One, create a project
Before creating the project, we first get tomcat to our eclipse. Of course, if you use idea, you don’t need to do this operation, just skip it.
We click on the window to find the show view, then we select other, find Servers, and then select, click open
After that, we can see that there is a server in the shortcut box below
After that, we click on the No servers are available... this, add the tomcat that we downloaded last time
Finish directly
At that time, we can start our tomcat through here, and the province has to go to the directory to start
With this, we go to create a Web project, here, we need to create a Java project that can be deployed in tomcat
Here we choose Dynamic Web Project (Dynamic Web Project), and then next
Here we give this project a name, and then we choose the server at runtime, and another is a web module version, this we choose 2.5! ! ! (Because a web.xml file is missing after 2.5, to avoid manual creation, we use this)
Then finish directly
This is a directory structure just created for our entire web project
src puts our Java source code
There is only one file in meta-inf, this is the sticky note information, you can Baidu for details
There is a lib folder in web-inf, in which we will put some jar packages in the future. For example, we need to connect to the database in the future. We need to put the jar packages in the lib, and then add them to the build path, then we can use Some classes or class methods in the jar package
Mainly let's look at web.xml now, this is a key point
As you can see, there are very few tags in this initialized web.xml, just a few. We will configure many things here in the future. We will use them frequently. I hope everyone can pay attention to it.
Second, the realization of HelloWorld
Next, let's implement HelloWorld, we create an html under the WebContent folder, the name is index.html
Then we write some content in our body
Then we add this item to our tomcat, right-click the tomcat we just added, and select Add and Remove
Then select our project in Available, click Add, we can see our project in Confired, and then click Finish
However, this is not enough, we still need to start our tomcat
Similarly, we right-click tomcat and select Start
In the case of no error, we see this Server startup in xxx ms, it means the startup is complete, and then we proceed to visit our project
http://localhost:8080/HelloWorld (Ip + port + project name)
As you can see, in this way we have successfully built a most basic dynamic website.
Three, Jsp
We just created a html, we will now create a Jsp
If we create it, we still create it in the same directory as the html
Then we look at our Jsp file
We can find that there is an additional <%@ page... thing on the top. Let’s ignore it. Let’s talk about it later and look down. In fact, it’s not difficult to find that the following are our html codes. Next , We also write some content here
Then the question comes, let’s save
You can see such an error. Here, we need to modify the encoding format of the page. The default is ISO-8859-1 . We change them to UTF-8.
There are three places in total, let’s save it again
Is ok
Then we restart the server
Here we can choose Stop, and then go to Start, or directly choose Restart
After restarting, let’s visit the path just now
As you can see, it is still OK, and then we will visit the jsp page (here we need to specify the path to the specific page)
We click
Ok, no problem
Four, packaging
We packaged our HelloWorld project just now
Packaging is to facilitate delivery and deployment. We can't put an eclipse on the server, and then start and access, we directly generate a file, then as long as there is an environment, we can continue to run directly.
For packaging, we can use a simple export. Before that, we stop the tomcat server
Right-click our project and select export
Find war
We need to package a file in this format, select next
Then we choose this Browse, this is where the packaged files are placed, I choose to go to the desktop here
Click Finish, then switch to our desktop, you can see a file with a .war suffix
Then we put it in our local tomcat webapps
Let's start our server
After the startup is complete, let's take a look at our webapps directory
We can see that there is an additional HelloWorld directory, let's click in and take a look
As you can see, it is actually very similar to the project in our development tool. Let’s open WEB-INF and take a look.
There is one more classes folder in this one. We will put our Java code in this one. But because we haven’t written it yet, this one is empty now. The others are the same as our project. Everyone is left with their own take a look
Next, let's open the work directory again
And then keep going in
As you can see, there is also a HelloWorld directory, but now it is an empty directory, let’s request our project now
It’s no problem to request the html page first. At this time, the directory in the work is still empty.
Let's request another Jsp page
It's also OK, and there are things in our work folder
Click inside
As you can see, there are two files, this is what we said in the previous lesson, Jsp is actually Java, and then we look at the .Java file
Below we can see this thing, is it very familiar, this is our page, and finally it will be converted into Java code, and then output
Let's stop here for this section, everyone digest it, we will continue to talk about it later.
If you don’t understand, you can chat privately on my QQ: 2100363119, and you are also welcome to visit my website: https://www.lemon1234.com\ Thank you all