Hey there, welcome back friends. In this video, we will try to understand how to perform an update operation on our resource. So let's get started. Now first of all, we must update our controller, let us add an method, this would be a public method, the return type would be wide, and name would be update post. Now, definitely in order to update our post of a resource, definitely First of all, we would require the entire resource, the updated values, and also the ID of the specific resource where we need to perform the update operation right. So first object would be like post and name of the object would be post.

And the second thing is nothing but an entity which would be ID. All right, so this is good And now we will call it our service layer. So, it would be like new post service dot update post and we will pass on post and it now this method update post is not available with us as of now, we will add this method in couple of minutes. First of all let us add in the request mapping for the method and this would be similar to the request mapping of the Add POST method. So, we will copy this part and we will paste this in here. All right, and the value would be slash posts slash ID.

Now, again this ID would be what this ID would be a variable a get value right So, let us make use of pair of braces in here. This is cool. And now we need to use this value this ID value to initialize this variable ID. So, that has to attack and the ways very simple. We have already seen. This this would be like a PATH variable All right.

So, now, we will initialize this variable using the value on the URL, then moving forward, we need to also initialize this object post and in order to do that, we have a yet another annotation request body All right. So, this is good. Now, let me hover upon this particular method and let us create this method in our service layer. All right. Now, in order to update this particular method, we need to use a for loop. So let us do that in here we will type in four int i equals to zero is less than posts dot size, and then definitely i plus plus.

So this is nothing but a standard for loop and inside this for loop, first of all, we must get an object of the current iteration the way is very simple. In here double tap and post temp post equals posts post as nothing but our list here is our post list. And if we check one of the methods is get now using this get we can retrieve element based on our index and the indexes I write. So, we are iterating over this error list and based on this error list, we are retrieving the information one by one. All right and using this temporary variable we will try to compare the variable with the existing ID. So, how it will work it would be like if temp post dot get post ID equals to equals to ID in this case, we will update the information now updating the information is again very simple.

It would be like posts dot Set and using the index value I, we will update the information. And we will pass on the information which we receive as a parameter to this method, which is post. All right. So this is good enough, no rocket science. And once everything is done, we will simply return. Here we go.

So, this is good, and we will also return the controller back to our controller. The controller looks good, but there is a issue it is good that I have identified this right away. The method needs to be put not post so there was a silly mistake though. All right, so now things are good enough let me relaunch this application. Here we go. The application is up and running.

Let me navigate to Google Chrome and let us navigate to our URL slash post and here is the list of information which is there on our list. Now, let us try to update the information with it. Five. So let me first of all, show you the information right away. Here is the information. Let me copy this information again.

And now to this specific URL, we will perform a put request. All right. And in here, let me add in raw information, this would be but post ID five. And the title would be, for example, JSF. Overview. And let me also make use of a pair of parenthesis and update a notifier as updated.

Let me copy this notifier for body as well. All right, so now here is the updated information, which is cool enough. And we need to also specify the header value, which is content type. So our type is JSON, which would be like application slash JSON. All right, so this looks good to me. Let me send the request and there is no response returned.

This means that our response is a blank. This means that there is no issue. everything is working properly. Let me check the information with ID five and here is the updated information. All right, so this is good, this is nice that how easily we are able to update the information using a simple method. Alright, so in our next video, we will also try to understand how we can perform the Delete operation on our list.

All right, so that's it for today. I hope you guys enjoyed this video. Thanks for watching. Have a nice day and take care