Using ES6, you can write code that runs in multiple browsers and on your server. But there is sometimes a warning message that you might have come across – “React Hook Warnings for async function in useEffect: useEffect function must return a cleanup function or nothing”. This article contains tips on what the warning means and how to fix it.

When dose this error appear?

Before find the cause of the error, let’s explore the Web API- Application Programing Interface firstly.  In the programming of computer “application programming interface” (API) can be described as a collection of subroutine specifications, protocols and tools to build applications and software.

In simple phrases, API is some kind of interface with several functions that permit developers to connect with specific characteristics or data from an operating system, application as well as other functions.

Let’s see the problem when attempting to use the webAPI from a Gradle project, you may get the following issue.

Web server failed to start. Port 8080 was already in use.

How To Deal With The Error “Web server failed to start. Port 8080 was already in use”?

Option 1: Modify Port

By including the line below to application.properties, you can modify the application’s default port.

server.port = 3000 # for example

Your error will be resolved after modifying port.

Option 2: That port must be shut down.

Your error will be resolved by terminating the port process. If you’re using Windows, simply type this command. To begin, open CMD and run it as an administrator. Tune this command in the terminal after that.

netstat -a -o -n

This is what the result will look like.

After the : sign, you may see Port in the Local Address column. For instance, the first local address is 0.0.0.0:80, which means the port is 80.

Next, choose the process id (not the port) that the port is currently running, then use this command and press enter.

taskkill /F /PID <process_id_here>

Option 3: Set the property in application.properties (or .yml)

Set the following property in application.properties (or .yml):

spring.main.web-application-type=none

Change the port using the server.port property (in the application’s .properties/.yaml file, as a command line argument at startup) if the application is a Web application,

Option 4: Using CurrPorts

For the kill the that port problem can help

Using CurrPorts software you can view what are the running all ports in your machine and you can kill that port if you want.

Now, download CurrPorts via this link here

Conclusion

Web API as the name implies is an API that is accessible over the internet that can be used to access the HTTP protocol. It’s a notion and is not a specific technology. It is possible to build a Web API using different technologies like Java, .NET etc. For instance twitter’s REST APIs allow the ability to programmatically write and read data, using the twitter API, which we can then integrate abilities into our applications.

We hope you enjoyed our article about Java. With this knowledge, we know that you can fix your “Web server failed to start. Port 8080 was already in use” error quickly by following these steps!

If you still have any other questions about fixing this syntax error, please leave a comment below. Thank you for reading!