Apache Tomcat is basically a Web Server and Servlet system which is an open-source (i.e. freely available on the internet) and is created by Apache Software Foundation. It is the server mostly used by Java Developers.
The server is nothing but a computer program that provides service to other computers.
There are basically two types of server:
Application Server Web ServerApache Tomcat offers HTTP protocol, which means the user can connect with the server from anywhere by the URL provided and can access the Java application.
This is very easy and simple to install and is compatible with any Operating System.
Answer: It is required to run Java Web Applications on the host and server-based systems. It also helps to run JSP and Servlets.
The name of the inbuilt Web Container in Tomcat is Catalina which is present in the bin directory.
Catalina is used for loading all the requests related to HTTP and can instantiate the objects of GET () and POST () methods.
There are basically two types of batch files with which we can Start and Stop the Server.
They are as follows:
Startup.bat Shutdown.batAnswer: The vital configuration file that is used in Apache Tomcat is httpd.conf
The configurations files of Catalina include:
XML Properties Policy Tomcat-users.xmlThe benefits of Running Tomcat as service are:
Automatic Startup – If tomcat window service starts up automatically then it would be helpful when we want to start the system remotely. Security – It allows you to execute under a special account which is protected from the other accounts. Starting off the server without active user login: So even if there is no active user, the available server can be started.There is a Web apps directory in Tomcat under which all the web components JSP, Servlets, HTML are placed. Hereby putting all the files into a single folder we can compress the files into a single unit which has .WAR extension.
Now, we can easily deploy the web application by putting the WAR file in the Web apps directory. And, when the server starts it extracts all the web components.
There are basically four configured Tomcat Valves which are mentioned below:
Access Log Remote Host Filter Remote Address filter Request DumperTomcat Coyote is basically an HTTP connector based on HTTP/ 1.1 configuration which accepts and sends the web request to the Tomcat engine and again reverts to the client which makes the request.
Answer: There are multiple ways to do it and some of them are mentioned below:
Implementing SSL Make use of Cloud-based security provider. Integrating with Web Application Firewall.Apache Tomcat is used to host the web contents whereas Apache Web server is an HTTP server that is built to serve the static contents.
There is always a possibility to integrate Apache Tomcat and Apache Web Server.
There are many web servers as mentioned below:
LiteSpeed Web Server GWS Web Server Microsoft IIS Web Server Nginx Web Server Jigsaw Web Server Sun Java System Web Server Lighttpd Web ServerFor this, we can say that we have worked on httpd – 2.2.3
Adding the logLevel Debug provides you with more information in the error log in order to debug an issue.
Yes, it is possible to serve the Content out of a directory other than the Document Root directory with the help of “Alias” command.
Yes, there is a chance to cache files which are viewed frequently by using
Yes, we can restrict the user to upload files on our web server by using the “LimitRequestBody” directive.
Example: LimitRequestBody 20000
Now I have put a limit of 20000 files, so when this mark is reached then the user will not be able to upload any more files in the server.
The Apache Service is controlled using a script called the apachectl.
So, to stop the service, we need to run the below-mentioned commands.
#apachectl stop [for Ubuntu based system] # /etc/inid.t/httpd.stop [for red hat based system]Apache runs with a user “nobody” and httpd daemon.
The location of the main configuration file is:
# /etc/httpd/conf/httpd.conf # /etcapache2.confThe default session timeout 30 minutes in tomcat and can change in $TOMCAT_HOME/conf/web.xml via modify below entry
The default session timeout 30 minutes in tomcat and can change in $TOMCAT_HOME/conf/web.xml via modify below entry
If you want tomcat to accept requests for different hosts e.g. www.myhostname.com then you must
Create $/www/appBase , $/www/deploy, and $/conf/Catalina/www.myhostname.com Add a host entry in the server.xml file Create the the following file under conf/Catalina/www.myhostname.com/ROOT.xml Add any parameters specific to this hosts webapp to this context file Put your war file in $/www/deploy When tomcat starts, it finds the host entry, then looks for any context files and will start any apps with a context.Your set up might have been not done well.
Make sure you have added tomcat root directory path in the CATALINA_HOME environment variable and added the bin path in the path variable.
We can easily override home page via adding welcome-file-list in application $TOMCAT_HOME/webapps//WEB-INF /web.xml file or by editing in container $TOMCAT_HOME/conf/web.xml
In $TOMCAT_HOME/conf/web.xml, it may look like this:
index.html index.htm index.jsp Request URI refers to a directory, the default servlet looks for a “welcome file” within that directory in following order: index.html, index.htm and index.jsp
8080 is the default HTTP port that Tomcat attempts to bind to at startup. To change this, we need to change port in $ TOMCAT_HOME /conf/server.xml, in that we can search 8080 and after getting below statement
We can change 8080 to other port like 8081, we need to restart tomcat to take effect. We required changes in URL as http://localhost:8081/.
The default session timeout 30 minutes in tomcat and can change in $TOMCAT_HOME/conf/web.xml via modify below entry
If you want tomcat to accept requests for different hosts e.g. www.myhostname.com then you must
Create $/www/appBase , $/www/deploy, and $/conf/Catalina/www.myhostname.com Add a host entry in the server.xml file Create the the following file under conf/Catalina/www.myhostname.com/ROOT.xml Add any parameters specific to this hosts webapp to this context file Put your war file in $/www/deploy When tomcat starts, it finds the host entry, then looks for any context files and will start any apps with a context.The purpose of NAT protocol is to hide private IP address from public IP address and give a certain level of security to the organization.
Tomcat Servlet Container is a servlet container. The servlets runs in servlet container. The implementation of Java Servlet and the Java Server Pages is performed by this container. Provides HTTP web server environment in order to run Java code. Reduces garbage collection Native Windows and Unix wrappers for platform integrationNo. If you can edit Tomcat’s startup scripts, you can add “-D” options to Java. But there is no way to add such properties in web.xml or the webapp’s context.
Struts or any webserver makes new thread for each new request. so multiple request is served with new request object.
If you are running a bean property, use the .operator, and if you are executing a map value or an array index, it is preferred to use the [] operator. Although you can use these operators interchangeably.
Transaction with HTTP request and HTTP response is called webserver.
Using the internet listening the HTTP request and providing the HTTP response is also called webserver.It gives only html output.It will not process business logic .They can provide Http server.They are static.
Tom coyote is an HTTP connector based on HTTP/ 1.1 specification which receives and transport web requests to the Tomcat engine by listening to a TCP/IP port and sent request back to the requesting client.
In Tomcat, two types of connectors are used:
HTTP Connectors: It has many attributes that can be changed to determine exactly how it works and access functions such as redirects and proxy forwarding AJP Connectors: It works in the same manner as HTTP connectors, but they practice the AJP protocol in place of HTTP. AJP connectors are commonly implemented in Tomcat through the plug-in technology mod_jk.The basic difference between a web server and an application server is Webserver can execute only web applications i,e servlets and JSPs and has only a single container known as Web container which is used to interpret/execute web applications. Application server can execute Enterprise application, i,e (servlets, jsps, and EJBs)
it is having two containers:
Web Container(for interpreting/executing servlets and jsps) EJB container(for executing EJBs).it can perform operations like load balancing , transaction demarcation etc.
You would use Tomcat to handle connection, when you are running Tomcat as a stand-alone web server.
Four types of valves Tomcat is configured with:
Access Log Remote Address Filter Remote Host Filter Request DumperA tomcat valve- a new technology is introduced with Tomcat 4 which enables you to link an instance of a Java class with a specific Catalina container.
No. If you can edit Tomcat’s startup scripts, you can add “-D” options to Java. But there is no way to add such properties in web.xml or the webapp’s context.
By using plug module
It displays the default tables in the database.
You have to follow the standard instructions for when the isapi_redirector.dll
Configure IIS to use “integrated windows security”
Ensure that in the server.xml you have disable tomcat authentication
If you are running a bean property, use the .operator, and if you are executing a map value or an array index, it is preferred to use the [] operator. Although you can use these operators interchangeably.
The default port for Tomcat is 8080. After initialising Tomcat on your local machine, you can verify if Tomcat is running the URL: http://localhost:8080
In Tomcat, two types of connectors are used
HTTP Connectors: It has many attributes that can be changed to determine exactly how it works and access functions such as redirects and proxy forwarding AJP Connectors: It works in the same manner as HTTP connectors, but they practice the AJP protocol in place of HTTP. AJP connectors are commonly implemented in Tomcat through the plug-in technology mod_jk.Running Tomcat as a windows service provides benefits like
Automatic startup: It is crucial for environment where you may want to remotely re-start a system after maintenance Server startup without active user login: Tomcat is run oftenly on blade servers that may not even have an active monitor attached to them. Windows services can be started without an active user Security: Tomcat under window service enables you to run it under a special system account, which is protected from the rest of the user accountsJSPs, servlets, and their supporting files are placed in the proper subdirectories under the web apps directory in Tomcat. You can make all the files under the web apps directory into one compressed file, which ends with .war file extension. You can execute a web application by placing a WAR file in the webapps directory. When a web server starts executing, it pulls out the WAR file’s contents into the appropriate webapps sub-directories.
A tomcat valve- a new technology is introduced with Tomcat 4 which enables you to link an instance of a Java class with a specific Catalina container.
