(ThreadComment thread, Type type, JsonSerializationContext context) { JsonObject object = new JsonObject(); object.addProperty("title", thread.getTitle()); object.addProperty("threadDate", thread.getThreadDate().getTime()); object.addProperty("hasImage", thread.getBodyComment().hasImage()); object.addProperty("id", thread.getId()); if (thread.getBodyComment().getLocation() != null) { object.addProperty("location", thread.getBodyComment().getLocation().getLatitude() + "," + thread.getBodyComment().getLocation().getLongitude()); if (thread.getBodyComment().getLocation().getLocationDescription() != null) { object.addProperty("locationDescription", thread.getBodyComment().getLocation().getLocationDescription()); } } else { object.addProperty("location", "-999,-999"); } object.addProperty("user", thread.getBodyComment().getUser()); object.addProperty("hash", thread.getBodyComment().getHash()); object.addProperty("textPost", thread.getBodyComment().getTextPost()); if (thread.getBodyComment().hasImage()) { Bitmap bitmapThumb = thread.getBodyComment().getImageThumb(); /* * http://stackoverflow.com/questions/9224056/android-bitmap-to-base64 * -string */ ByteArrayOutputStream byteArrayOutputStream = new ByteArrayOutputStream(); bitmapThumb.compress(Bitmap.CompressFormat.JPEG, 90, byteArrayOutputStream); byte[] byteThumbArray = byteArrayOutputStream.toByteArray(); String encodedThumb = Base64.encodeToString(byteThumbArray, Base64.NO_WRAP); object.addProperty("imageThumbnail", encodedThumb); } recursiveSerialize(object, thread.getBodyComment(), thread.getBodyComment().getChildren()); // Serialize all the images in the thread. return object; } /** * Deserializes a ThreadComment object from JSON format. * * @param json The JsonElement to deserialize. * @param type The Type. * @param context The JsonDeserializationContext. * * @return The deserialized ThreadComment. */ @Override public ThreadComment deserialize(JsonElement json, Type type, JsonDeserializationContext context) throws JsonParseException { JsonObject object = json.getAsJsonObject(); String title = object.get("title").getAsString(); long threadDate = object.get("threadDate").getAsLong(); boolean hasImage = object.get("hasImage").getAsBoolean(); String locationString = object.get("location").getAsString(); List<String> locationEntries = Arrays.asList(locationString.split(",")); double latitude = Double.parseDouble(locationEntries.get(0)); double longitude = Double.parseDouble(locationEntries.get(1)); String user = object.get("user").getAsString(); String hash = object.get("hash").getAsString(); String id = object.get("id").getAsString(); String textPost = object.get("textPost").getAsString(); String locationDescription = null; if (object.get("locationDescription") != null) { locationDescription = object.get("locationDescription").getAsString(); } ArrayList<Comment> topList = new ArrayList<Comment>(); recursiveDeserialize(object, id, topList); Bitmap thumbnail = null; if (hasImage) { /* * http://stackoverflow.com/questions/20594833/convert-byte-array-or- * bitmap-to-picture */ String encodedThumb = object.get("imageThumbnail").getAsString(); byte[] thumbArray = Base64.decode(encodedThumb, Base64.NO_WRAP); thumbnail = BitmapFactory.decodeByteArray(thumbArray, 0, thumbArray.length); } GeoLocation location = new GeoLocation(latitude, longitude); location.setLocationDescription(locationDescription); final Comment c = new Comment(textPost, null, location, null); c.getCommentDate().setTime(threadDate); c.setUser(user); c.setHash(hash); c.setId(Long.parseLong(id)); c.setChildren(topList); if (hasImage) { c.setImageThumb(thumbnail); } final ThreadComment comment = new ThreadComment(c, title); comment.setThreadDate(new Date(threadDate)); comment.setId(Long.parseLong(id)); return comment; } private void recursiveSerialize(JsonObject object, Comment parent, ArrayList<Comment> list) { object.addProperty(parent.getId(), GsonHelper.getOfflineGson().toJson(list)); for (Comment comment : list) { recursiveSerialize(object, comment, comment.getChildren()); } } private void recursiveDeserialize(JsonObject object, String id, ArrayList<Comment> list) { JsonParser parser = new JsonParser(); JsonArray array = parser.parse(object.get(id).getAsString()).getAsJsonArray(); for (int i = 0; i < array.size(); ++i) { list.add(GsonHelper.getOfflineGson().fromJson(array.get(i), Comment.class)); } for (Comment comment : list) { ArrayList<Comment> childList = new ArrayList<Comment>(); recursiveDeserialize(object, comment.getId(), childList); comment.setChildren(childList); } } }