Detailed explanation of the process of deploying Tomcat and creating the first web project in IDEA 2020.3.1

Tomcat Introduction

Tomcat is a core project of the Jakarta project of the Apache Software Foundation, developed jointly by Apache, Sun and some other companies and individuals. Thanks to Sun's participation and support, the latest Servlet and JSP specifications can always be reflected in Tomcat. Tomcat 5 supports the latest Servlet 2.4 and JSP 2.0 specifications. Because Tomcat has advanced technology, stable performance, and is free, it is deeply loved by Java enthusiasts and recognized by some software developers, becoming a relatively popular Web application server.

Tomcat deployment

Download Tomcat
Open the tomcat homepage and select the version you want to download. I downloaded tomcat8.5 here.

According to the system type of your computer, select the 64-bit or 32-bit compressed package and decompress it.

After decompression

Open IDEA, click Run at the top, and select Edit Donfiguration... , click Templates , find Tomcat server, and click local

4. Click Configure... and select the unzipped file. Remember the name is apache-tomcat-8.5.61

Creating a web project

First create an empty java project and take a screenshot here

Right click the project and click Add Framework Support , select the web application framework, and click OK

This will add a web directory to the project

Configure tomcat

If your error is not automatically handled here, it means that you did not do the previous step of configuring the web application.

( Habit ) Create two folders under WEB-INF: classes and lib
classes directory: Place bytecode files
lib directory: prevent jar packages that the project depends on

Configuring the project architecture

Click OK

( habit ) Change Application context / (here is to set the virtual directory. If it is /, you don’t need a virtual directory when accessing the website. You can directly enter localhost:8080 to access index.jsp)

Successful connection

The index.jsp file will be opened automatically.

Because index.jsp is the default homepage, there is no need to write a virtual directory. If you access other .html files, you need to write the file name after localhost:8080 (such as: localhost:8080/hello.html)

You can create a .java file under src and implement the servlet interface and its 5 methods, and write an output code under the service method, which will be used later.

Configuring the servlet

Method 1: Paste the following code in web.xml

 <!--Configure servlet-->
 <servlet>
 <servlet-name>demo1</servlet-name>
 <servlet-class>cn.utkvrjan.web.servlet.ServletDemo1</servlet-class>
 </servlet>

 <servlet-mapping>
 <servlet-name>demo1</servlet-name>
 <url-pattern>/demo</url-pattern>
 </servlet-mapping>

Paste it in the position shown in the picture

Method 2: Starting from Servlet 3.0, annotation configuration is supported. It is super simple. Just write @WebServlet(urlPatterns = "/demo1") or @WebServlet("/demo1") on the implementation class name to configure it.

Then start tomcat and enter localhost:8080/demo1 in the browser to access (Note: demo1 here is entered when configuring the servlet). The content you wrote under the service method of the servlet implementation class will be output in the IDEA console, which means that the servlet is configured correctly.

(Habit) Hot deployment : Change Tomcat to: When updating resources in the file, let Tomcat restart (re-deploy the project), so that you don't need to manually restart the server after changing the file, which is more convenient.

If you select Update resources and classes here, you will also need to redeploy when you change the Java code. Since there are many changes to the Java code, this may affect performance, so don't select it.

This is the end of this article about deploying Tomcat in IDEA 2020.3.1 and creating the first web project. For more information about deploying Tomcat in IDEA 2020.3 and creating the first web project, please search for previous articles on 123WORDPRESS.COM or continue to browse the following related articles. I hope you will support 123WORDPRESS.COM in the future!