Building a Custom Web Server

You may want to add additional features to the web server with your own servlets. This document discusses how to do this.

The build process relies on the Ant build tool from The Jakarta Project. A build.xml file is included, and the only file you need to modify for your own configuration is the file.

Subject Menu

Including Your Own Source

The build process allows you to include your own source. You will need to modify these build properties: src.paths, src.files, and possibly target.jar and dependency.classpath.

Place the location of the source files in src.paths, and a list of files in src.files. If your code depends on further libraries, you may need to modify dependency.classpath as well. See the build configuration section for more details.


Including Your Own Classes

There are no extra steps required to include your own libraries. They need to be copied to the SNAP and then added to the classpath when executing the server, but that's it.


Build Configuration — The File

The file is the only place you are required to manage your build configuration. The syntax requrements are only that a forward slash (/) for the file separator, and a colon (:) for the path separator, are used. Also, any non-required properties may be left unspecified.

Note: If you choose to use backslashes (\) for your paths, say, in Windows, then you must use pairs (eg. snap.path=C:\\Java\\snap1.0.6). This is because in properties files, backslashes are treated specially. They act to change the meaning of the following character. Please consult the Java documentation for more information.


This points to the location of the SNAP distribution. For example:


This property is required.


This points to the location of the preverify.exe program included in your SNAP distribution. For example:


This program is used to preprocess and check your classes before archiving them into a JAR. It is not necessary to preverify your classes, so it is okay to leave this property undefined.


This points to the location(s) of your source files. For example:


A path separator is used between different paths.


A comma- or space-separated list of source files. This may be specified using Ant-style wildcard patterns. For example:


It is not a good idea to specify **/*.java since that may include unwanted source files. Instead, be more specific with the package structure, as in the above example.


This specifies a CLASSPATH-like list of paths and archives containing classes needed for the build. Any SNAP-related library, such as the 1-Wire library, is automatically included in the SNAP classes, and does not need to be specified here. For example:



This names the JAR file that will be created from any compiled source code that was specified with src.files. If not specified, then the default will be "myclasses.jar".

This should not contain extra path information. For example:


These are incorrect: target.jar=path/mylib.jar or target.jar=/root/path/mylib.jar.

This file will be included by the deploy script.

One additional step you must do is prepend this file to the '-classpath' setting inside the WebServer script in the snap/bin/ directory. This will enable the virtual machine to find your classes.


Other Build-Related Files

This section discusses the other files needed in the build process.

The build.xml file

The build.xml file is the Ant build script. Its default task will automatically compile any source files you have specified, and then archive them into a JAR in the snap/bin/ directory.

By default, all compiled classes will be written to a directory named classes/. This can be changed by changing the javac.destination property to something else.