1. Apache Tomcat 7 Download

This practical can be completed in a 3-hour session. This installation and configuration guide is applicable to Tomcat 9, and possibly the earlier versions. Take note that Tomcat 9 requires JDK 1.8 and later. You can check your JDK version via command ' javac -version'. Introduction Web Application (Webapp) A web application (or webapp), unlike standalone application, runs over the Internet. Examples of webapps are google, amazon, ebay, facebook and twitter.

A webapp is typically a 3-tier (or multi-tier) client-server database application run over the Internet as illustrated in the diagram below. It comprises five components:. HTTP Server: E.g., Apache HTTP Server, Apache Tomcat Server, Microsoft Internet Information Server (IIS), nginx, Google Web Server (GWS), and others. HTTP Client (or Web Browser): E.g., Internet Explorer (MSIE), FireFox, Chrome, Safari, and others. Database: E.g., Open-source MySQL, Apache Derby, mSQL, SQLite, PostgreSQL, OpenOffice's Base; Commercial Oracle, IBM DB2, SAP SyBase, MS SQL Server, MS Access; and others.

Client-Side Programs: could be written in HTML Form, JavaScript, VBScript, Flash, and others. Server-Side Programs: could be written in Java Servlet/JSP, ASP, PHP, Perl, Python, CGI, and others. The typical use-case is:. A user, via a web browser (HTTP client), issues a URL request to an HTTP server to start a webapp. The HTTP server returns an HTML form (client-side program), which is loaded into the client's browser. The user fills up the query criteria inside the form and submits the form. The client-side program sends the query parameters to a server-side program.

The server-side program receives the query parameters, queries the database based on these parameters, and returns the query result to the client-side program. The client-side program displays the query result on the browser. The process repeats for the next request. Hypertext Transfer Protocol (HTTP). HTTP is an application layer protocol runs over TCP/IP. The IP provides support for routing and addressing (via an unique IP address for machines on the Internet); while TCP supports multiplexing via 64K ports from port number 0 to 65535.

The default port number assigned to HTTP is TCP port 80. HTTP is an asynchronous request-response application-layer protocol.

A client sends a request message to the server. The server then returns a response message to the client. In other words, HTTP is a pull protocol, a client pulls a page from the server (instead of server pushes pages to the clients). The syntax of the message is defined in the.

Apache Tomcat HTTP Server Apache Tomcat is a Java-capable HTTP server, which could execute special Java programs known as 'Java Servlet' and 'Java Server Pages (JSP)'. Tomcat is an open-source project, under the 'Apache Software Foundation' (which also provides the most use, open-source, industrial-strength Apache HTTP Server). The mother site for Tomcat is. Alternatively, you can find tomcat via the Apache mother site @. Tomcat was originally written by James Duncan Davison (then working in Sun), in 1998, based on an earlier Sun's server called Java Web Server (JWS).

It began at version 3.0 after JSWDK 2.1 it replaced. Sun subsequently made Tomcat open-source and gave it to Apache. The various Tomcat releases are:. Tomcat 3.x (1999): Reference Implementation (RI) for Servlet 2.2 and JSP 1.1. Tomcat 4.x (2001): RI for Servlet 2.3 and JSP 1.2. Tomcat 5.x (2002): RI for Servlet 2.4 and JSP 2.0. Tomcat 6.x (2006): RI for Servlet 2.5 and JSP 2.1.

Tomcat 7.x (2010): RI for Servlet 3.0, JSP 2.2 and EL 2.2. Tomcat 8.x (2013): RI for Servlet 3.1, JSP 2.3, EL 3.0 and WebSocket 1.0.

Tomcat 9.x (2018): RI for Servlet 4.0, JSP 2.3, EL 3.0, WebSocket 1.0, JASPIC 1.1. Tomcat is an HTTP application runs over TCP/IP. In other words, the Tomcat server runs on a specific TCP port from a specific IP address. The default TCP port number for HTTP protocol is 80, which is used for the production HTTP server. For test HTTP server, you can choose any unused port number between 1024 and 65535. How to Install Tomcat 9 and Get Started with Java Servlet Programming STEP 0: Create a Directory to Keep all your Works I shall assume that you have created a directory called ' c: myWebProject' (for Windows) or ' myWebProject' (for Mac OS X) in your earlier exercises. Do it otherwise.

This step is important; otherwise, you will be out-of-sync with this article and will not be able to find your files later. STEP 1: Download and Install Tomcat. For Ubuntu Read '. You need to switch between these two articles.

For academic learning, I recommend ' zip' (or ' tar.gz') version, as you could simply delete the entire directory when Tomcat is no longer needed (without running any un-installer). You are free to move or rename the Tomcat's installed directory.

You can install (unzip) multiple copies of Tomcat in the same machine. For production, it is easier to use the installer to properly configure the Tomcat. Tomcat's Directories Take a quick look at the Tomcat installed directory. It contains the these sub-directories:. bin: contains the binaries; and startup script ( startup.bat for Windows and startup.sh for Unixes and Mac OS), shutdown script ( shutdown.bat for Windows and shutdown.sh for Unix and Mac OS), and other binaries and scripts.

conf: contains the system-wide configuration files, such as server.xml, web.xml, and context.xml. webapps: contains the webapps to be deployed. You can also place the WAR (Webapp Archive) file for deployment here. lib: contains the Tomcat's system-wide JAR files, accessible by all webapps. You could also place external JAR file (such as MySQL JDBC Driver) here.

logs: contains Tomcat's log files. You may need to check for error messages here. work: Tomcat's working directory used by JSP, for JSP-to-Servlet conversion. STEP 2: Create an Environment Variable JAVAHOME. (For Mac OS) Skip this step.

No need to do anything. STEP 3: Configure Tomcat Server The Tomcat configuration files are located in the ' conf' sub-directory of your Tomcat installed directory, e.g. ' c: myWebProject tomcat conf' (for Windows) or ' /myWebProject/tomcat/conf' (for Mac OS X). There are 4 configuration XML files:.

server.xml. web.xml. context.xml Make a BACKUP of the configuration files before you proceed!!! Step 3(a) ' conf server.xml' - Set the TCP Port Number Use a programming text editor (e.g., NotePad, TextPad, Sublime, Atom for Windows; or gEdit, jEdit, Sublime, Atom for Mac OS) to open the configuration file ' server.xml', under the ' conf' sub-directory of Tomcat installed directory. The default TCP port number configured in Tomcat is 8080, you may choose any number between 1024 and 65535, which is not used by an existing application.

We shall choose 9999 in this article. (For production server, you should use port 80, which is pre-assigned to HTTP server as the default port number.) Locate the following lines (around Line 69) that define the HTTP connector, and change port='8080' to port='9999'.

Apache Tomcat 7 Download

Locate the following lines (around Line 108) that define the 'default' servlet; and change the 'listings' from ' false' to ' true'. Default org.apache.catalina.servlets.DefaultServlet debug 0 listings true 1 Step 3(c) ' conf context.xml' - Enabling Automatic Reload We shall add the attribute reloadable='true' to the element to enable automatic reload after code changes. Again, this is handy for test system but not for production, due to the overhead of detecting changes. Locate the start element (around Line 19), and change it to. STEP 4: Start Tomcat Server The Tomcat's executable programs and scripts are kept in the ' bin' sub-directory of the Tomcat installed directory.

Step 4(a) Start Server. For Mac OS I assume that Tomcat is installed in ' /myWebProject/tomcat'. To start the Tomcat server, open a new 'Terminal' and issue: cd /myWebProject/tomcat/bin // Change directory to your Tomcat's binary directory./catalina.sh run // Start tomcat server A new Tomcat console window appears. Study the messages on the console. Look out for the Tomcat's port number (double check that Tomcat is running on port 9999).

Future error messages will be send to this console. System.out.println issued by your Java servlets will also be sent to this console. Xxxxx INFO main org.apache.coyote.AbstractProtocol.start Starting ProtocolHandler ' http-nio-9999' xxxxx INFO main org.apache.coyote.AbstractProtocol.start Starting ProtocolHandler 'ajp-nio-8009' xxxxx INFO main org.apache.catalina.startup.Catalina.start Server startup in 1325 ms (Skip Unless.) Cannot Start Tomcat: Read '. Step 4(b) Start a Client to Access the Server Start a browser (Firefox, Chrome) as an HTTP client.

Issue URL ' to access the Tomcat server's welcome page. The hostname ' localhost' (with IP address of 127.0.0.1) is meant for local loop-back testing inside the same machine. For users on the other machines over the net, they have to use the server's IP address or DNS domain name or hostname in the format of ' serverHostnameOrIPAddress:9999'. Try issuing URL to view the servlet and JSP examples.

Try running some of the servlet examples. Step 4(c) Shutdown Server.