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This article mainly introduces "how to use tomcat with nginx". In daily operation, I believe many people have doubts about how to use tomcat with nginx. The editor consulted all kinds of materials and sorted out simple and easy-to-use methods of operation. I hope it will be helpful to answer the doubts about "how to combine tomcat with nginx". Next, please follow the editor to study!

Summary of the use of tomcat combined with nginx

I believe many people have heard of nginx, this little thing is slowly eating up the share of apache and IIS. So what exactly does it do? Maybe many people may not understand.

When it comes to reverse proxy, many people may have heard of it, but many people may not know exactly what reverse proxy is. Take a description from Baidu encyclopedia:

Reverse proxy (Reverse Proxy) means that the proxy server accepts the connection request on the internet, then forwards the request to the server on the internal network, and returns the result obtained from the server to the client requesting the connection on the internet. At this time, the proxy server is externally represented as a server.

It's very straightforward here. Reverse proxy is actually a proxy server responsible for forwarding, which seems to act as a real server, but in fact it is not. The proxy server just acts as a forwarding server and gets the returned data from the real server. In this way, in fact, this is what nginx has done. We asked nginx to listen on a port, such as port 80, but in fact we forwarded it to tomcat on port 8080 to handle the real request. When the request is completed, tomcat returns, but the data is not returned directly at this time, but directly to nginx and returned by nginx. Here, we will think that nginx has processed it, but in fact it is tomcat.

When it comes to the above approach, many people may recall that static files can be handed over to nginx for processing. Yes, many places where nginx is used are used as static servers, which makes it easy to cache static files, such as CSS,JS,html,htm files.

No more gossip, let's just take a look at how nginx works.

1) of course, the software to be used should be downloaded. Go to the next one on the nginx website. The version I use now is 1.1.7, but basically all the later versions are compatible, and what we use is not too low-level, so there should be no change.

Here, since mine is windows, of course under the windows version. You have to start it first when you're done. Go to the nginx folder and start nginx directly to OK.

For example, I download and put it in D:\ software\ developerTools\ server\ nginx-1.1.7, and directly cmd after cd D:\ software\ developerTools\ server\ nginx-1.1.7. Some people who are not used to the command line may be surprised that it didn't get to that folder. Windows does not jump between partitions unless you specify it. So we need to directly d: as follows:

At this point we open the task manager and we can see that the two nginx.exe are fine there. This shows that we have already started, as to why there are two, we do not delve into it here.

At this point we open the task manager and we can see that the two nginx.exe processes are fine there. This shows that we have already started, as to why there are two, we do not delve into it here.

Now that we have started nginx, we can start tomcat, thinking that if we visit http://localhost directly, we can access tomcat directly.

Don't worry, let's take a look at what the nginx looks like after startup. If you visit http://localhost directly, you can see:

We can see that nginx started successfully, and now the access goes directly to the nginx directory.

So where are these actually configured? This involves nginx.conf, an important configuration file for nginx.

2) We can see that there is a conf folder in the nginx folder, in which there are several files. Regardless of the others, we open nginx.conf and see a paragraph.

This code is equivalent to a proxy server in server, and of course you can configure multiple.

Let's take a closer look at it:

Listen: indicates the port on which the current proxy server listens. The default is to listen on port 80. Note that if we configure multiple server, the listen needs to be configured differently, otherwise we can't be sure where to go.

Server_name: indicates where you need to go after listening, then we go directly to the local location, and then we go directly to the nginx folder.

Location: indicates the matching path. If / is configured, all requests are matched here.

Root: when root is configured, it means that when matching the path of the request, the corresponding file will be found in this folder, which is very useful for our later static file servo.

Index: when no home page is specified, the specified file is selected by default. It can have multiple files and load them sequentially. If the first one does not exist, find the second one, and so on.

The following error_page represents the error page, so let's not use it here for the time being, just ignore it.

So we know the specific configuration and how to make it go to tomcat when it accesses localhost. In fact, there are only two changes:

1 server_name localhost:8080; 2 3 location / {4 proxy_pass http://localhost:8080 5}

We have modified the above two places. My tomcat is on port 8080, which can be modified according to our own needs. Here is a new element, proxy_pass, which represents the proxy path, which is equivalent to forwarding, rather than the fact that root must specify a folder.

At this point, we modified the file, does it mean that we must first close the nginx and then restart, in fact, no, nginx can reload the file.

Let's run it directly:

Happy too early, we found a mistake:

What came? line 45 found an error and didn't want to find it on that line. So we looked carefully and found that the proxy_pass we joined was strange, no; sign ends, this is the problem, modify it directly, and then run it again, and find no error, OK.

If you don't want to load directly, but just want to see if there is anything wrong with your configuration file, you can type:

This checks for errors in the configuration file. All of our changes below assume that we run nginx-s reload to reload the configuration file after the modification is completed. Please note.

Everything is fine, and then we reopen http://localhost, and we see the following page:

At this time, we found that it is not just the welcome page, but the management page of tomcat, no matter what link we click, it is the same as directly visiting http://localhost:8080.

3) above, we directly tried a small example for nginx to forward, that is, the so-called reverse proxy. But in fact, our requirements will not be like this. We need to filter by file type. For example, jsp is directly processed by tomcat, because nginx is not a servlet container, so there is no way to handle JSP, while html,js,css, which does not need to be processed, is directly cached to nginx.

Let's configure the JSP page directly to tomcat, while some images such as html,png and JS will be cached directly to nginx.

At this time, the most important element is location, and it involves some regularities, but it is not difficult:

1 location ~\ .jsp$ {2 proxy_pass http://localhost:8080; 3} 4 5 location ~\. (html | js | css | png | gif) ${6 root DJV

We first need to remove the previous location / to prevent all requests from being intercepted.

Then let's take a look at http://localhost.

When we do not specify the jsp page, it will not be found, because there is no corresponding location match, so there will be a 404 error, and then jump to the nginx custom error page.

And when we visit it with http://localhost/index.jsp, we see a familiar page:

And those pictures all display normally, because the pictures are png, so look for them directly in the tomcat/webapps/ROOT directory. Of course, if we click on the Manager Application HOW-TO link, we find:

It still can't be found. Why? Because this is a html page, but it is not in the ROOT directory, but in the docs directory, but when we match html, we look in the ROOT directory, so we still can not find the page.

In general, if we need to use nginx for static file servo, we will generally put all static files, html,htm,js,css, etc., in the same folder, so that there will not be such a case as tomcat, because tomcat belongs to different projects, we can't do anything about it.

3) some people will say, these will only find one server, but what if we want to find another server automatically when one server dies? This is actually taken into account by nginx.

At this point, the proxy_pass we used before will be of great use.

Let's modify the first example before, that is, all agents:

The final modification is as follows:

1 upstream local_tomcat {2 server localhost:8080; 3} 4 5 server {6 location / {7 proxy_pass http://local_tomcat; 8} 9 #. Other omissions 10}

We added a upstream to the server and used it directly in the proxy_pass with the name http://+upstream.

Let's go to http://localhost directly, or the same effect as the first one. All the links are all right, which means we have the right configuration.

The server element in upstream must be noted that http://, cannot be added, but must be added in proxy_pass.

We just said that we can connect to another server if the server is down. How do we do that?

It's really simple to configure one more server in the local_tomcat in upstream. For example, I now have an extra jetty with a port of 9999, so we configure it as follows:

1 upstream local_tomcat {2 server localhost:8080; 3 server localhost:9999; 4}

At this point, we turn off tomcat and only turn on jetty. Let's run http://localhost to see what happens:

We see that it requests to the jetty page, but due to the mechanism of jetty, the jetty home page is not displayed at this time, let's ignore this. But our function of automatically using another server is implemented when one server is hung up.

But sometimes we don't want to visit another when it hangs, but we just want one server to have more access than the other. This can be specified by adding a weight= number at the end of the server. The higher the number, the greater the chance of the request.

1 upstream local_tomcat {2 server localhost:8080 weight=1; 3 server localhost:9999 weight=5; 4}

At this time, we give jetty a higher weight to give it a better chance to access. In fact, when we refresh http://localhost access, we find that jetty access is much more likely, and tomcat has almost no chance to access it. In general, if we have to use it this way, do not be too relevant, lest a server will be overloaded.

Of course, server also has some other elements, such as down means not to go to the server for the time being, and so on. These can be found in nginx's wiki. Maybe there's a lot of writing, and someone will have a problem, so how do you shut down nginx? This is a problem, in fact, just run nginx-s stop can be shut down.

At this point, the study on "how to use tomcat with nginx" is over. I hope to be able to solve your doubts. The collocation of theory and practice can better help you learn, go and try it! If you want to continue to learn more related knowledge, please continue to follow the website, the editor will continue to work hard to bring you more practical articles!

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