Develop Reference

How to use the browser to access tomcat on port 8080?

I have a remote server, and its default port is 8080, but you know the browser default use 80 port to access it, so can not access my tomcat.
How to configure it to access the tomcat's 8080 port?
It is under the windows.
If I use www.example.com:8080 in the browser I can access the server, but if I use www.example.com I can not access it.
EDIT
I use Tomcat + IIS (Server Consolidation), IIS occupy the 80 port.

You cannot access the URL on http://www.example.com because the browser will try to make a TCP connection on port 80 while tomcat is listening to post 8080.
If you want to change the port tomcat is listening to, see this question
Another option is to use a proxy in front of your tomcat server. You can use apache web server or Nginx. They can listen to port 80 and forward your request to the tomcat server on port 8080.
Update
As mentioned in the comments below, as the post80 is already taken, adding reverse proxy cannot help. Because the reverse proxy will not be able to listen to port 80.
It is recommended to see which process is using port 80 and then a proper solution can be implemented.
Update
As IIS is listening on port 80, it is recommended to configure IIS to act as the reverse proxy.
You can follow this link to do so.

You can change tomcat connector port number.
Navigate to /tomcat-root/conf folder. Within you will find the server.xml file.
Open the server.xml and search for connector port and change it.
<Connector port="8080" protocol="HTTP/1.1"
connectionTimeout="20000"
redirectPort="8443" />

How do i rewrite url using urlrewrite in RestExpress

I have a small REST-api using port
{ip}:8081/{crud-operations-name}
and I have a website that points to this address but the problem is i still have to put port :
8081
all the time.
Actually I could just set my Java server to run on port :
80
, but that would lead to update all my clients(mobiles app) to listen on port 80 not on 8081 (Am i correct that all http request defaults to port 80?Correct me if im wrong). So I guess a better way is to rewrite the url when it comes to the Rest-Server of mine.
What I would want is like the behavior of htaccess hiding the port, Is it possible in urlrewrite using RestExpress?

You can add a port redirect to your Tomcat's server.xml file. You can invite your users to access the site without specifying a port number, meaning that everyone will hit the default port 8080. When anyone accesses using port 8080, the request will be redirected to 8081 which port presumably has some security settings associated with it.
<Connector port="8080" protocol="HTTP/1.1"
connectionTimeout="20000"
URIEncoding="UTF-8"
enableLookups="false"
redirectPort="8081" />

tomcat server's port number not changing

I have J2EE application and I want to change the port number of my tomcat server.
I have changed the Connector tag to
<Connector port="8091" protocol="HTTP/1.1"
connectionTimeout="20000"
redirectPort="8443" />
But its still giving error Port is already used.
Do we need to change somewhere else too ?

There are three ports in default tomcat installations: 8005, 8009 and 8080. You'll need to change all of them.
Just search for port= in server.xml and change all the values.

may be your 8091 port is occupied try from command port how many ports are in use using netstat -ano which will give you already used port

I had the same issue until I figured that I had a "CATALINA_HOME" environment variable pointing to another tomcat folder. So changing the port in the server.xml file had no effect since it wasn't the one readed at startup.
I simply removed (using REM) this line in startup.bat :
REM if not "%CATALINA_HOME%" == "" goto gotHome

See if you are not using doors in another program.
The default ports in server.xml is as follows:
Tomcat admin port : 8005
HTTP/1.1 : 8080
AJP/1.3 : 8009
I believe that will resolve this problem.

Gets the error without port number even when it is default port in tomcat?

I have tomcat installed on my local machine. I see it in server.xml where I have below entry
<Connector executor="tomcatThreadPool"
port="${http.port}"
protocol="HTTP/1.1"
connectionTimeout="20000"
redirectPort="${https.port}"
acceptCount="100"
maxKeepAliveRequests="15"/>
where http.port value in catalina.properties is 8080 .
But every time I try to access my application it url http://localhost/myApp I get error
could not connect to localhost but it works fine http://localhost:8080/myApp. I am not getting why it expects
the port 8080 when it is already a default port? What should I do so that I do not have to mention port?

When you write http://localhost/myApp on the Address Bar of your Browser, the request always goes to Port 80, and not Port 8080. So the default is Port 80 here. For http://localhost/myApp to work you need to install something like Apache HTTP Server.
Then you can configure it with the help of a connector like mod_jk or mod_proxy to use http://localhost/myAppi, instead of http://localhost:8080/myApp. So that what ever request comes on Port 80 can be diverted to Port 8080 automatically.
Once you will download mod_jk, simply extract the file mod_jk.so to the modules folder of your Apache HTTP Server.
Hopefully the steps written here How to Configure Apache HTTP Server with Apache Tomcat, might help you in doing that.

On a Windows platform all you have to do is changing the port number in server.xml from 8080 to 80 and you are done.
The above is not true for Unix/Linux environments. Changing the port number might work on Windows but i think it might be slightly tricky on Unix/Solaris.
Under UNIX all ports <1024 are "privileged" ports. Only root may open a privileged port. It is still possible but keep in mind that it is not as simple as changing the port number when on Unix.
There are a number of workarounds for this.
http://raibledesigns.com/rd/entry/how_to_run_tomcat_on
http://mihail.stoynov.com/2011/04/04/howto-start-tomcat-on-port-80-without-root-privileges/
http://java-notes.com/
http://www.klawitter.de/tomcat80.html

SSL Tomcat Configuration

I am using tomcat 5.5 and configured keystore and added this connector inside server.xml file
<Connector port="443" minProcessors="5" maxProcessors="75"
enableLookups="true" disableUploadTimeout="true"
acceptCount="100" debug="0" scheme="https" secure="true";
clientAuth="false" sslProtocol="TLS"/>
But I am not sure why when I type in https://locahost the browser tells me "This program cannot display the webpage".

Did you check Tomcat's logs?
Perhaps the connector could not start up.
Perhaps Tomcat could not read or find the .keystore you configured.
Perhaps the .keystore has a password which Tomcat does not know about.
Perhaps another process is already bound to that port.
The logs will probably tell you exactly which of these is going on.

Possibly you have your browser configured to use a web proxy. In this case, make sure that localhost and 127.0.0.1 are exceptions to using this proxy under the browser's preferences or options. ALSO make sure that localhost is mapped to 127.0.0.1 in your /etc/hosts file. Which in windows is under \WINDOWS\system32\drivers\etc\hosts.

Try to add the port
localhost :443