Coding the GIF Service

Our next order of business is to go the service for GIFs. 0:00 Let's start though on the controller, in particular, let's head to the controller 0:03 method that processes the new GIF submission and that is the add GIF method. 0:07 One quick note about a nice feature in IntelliJ and 0:11 other popular IDEs have this as well. 0:14 I have this Structure view, as opposed to the Project view in IntelliJ and 0:16 even if the files not open, with it highlighted, I can click structure. 0:21 And see a quick overview of that class and I mentioned the addGif method. 0:25 So if i double click on that, 0:31 that file opens with the cursor placed directly in the method I just clicked on. 0:33 Pretty cool. 0:38 Now, in order to capture the file data upon upload will need to add 0:40 a MultipartFile parameter to this method. 0:44 MultipartFile right there, I'll name it file. 0:47 And to tell Spring that this is a value that will be passed via the HTTP request 0:54 as a parameter in the payload we'll annotate it with the request param 0:59 annotation. 1:03 @RequestParam just like that and 1:05 this annotation definitely offers a name attribute. 1:09 You can specify a value for the name in there, 1:15 if the name coming from the HTML form differs from that of the parameter name. 1:18 But if I leave this off, this parameter name will be used by default. 1:24 So I'll leave it there because I know in my HTML form. 1:30 I used file as the name attribute on that input element. 1:33 So cool, we now have access to the file data. 1:39 The work we have left to do is to code a GIF service and 1:42 GIF TAO to handle the savings that we can call upon the service from the controller 1:46 to save the uploaded GIF. 1:50 Then, we'll return to this controller to wrap up its code for uploading. 1:52 Let's start by creating the GIF service. 1:57 So I'll go back to my project view. 1:59 And in the service package, I'll create a gif service 2:01 as an interface, GifService. 2:06 Let's add methods in here that we can use to do the same sorts of things that we did 2:13 in the category service. 2:17 So we'll add findAll, findByID, save and delete methods. 2:18 Here we go. 2:23 We'll make the findAll return a list of GIF objects, 2:24 Make sure you import all that stuff. 2:31 Let's import this with option enter, 2:37 there we go, also import the list interface java.util. 2:41 It's not always the first choice as you can see. 2:45 Cool, next, I will return a single GIF object with 2:48 the findByID method which accepts a long parameter value. 2:52 And then my save method will accept two parameter values, 2:58 a GIF and a multi-part file parameter. 3:04 And then, I will include a delete method as well. 3:08 Excellent, now I notice how I added this MultipartFile parameter to the save method 3:13 instead of using only a GIF parameter. 3:18 This is because currently our GIF entity does not include the MultipartFile 3:21 data our controller will have received. 3:25 So will let the service combine the two and I'll show you 3:27 the fairly brief code that's required to make this happen in just a bit. 3:30 Now, let's create the implementation class for this and annotate it with service. 3:35 So I will create a new Java Class, call it GifService. 3:40 This is the implementation i'll name it Impl and 3:45 let's annotate that with Service. 3:50 Next, I'll implement the GIF service interface. 3:53 Implements, GIF service. 3:57 And I'll add all of those unimplemented methods. 4:00 Let's use Option, Implement methods. 4:05 All of those that are not currently included, cool. 4:09 Now just as we did for the category service simple we'll auto wire a DAO 4:12 here but this time it's a gif DAO. 4:16 So we'll do @Autowired. 4:18 Private GifDao gifDao. 4:23 Now we're coding in the reverse order as we did with the categories so 4:27 this DAO is right here gifDao does not exist yet. 4:31 No worries though. 4:34 We'll add it in just a bit. 4:35 Let's finish our work here first. 4:37 So in the find all method, we'll simply call upon the find all method from the DAO 4:39 which we'll code in just a bit. 4:43 So gifdao.findAll. 4:45 And next, in the find by ID method, 4:49 we'll call upon an identical method in the DAO was well, 4:52 gifDao.findById and will pass along that ID parameter value. 4:56 Now let's jump to the delete method and 5:01 do the same before returning to the save method. 5:04 So here we'll just do gifDao.delete Gif. 5:07 Now, back to that save method. 5:14 I said we'd have the service put together this multi-part file data and 5:17 the GIF entity, before persisting the GIF entity. 5:21 To do this, we'll use the gif's setBytes method and 5:24 pass the bytes from the getBytes method of that multipart file parameter. 5:28 Here's what i mean. 5:34 We'll say, gif, that's the entity we'd receive, .setBytes, 5:35 there's the setter that came from our entity. 5:38 And the bytes that we wanna use come from the file, specifically file.getBytes. 5:41 You'll notice here that you're going to either have to make this method throw 5:49 the java.io.IOException here. 5:52 Or you're gonna have to surround it with a try catch. 5:56 Let's go ahead and surround it with a try catch here. 5:59 So I will surround with a try catch. 6:02 Cool and right here, 6:05 all says' instead of printing the stack trace all do system.arrow.print one. 6:07 And I’ll say, unable to get byte array from uploaded file. 6:13 And now that the GIF object will contain everything it needs to persist it's dated 6:21 to the database. 6:24 After that called a set bytes here, let's call the DAOs save method. 6:25 So gitDao.save(gif). 6:31 All right, that's it for the service. 6:36 Next, we'll tackle the DAO and that will get rid of all the compiler 6:38 errors we're seeing here since we're coding in the reverse order. 6:42