Creating a Web Application with Ant and Tomcat 4
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AddressBook's Addresses Database Table

Setting up the database depends on the database software being used. You will need to amend these instructions if you are not using MySQL. AddressBook employs a single table called Addresses in a database called Public. The Addresses table has seven fields:

• id, the primary key, a numeric field that is automatically incremented by the database software.
• surname, a 24-character field that holds the surname of the owner of the address.
• firstname, a 24-character field that holds the first name of the owner of the address.
• street, an 80-character field that holds the address' first line.
• district, an 80-character field that holds the address' second line.
• city, a 40-character field that holds the address' city.
• postcode, a 10-character field that holds the address' postcode.

Let's set up the MySQL database. Start the mysql command-line utility with root permissions. When requested, enter the password. Create the Public database and grant the mysqlusername permissions on that database, with a permission of mysqlpassword. The commands are:

# mysql -u root -p
mysql> create database Public;
mysql> grant all privileges on Public.* to mysqlusername@localhost \
identified by 'mysqlpassword' with grant option;
mysql> flush privileges;

Next, create the Addresses table in the Public database.

mysql> create table Addresses ( \
id        int(8) primary key auto_increment, \
surname   varchar(24) not null, \
firstname varchar(24) not null, \
street    varchar(80) not null, \
district  varchar(80) not null, \
city      varchar(40) not null, \
postcode  varchar(10) not null \
);

Commit the changes with the commit; command. To verify the table's configuration,issue the describe Addresses; command. You should get the following:

+-----------+-------------+------+-----+---------+----------------+
| Field     | Type        | Null | Key | Default | Extra          |
+-----------+-------------+------+-----+---------+----------------+
| id        | int(8)      |      | PRI | NULL    | auto_increment |
| surname   | varchar(24) |      |     |         |                |
| firstname | varchar(24) |      |     |         |                |
| street    | varchar(80) |      |     |         |                |
| district  | varchar(80) |      |     |         |                |
| city      | varchar(40) |      |     |         |                |
| postcode  | varchar(10) |      |     |         |                |
+-----------+-------------+------+-----+---------+----------------+

Now you can insert a row of data to test the database.

mysql> insert into Addresses (surname, firstname, street, district, \
city, postcode) values ("Smith", "John", "1, The High Street,", \
"Downtown,", "Metropolis.", "X99 9XX");
mysql> commit;
mysql> select * from Addresses;

This should produce the following output:

+----+---------+-----------+--------------+-----------+-------------+----------+
| id | surname | firstname | street       | district  | city        | postcode |
+----+---------+-----------+--------------+-----------+-------------+----------+
|  1 | Smith   | John      | 1, The       | Downtown, | Metropolis. | X99 9XX  |
|    |         |           | High Street, |           |             |          |
+----+---------+-----------+--------------+-----------+-------------+----------+

Notice that the address id has been automatically assigned a value of 1. AddressBook's database is now ready for use.

Configuring AddressBook's Development Directory

We are now ready to configure the development directory where AddressBook's source files are held, and the war directory where the Web application will be built and where the Web application's Web archive file will be held.

Download the AddressBook source files archive (AddressBook.zip). Unzip the archive. You now have the application's source files in a directory structure ready for processing by the Ant development tool, as you can see in Figure 3. There is no need to put AddressBook's development directory anywhere special -- I recommend that you put it somewhere in your home directory structure.

Lets have a look at these files:

AddressBook/build.properties

AddressBook/build.properties contains a number of configuration settings that are read into the AddressBook/build.xml file. To configure the build, you should edit the smaller build.properties file. Leave the more complex build.xml file alone as much as possible.

app.name=AddressBook
tomcat.home=/usr/local/jakarta-tomcat-4.1.12
manager.url=http://localhost:8080/manager
username=tomcatusername
password=tomcatpassword

You do not need to change the app.name parameter now. If you later reuse these files to create another Web application, you can change app.name to reflect the name of the new application. Assuming that you are using a Tomcat 4 instance running on your local machine, you should not need to change the manager.url parameter.

You will probably need to change the tomcat.home parameter to point at your Tomcat home directory. The above setting assumes that Tomcat 4.1.12 has been installed in the /usr/local directory. Ant uses this parameter to set up a CLASSPATH for compiling AddressBook's Java classes, with Tomcat's common/lib .jar files. (These .jar files are automatically available at runtime to both Tomcat and the Web application and do not need to be copied into the Web application's WEB-INF/lib directory.)

Tomcat has a similar directory: shared/lib. These .jar files are available at runtime to the Web application, but not to Tomcat itself.

You will need to change the tomcatusername and tomcatpassword parameters so that they match those in Tomcat's conf/tomcat-users.xml file. Ant uses these parameters, as well as manager.url, to establish its authority to install the AddressBook Web application into the Tomcat environment.

See build.properties for the complete, annotated source code.

AddressBook/build.xml

AddressBook/build.xml contains the Ant configuration data. build.xml implements many Ant "targets." Here are the more useful targets:

• ant build builds the Web application.
• ant install installs the Web application for testing.
• ant remove uninstalls the Web application.
• ant deploy permanently installs the Web application.
• ant undeploy permanently undeploys the Web application.

See build.xml for the complete, annotated source code.

AddressBook/context.xml

AddressBook/context.xml is installed into Tomcat by Ant when processing install, reload, remove, deploy, and undeploy requests. It contains the details of AddressBook's "context," or the parameters that Tomcat uses when executing AddressBook.

A Logger entry specifies that Tomcat should log AddressBook events into a text file stored in Tomcat's logs directory. Here is the Logger entry to name the log file localhost_AddressBook_log.YYYY-MM-DD.txt, where YYYY-MM-DD is the log's date:

<Logger className="org.apache.catalina.logger.FileLogger"
	prefix="localhost_AddressBook_log." suffix=".txt" timestamp="true"/>

A Resource entry, together with a ResourceParams entry, specifies that Tomcat should establish a javax.sql.DataSource named jdbc/Public for AddressBook. The following settings establish the javax.sql.DataSource as a org.apache.commons.dbcp.BasicDataSourceFactory class, the URL as jdbc:mysql://localhost:3306/Public?autoReconnect=true, a JDBC Driver Class of org.gjt.mm.mysql.Driver, a username of mysqlusername, and a password of mysqlpassword:

<Resource name="jdbc/Public" auth="Container" type="javax.sql.DataSource"/>

<ResourceParams name="jdbc/Public">

    <parameter>
        <name>factory</name>
        <value>org.apache.commons.dbcp.BasicDataSourceFactory</value>
    </parameter>

    <parameter>
        <name>url</name>
        <value>jdbc:mysql://localhost:3306/Public?autoReconnect=true</value>
    </parameter>

    <parameter>
        <name>driverClassName</name>
        <value>org.gjt.mm.mysql.Driver</value>
    </parameter>

    <parameter>
        <name>username</name>
        <value>mysqlusername</value>
    </parameter>

    <parameter>
        <name>password</name>
        <value>mysqlpassword</value>
    </parameter>

    ... [omitted] ...

</ResourceParams>

The above code creates the javax.sql.DataSource as part of the Web application's context. Alternatively, where the javax.sql.DataSource is to be used by more than one Web application, it may be defined as a global resource outside of the Web application's context with the Tomcat Administration software.

See context.xml for the complete, annotated source code.

AddressBook/src/*.java

The src directory contains the Web application's three Java classes. See Address.java, AddressesDB.java, and ContextListener.java for the complete, annotated source code.

AddressBook/web/*.jsp

The web directory contains the Web application's seven JSPs. See Home.jsp, RequestAdd.jsp, DoAdd.jsp, RequestDelete.jsp, DoDelete.jsp, RequestModify.jsp, and DoModify.jsp for the complete, annotated source code.

AddressBook/web/WEB-INF/web.xml

AddressBook/web/WEB-INF/web.xml is the Web application deployment descriptor for AddressBook. It contains two key parameters.

The listener parameter identifies the listener Java class AddressBook.ContextListener, which will be called during application startup and shutdown.

<listener>
   <listener-class>AddressBook.ContextListener</listener-class>
</listener>

The welcome-file-list parameter controls the entry point for AddressBook. The following code sets Home.jsp as AddressBook's only entry point.

<welcome-file-list>
   <welcome-file>Home.jsp</welcome-file>
</welcome-file-list>

See web.xml for the complete, annotated source code.

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