We Keep Coding

How to filter Firebase class before putting it into recyclerView

I am using an addChildEventListener on the users level of my firebase database which contains usernames email and latest_post. The recyclerView will only use latest_post which is optional and not all users will have it, so I need to filter the userPosts object so that it contains only the users that have the field `latest_post'. here is the event listener:
query.addChildEventListener(new ChildEventListener() {
#Override
public void onChildAdded(DataSnapshot dataSnapshot, String prevChildKey) {
User userPost = dataSnapshot.getValue(User.class);
System.out.println("User" + userPost.getUsername());
}
This is how I setUp the recyclerView cells:
void setPost(final User user) {
final Post post = user.getLatest_post();
final Long date = post.post_date;
final String post_id = post.getPost_id();
final String key = post.getPost_id();
final Integer reads = post.getReads();
final String titleString = post.getTitle();
final String bodyString = post.getBody();
final String usernameString = post.getAuthor();
final String category = post.getCategory();
final String author_id = post.getAuthor_id();
...
}
So unless I filter userPosts before I setUp the view it will crash because it will try even on the paths where there is no latest_post. How can I filter so that the object I use when setting up the recycler view only contains objects where latest_post is not null? I cannot change the database structure as this point. Thank you.
UPDATE:
By doing this I can see that It knows which values have latest_post and which don't, but im still not sure how to make it into a nice object I can do my setup with. I've updated the code like so:
query.addChildEventListener(new ChildEventListener() {
#Override
public void onChildAdded(DataSnapshot dataSnapshot, String prevChildKey) {
Post latestPost = dataSnapshot.child("latest_post").getValue(Post.class);
Boolean userPost = dataSnapshot.hasChild("latest_post");
System.out.println("User" + userPost);
System.out.println("latestPost" + latestPost);
}
So somehow I can just use the Post class contained in User:
void setPost(final Post post) {
final Post latest = post;
final Long date = latest.post_date;
final String post_id = latest.getPost_id();
final String key = latest.getPost_id();
final Integer reads = latest.getReads();
final String titleString = latest.getTitle();
final String bodyString = latest.getBody();
final String usernameString = latest.getAuthor();
final String category = latest.getCategory();
final String author_id = latest.getAuthor_id();
...
}

After a lot of research, it turns out you can order a query, for example:
query = query.child("users").orderByChild("latest_post")
This would allow the recycled view to work but once you scroll to a certain point, it would crash.
You cannot filter a query to exclude items that don't exist.
I had to create my own recycler adapter, and use a list of my post class, and then filter that list after querying the database.

Java Android Gson convert boolean to int from response server

Help me, guys!
Please, advise a simple solution to convert type boolean from server to int in Android :)
When I log in, i get respone from server like this :
{"status":{"error":0,"code":200,"message":"OK"},"response":{"profile":{"id":114,"username":"k#gmail.com","full_name":"k","phone":"9999999","verified":1,"admin":0,"allow_dev":false,"company":{"id":9,"name":"ООО \"Фингерз медиа\"","email":"info#fingers.by","sample":null,"logo":"http://storage.guardian-glass.fingersmedia.by/0cb56968b3cec1bba301db8d51d1015e.jpg"}},"access_token":"15629e234e04a54a5a44ef2aa4eccb1d"}}
Then I get undefined exception: com.google.gson.JsonSyntaxException: java.lang.IllegalStateException: Expected NUMBER but was BOOLEAN
This happens because of JsonElement "allow_dev" is boolean from server, and in Android I have "allow_dev" like int.
This is login method :
private void login(String email, String pass) {
showProgress();
JsonObject params = new JsonObject();
params.addProperty("username", email);
params.addProperty("password", pass);
UserOperationsTask task = new UserOperationsTask(UserOperationsTask.TaskMode.MODE_LOGIN, params) {
#Override
public void onLoadFinished(Bundle res) {
hideProgress();
String errorMessage = res.getString(UserOperationsTask.RESULT_ERROR_STRING);
if (errorMessage != null) {
showMessage(getString(R.string.login_error), getString(R.string.server_request_error));
} else {
String json = res.getString(UserOperationsTask.RESULT_JSON_STRING);
if (json != null) {
JsonParser parser = new JsonParser();
JsonObject responseData = parser.parse(json).getAsJsonObject();
JsonObject companyObj = responseData.getAsJsonObject("profile").getAsJsonObject("company");
}
setRegisteredMode();
}
}
};
task.execute(this);
}
This method parse response and I tried to convert allow_dev type from boolean to int, but I dont understand whether I'm doing right?
private Bundle parseProfileResponse(Context context, JsonObject responseData) {
Log.d(TAG, "parseProfileResponse");
// I tried convert allow_dev type from boolean to int
String allow_dev_server = String.valueOf(responseData.get("allow_dev"));
boolean b = allow_dev_server.equals("true");
int allow_dev = b ? 1 : 0; // true == 1
Profile profile;
profile = GsonHolder.getGSONInstance().fromJson(responseData.getAsJsonObject("profile"), Profile.class);
profile.allow_dev = allow_dev;
Bundle res = new Bundle();
res.putParcelable(RESULT_OBJ, profile);
res.putString(RESULT_JSON_STRING, responseData.toString());
try {
Cache.saveToCache(context, profile);
} catch (RemoteException e) {
Log.d(TAG, "parseAuthResponse RemoteException: " + e.toString());
res.putString(RESULT_ERROR_STRING, context.getString(R.string.database_error));
} catch (OperationApplicationException e) {
Log.d(TAG, "parseAuthResponse OperationApplicationException: " + e.toString());
res.putString(RESULT_ERROR_STRING, context.getString(R.string.database_error));
}
return res;
}
I have to get "allow_dev" convert it in int and write to database.

If you can switch to mappings, you can use everything static typing can give you, comparing to weakly "typed" JsonElement and its subclasses. It has several advantages: compile-time checking, more robust code, IDE support, etc. The major disadvantage is that you have to write custom mappings, however you there tools (online as well) that can try to generate simple mapping classes based on the given sample JSON (for example, a very popular tool here: http://www.jsonschema2pojo.org/).
Now, let's create some mappings. The mappings like the ones below are used rarely: final fields (used for "server responses" that are no supposed to be modified programmatically; Gson can assign such fields anyway); null for non-primitives and some hacks for primitive type defaults values to cheat the compiler (like Integer.value(0) but not simply 0: otherwise, javac may inline constants, thus Gson cannot affect them); no getters/setters (data-transfer objects are just data bags, but yes, getters can work better). Anyway, you can use your style, and the followings mappings are used for demonstration purposes (the mappings code has even compact formatting: one property per line collapsing the annotations).
final class Response<T> {
final Status status = null;
final T response = null;
}
final class Status {
final int error = Integer.valueOf(0);
final int code = Integer.valueOf(0);
final String message = null;
}
final class ProfileAndAccessToken {
final Profile profile = null;
#SerializedName("access_token") final String accessToken = null;
}
final class Profile {
final int id = Integer.valueOf(0);
final String username = null;
#SerializedName("full_name") final String fullName = null;
final String phone = null;
final int verified = Integer.valueOf(0);
final int admin = Integer.valueOf(0);
#SerializedName("allow_dev") #JsonAdapter(BooleanToIntTypeAdapter.class) final int allowDev = Integer.valueOf(0);
final Company company = null;
}
final class Company {
final int id = Integer.valueOf(0);
final String name = null;
final String email = null;
final String sample = null;
final URL logo = null;
}
Note two annotations above:
#SerializedName -- this annotation can "rename" fields so you can use even special characters (however it's discouraged, and it's typically used to map incoming JSON property names to javaCamelNamingConventions).
#JsonAdapter -- this annotation can "attach" a special type adapter to a certain field, so that it could convert JSON properties to the given field and vice versa.
Now let's implement a type adapter that can convert incoming boolean values to local int values and vice versa. Note that type adapters work in streaming manner, so you have to read JSON tokens stream on fly during read, and, of course, generate JSON tokens stream during write.
final class BooleanToIntTypeAdapter
extends TypeAdapter<Integer> {
// Public constructors may be evil, and let expose as less as possible
// Gson can still instantiate this type adapter itself
private BooleanToIntTypeAdapter() {
}
#Override
#SuppressWarnings("resource")
public void write(final JsonWriter out, final Integer value)
throws IOException {
// If the given value is null, we must write the `null` token to the output JSON tokens stream anyway in order not to break JSON documents
if ( value == null ) {
out.nullValue();
return;
}
// Let's assume that we can accept either 0 or 1 that are mapped to false and true respectively
switch ( value ) {
case 0:
out.value(false);
break;
case 1:
out.value(true);
break;
default:
// Or throw an exception as fast as we can
throw new IllegalArgumentException("Cannot convert " + value + " to a boolean literal");
}
}
#Override
public Integer read(final JsonReader in)
throws IOException {
// Peek the next token type, and if it's null, then return null value too
if ( in.peek() == NULL ) {
return null;
}
// Otherwise parse the next token as boolean and map it either to 1 or 0
return in.nextBoolean() ? 1 : 0;
}
}
That's all you need in Gson. Now, for you entire JSON, since the response mapping class is generic, you have to tell Gson what the T is. Gson accepts java.lang.reflect.Type in the fromJson method, and this type can hold both raw and parameterized types, so Gson could (de)serialize more accurately.
private static final Type profileAndAccessTokenResponse = new TypeToken<Response<ProfileAndAccessToken>>() {
}.getType();
final Response<ProfileAndAccessToken> response = gson.fromJson(JSON, profileAndAccessTokenResponse);
System.out.println(response.response.profile.allowDev);
System.out.println(gson.toJson(response, profileAndAccessTokenResponse));
Output:
0
{"status":{"error":0,"code":200,"message":"OK"},"response":{"profile":{"id":114,"username":"k#gmail.com","full_name":"k","phone":"9999999","verified":1,"admin":0,"allow_dev":false,"company":{"id":9,"name":"ООО \"Фингерз медиа\"","email":"info#fingers.by","logo":"http://storage.guardian-glass.fingersmedia.by/0cb56968b3cec1bba301db8d51d1015e.jpg"}},"access_token":"15629e234e04a54a5a44ef2aa4eccb1d"}}
Note that the first line is 0: this what is generated with BooleanToIntTypeAdapter. Backing to your code:
String allow_dev_server = String.valueOf(responseData.get("allow_dev"));
boolean b = allow_dev_server.equals("true");
int allow_dev = b ? 1 : 0; // true == 1
Profile profile;
profile = GsonHolder.getGSONInstance().fromJson(responseData.getAsJsonObject("profile"), Profile.class);
profile.allow_dev = allow_dev;
Can be replaced with simple:
final Profile profile = GsonHolder.getGSONInstance().fromJson(responseData.getAsJsonObject("profile"), Profile.class)
// now `Profile.allowDev` is 0 or 1 automatically
Note that responseData can be replace with a particular mapping, so you could even not parse at that line: probably you might simply pass the whole response object as a class mapping rather that JsonObject in your parseProfileResponse -- it would be more robust.

Java file encoding magic

Strange thing happened in Java Kingdom...
Long story short: I use Java API V3 to connect to QuickBooks and fetch the data form there (services for example).
Everything goes fine except the case when a service contains russian symbols (or probably non-latin symbols).
Here is Java code that does it (I know it's far from perfect)
package com.mde.test;
import static com.intuit.ipp.query.GenerateQuery.$;
import static com.intuit.ipp.query.GenerateQuery.select;
import java.util.LinkedList;
import java.util.List;
import com.intuit.ipp.core.Context;
import com.intuit.ipp.core.ServiceType;
import com.intuit.ipp.data.Item;
import com.intuit.ipp.exception.FMSException;
import com.intuit.ipp.query.GenerateQuery;
import com.intuit.ipp.security.OAuthAuthorizer;
import com.intuit.ipp.services.DataService;
import com.intuit.ipp.util.Config;
public class TestEncoding {
public static final String QBO_BASE_URL_SANDBOX = "https://sandbox-quickbooks.api.intuit.com/v3/company";
private static String consumerKey = "consumerkeycode";
private static String consumerSecret = "consumersecretcode";
private static String accessToken = "accesstokencode";
private static String accessTokenSecret = "accesstokensecretcode";
private static String appToken = "apptokencode";
private static String companyId = "companyidcode";
private static OAuthAuthorizer oauth = new OAuthAuthorizer(consumerKey, consumerSecret, accessToken, accessTokenSecret);
private static final int PAGING_STEP = 500;
public static void main(String[] args) throws FMSException {
List<Item> res = findAllServices(getDataService());
System.out.println(res.get(1).getName());
}
public static List<Item> findAllServices(DataService service) throws FMSException {
Item item = GenerateQuery.createQueryEntity(Item.class);
List<Item> res = new LinkedList<>();
for (int skip = 0; ; skip += PAGING_STEP) {
String query = select($(item)).skip(skip).take(PAGING_STEP).generate();
List<Item> items = (List<Item>)service.executeQuery(query).getEntities();
if (items.size() > 0)
res.addAll(items);
else
break;
}
System.out.println("All services fetched");
return res;
}
public static DataService getDataService() throws FMSException {
Context context = getContext();
if (context == null) {
System.out.println("Context is null, something wrong, dataService also will null.");
return null;
}
return getDataService(context);
}
private static Context getContext() {
try {
return new Context(oauth, appToken, ServiceType.QBO, companyId);
} catch (FMSException e) {
System.out.println("Context is not loaded");
return null;
}
}
protected static DataService getDataService(Context context) throws FMSException {
DataService service = new DataService(context);
Config.setProperty(Config.BASE_URL_QBO, QBO_BASE_URL_SANDBOX);
return new DataService(context);
}
}
This file is saved in UTF-8. And it prints something like
All services fetched
Сэрвыс, отнюдь
But! When I save this file in UTF-8 with BOM.... I get the correct data!
All services fetched
Сэрвыс, отнюдь
Does anybody can explain what is happening? :)
// I use Eclipse to run the code

You are fetching data from a system that doesn't share the same byte ordering as you, so when you save the file with BOM, it adds enough information in the file that future programs will read it in the remote system's byte ordering.
When you save it without BOM, it wrote the file in the remote system's byte ordering without any indication of the stored byte order, so when you read it you read it with the local system's (different) byte order. This jumbles up the bytes within the multi-byte characters, making the output appear as nonsense.

Image field as part of the FieldGroup in Vaadin7

I have a requirement to display the image as part of the FieldGroup. This is for the functionality where the Image appears as normal on a web page, when in edit mode I need to edit this image value by providing an 'upload' option.
I have a Pojo with a property of type com.vaadin.ui.Image along with the other String and Integer values.
public Image getImage() {
return image;
}
public void setImage(Image image) {
this.image = image;
}
I need to work this Image as a normal form element, for example when I edit a form, I have an editable TextField to type in the String value and change it, the same way I intend to display an upload button where I would have an option to replace the existing image.
I have tried using EasyUploads addon for this purpose by intercepting the build method of FieldGroup and specifying the Image field as of type org.vaadin.easyuploads.UploadField
Like this;
#Override
#SuppressWarnings({ "rawtypes", "unchecked" })
protected <T extends Field> T build(String caption, Class<?> dataType,
Class<T> fieldType) throws BindException {
T field = super.build(caption, dataType, fieldType);
if (caption.equalsIgnoreCase("image")) {
final UploadField imageField = new UploadField() {
#Override
protected void updateDisplay() {
final byte[] pngData = (byte[]) getValue();
String filename = getLastFileName();
String mimeType = getLastMimeType();
long filesize = getLastFileSize();
if (mimeType.equals("image/jpeg")) {
StreamSource imagesource = new ImageSource(pngData);
StreamResource resource = new StreamResource(
imagesource, "Uploaded File");
Embedded embedded = new Embedded("Image:" + filename
+ "(" + filesize + " bytes)", resource);
getRootLayout().addComponent(embedded);
} else {
super.updateDisplay();
}
}
};
imageField.setFieldType(FieldType.BYTE_ARRAY);
...
This however fails to display the already available image, errors out with the stacktrace:
Caused by: java.lang.IllegalArgumentException: Property type class com.vaadin.ui.Image is not compatible with UploadField
at org.vaadin.easyuploads.UploadField.setPropertyDataSource(UploadField.java:1021)
at com.vaadin.data.fieldgroup.FieldGroup.bind(FieldGroup.java:265)
at com.vaadin.data.fieldgroup.BeanFieldGroup.bind(BeanFieldGroup.java:167)
at com.vaadin.data.fieldgroup.FieldGroup.setItemDataSource(FieldGroup.java:106)
at com.vaadin.data.fieldgroup.BeanFieldGroup.setItemDataSource(BeanFieldGroup.java:142)
Is there a cleaner way of using an Image as part of the FieldGroup in vaadin 7?

I would suggest replacing in your Pojo the Image instance with a simple byte[], because looking through the UploadField code, I can't see any natural way of converting the result from the upload (which is either a byte[] or a File instance) into something else, using the FieldGroup like you asked.
If you look inside AbstractField.getValue(), you will see that the model value is eventually passed through a settable converter which would have normally helped you in this case (see com.vaadin.data.util.converter.Converter). But I think you are pretty much forced to use byte[] if you want to bind a image bean to the FieldGroup.
Anyway, if you DO replace with byte[] the following steps will help you:
Create a custom FieldGroupFieldFactory that will create an UploadField if you want to bind to a byte[] property + passes a ValueChangeListener for the UploadField is done uploading:
public class ImageEnhancedFieldFactory extends DefaultFieldGroupFieldFactory {
private Property.ValueChangeListener fileUploadedListener;
private ImageEnhancedFieldFactory(Property.ValueChangeListener fileUploadedListener) {
this.fileUploadedListener = fileUploadedListener;
}
#Override
public <T extends Field> T createField(Class<?> type, Class<T> fieldType) {
if (byte[].class.equals(type)) {
UploadField uploadField = new UploadField(UploadField.StorageMode.MEMORY);
uploadField.setFieldType(UploadField.FieldType.BYTE_ARRAY);
uploadField.setButtonCaption("Change image");
uploadField.addListener(fileUploadedListener);
return (T) uploadField;
}
return super.createField(type, fieldType);
}
}
Create an Image instance that shows the content of the byte[] from the pojo:
final ImagePojo imagePojo = new ImagePojo();
imagePojo.setName("superman");
imagePojo.setImageContent(new byte[0]);
BeanItem<ImagePojo> item = new BeanItem<ImagePojo>(imagePojo);
final StreamResource imageResource = new StreamResource(new StreamResource.StreamSource() {
#Override
public InputStream getStream() {
return new ByteArrayInputStream(imagePojo.getImageContent());
}
}, "myimage");
imageResource.setCacheTime(0);
final Image image = new Image("Image", imageResource);
addComponent(image);
NOTE: its necessary to set the cache time to 0 in order to prevent the browser from caching the resource( see https://vaadin.com/book/vaadin7/-/page/components.embedded.html in the section Generating and Reloading Images)
3.Create the FieldGroup (with the new FieldGroupFieldFactory set) and bind to the properties of the pojo, including the one that contains the image content (the byte[]):
FieldGroup fieldGroup = new FieldGroup(item);
fieldGroup.setFieldFactory(new ImageEnhancedFieldFactory(new Property.ValueChangeListener() {
#Override
public void valueChange(Property.ValueChangeEvent event) {
SimpleDateFormat df = new SimpleDateFormat("yyyyMMddHHmmssSSS");
String filename = "myfilename-" + df.format(new Date()) + ".jpg";
imagePojo.setImageContent((byte[])event.getProperty().getValue());
image.markAsDirty();
imageResource.setFilename(filename);
}
}));
addComponent(fieldGroup.buildAndBind("Image name", "name"));
addComponent(fieldGroup.buildAndBind("Image content", "imageContent"));
I left a snippet on Gist of a component that you can paste in you UI and play around if you need (https://gist.github.com/gabrielruiu/9953279)

How to get profile image url from Facebook with spring-social?

I use spring-social-facebook to interact with Graph API (1.0.3.RELEASE if it's metter). And I can't find any operation to retrieve profile's image url. I found only operations which return array of bytes and they are not very convenient for the implementation.
Does any kind of operation which retrieves image url exist in Spring Social?
If not, is there any 'tidy' workaround for this?
Thanks!

Finally, I didn't find any mention of profile picture url in spring social
My solution:
Initially I planned to extend UserOperations (FacebokTemplate.userOperations) class and add new method. But it's a package-level class and doens't visible outside.
So I decided to create my own template class extending FacebookTemplate and implement the method in this way:
public String fetchPictureUrl(String userId, ImageType imageType) {
URI uri = URIBuilder.fromUri(GRAPH_API_URL + userId + "/picture" +
"?type=" + imageType.toString().toLowerCase() + "&redirect=false").build();
JsonNode response = getRestTemplate().getForObject(uri, JsonNode.class);
return response.get("data").get("url").getTextValue();
}

i just ran into same issue, hope this will help someone else
Connection<Facebook> connection = userConnectionRepository.findPrimaryConnection(Facebook.class);
connection.createData().getImageUrl()

You could take the miniature picture in this way :
"http://graph.facebook.com/" + fbUser.getId() + "/picture?type=square"

In social API you have ability just to fetch the image binary file:
byte[] profileImage = facebook.userOperations().getUserProfileImage(imageType);
To get URL you need to have something custom (as mentioned in the post above).
I took the part of code from Facebook Social API (see Facebook template source code for fetchImage) and the following utility class:
public final class FacebookUtils {
private static final String PICTURE_PATH = "picture";
private static final String TYPE_PARAMETER = "type";
private static final String WIDTH_PARAMETER = "width";
private static final String HEIGHT_PARAMETER = "height";
private FacebookUtils() {
}
public static String getUserProfileImageUrl(Facebook facebook, String userId, String width, String height, ImageType imageType) {
URIBuilder uriBuilder = URIBuilder.fromUri(facebook.getBaseGraphApiUrl() + userId + StringUtils.SLASH_CHARACTER + PICTURE_PATH);
if (imageType != null) {
uriBuilder.queryParam(TYPE_PARAMETER, imageType.toString().toLowerCase());
}
if (width != null) {
uriBuilder.queryParam(WIDTH_PARAMETER, width.toString());
}
if (height != null) {
uriBuilder.queryParam(HEIGHT_PARAMETER, height.toString());
}
URI uri = uriBuilder.build();
return uri.toString();
}
}