Sun Java System Web Server 6.1 SP9 Programmer's Guide

Chapter 1 Technology Overview

This chapter summarizes the various APIs and programming technologies supported by Sun Java System Web Server 6.1. More information about each API or programming technology is provided either in a chapter in this guide, or in a separate guide (reference information is provided).

This chapter has the following sections:

Sun Java System Web Server Architecture

Sun Java System Web Server incorporates a modular architecture that integrates seamlessly with all products in the Sun Java System family of servers. In addition, Sun Java System Web Server 6.1 supports a variety of APIs and programming technologies that enable you to do the following:

Sun Java System Web Server includes a number of software modules. These are discussed in the following topics:

Content Engines

Sun Java System Web Server content engines are designed for manipulating customer data. The following three content engines make up the web publishing layer of the Sun Java System Web Server architecture:

The HTTP engine represents the core of Sun Java System Web Server. From a functional perspective, the rest of the Sun Java System Web Server architecture resides on top of this engine for performance and integration functionality.

The Content Management engine enables you to manage the your content of the server. You create and store HTML pages, JavaServer Pages™ (JSP™) pages, and other files such as graphics, text, sound, or video on your server. When clients connect to your server they can view your files provided they have access to them.

The Search engine enables Sun Java System Web Server users to search the contents and attributes of documents on the server. As the server administrator you can create a customized text search interface that works with various types of document formats. Sun Java System Web Server converts many types of non-HTML documents into HTML as it indexes them, so users can use a web browser to view the documents that are found for their search.

Server Extensions

Sun Java System Web Server extensions enable you to extend or replace the function of the server. The following server extensions are part of the core Sun Java System Web Server architecture:

Common Gateway Interface (CGI) is a stand-alone application development interface that enables you to create programs that process your client requests dynamically.

Netscape Server Application Programming Interface (NSAPI) is used to implement the functions the server calls when processing a request (Server Application Functions or SAFs), which provide the core and extended functionality of Sun Java System Web Server. It allows the server’s processing of requests to be divided into small steps that may be arranged in a variety of ways for speed and flexible configuration.

Java Servlets and Java Server Pages extensions enable all servlet and JSP metafunctions, including instantiation, initialization, destruction, access from other components, and configuration management. Servlets and JSPs are reusable Java applications that run on a web server rather than in a web browser.

Runtime Environments

In addition to the various server extensions, Sun Java System Web Server includes a set of runtime environments that support the server extensions. These runtime environments include the following:

Application Services

Finally, the Sun Java System Web Server architecture includes a set of application services for various application-specific functions. These application services include the following:

Configuration Files

You can configure Sun Java System Web Server using the Administration user interfaces (UI), or by editing configuration files. Most of the configuration files are in the directory in the server_root/https-server_id/config directory. For example, if Sun Java System Web Server is installed on a Windows machine in C:\SunONE\Servers\, the configuration files for the server myserver.com are in:

C:\SunONE\Servers\https-myserver.com\config

The main configuration files are magnus.conf, server.xml, obj.conf, and mime.types. For more information about configuration files, see the Sun Java System Web Server 6.1 SP9 Administrator’s Configuration File Reference.

Sun Java System Web Server 6.1 APIs

This section summarizes the various APIs and programming technologies supported by Sun Java System Web Server 6.1, and describes how to get more information about them.

The main categories of extensions and modifications you can make to Sun Java System Web Server are listed below, and are used to do the following:

Server-parsed HTML Tags

Sun Java System Web Server 6.1 provides a C API for defining your own server-side tags. These tags can be used in addition to the standard server-side tags (such as config, include, and so on) in HTML files.

See Chapter 2, Server-parsed HTML Tags for more information about defining and using server-parsed tags.

CGI

Common Gateway Interface (CGI) programs run on the server and generate a response to return to the requesting client. CGI programs can be written in various languages, including C, C++, Java, and Perl, and as shell scripts. CGI programs are invoked through URL invocation.

Sun Java System Web Server complies with CGI specification version 1.1.

For more information about using CGI with Sun Java System Web Server 6.1, see Chapter 2, Server-parsed HTML Tags.

Java Servlets and JavaServer Pages (JSP)

Sun Java System Web Server 6.1 supports the Java™ Servlet 2.3 specification, including web application and WAR file (Web ARchive file) support, and the JavaServer Pages™ (JSP™) 1.2 specification.

Java servlets are server-side Java programs that can be used to generate dynamic content in response to client requests in much the same way as CGI programs. Servlets are accessed through URL invocation.

You create servlets using the Java Servlets API. Sun Java System Web Server 6.1 includes all of the files necessary for developing and running Java servlets. You can compile servlets using any Java compiler you like, as long as the webserv-ext.jar file is accessible to your Java compiler. The webserv-ext.jar file is in the server installation directory at:

/bin/https/jar

For information about using the Java Servlet API, see

http://java.sun.com/products/servlet/index.jsp

A JSP page is a page that can be viewed in a web browser, much like an HTML page. However, in addition to HTML tags, it can include a set of JSP tags and directives intermixed with Java code that extend the ability of the web page designer to incorporate dynamic content in a page. These additional features provide functionality such as displaying property values and using simple conditionals.

For more information about creating web applications that use servlets and JSPs on Sun Java System Web Server 6.1, see the Sun Java System Web Server 6.1 SP9 Programmer’s Guide to Web Applications.

For more information about using JavaServer Pages, see

http://java.sun.com/products/jsp/index.jsp

NSAPI

Netscape Server Application Programming Interface (NSAPI) is a set of C functions for implementing extensions to the server. These extensions are known as server plugins.

Using NSAPI you can write plugins to extend the functionality of Sun Java System Web Server. An NSAPI plugin defines one or more Server Application Functions (SAFs). You can develop SAFs for implementing custom authorization, custom logging, and for other ways of modifying how Sun Java System Web Server handles requests. For more information, see the Sun Java System Web Server 6.1 SP9 NSAPI Programmer’s Guide.

The obj.conf file contains instructions known as directives that instructs the server how to process requests received from clients. Each instruction is processed either during server initialization or during a particular stage of the request-handling process. Each instruction invokes an SAF.

For example, the following instruction is invoked when the request method is GET and the requested resource is of type text/html. This instruction calls the append-trailer function with a trailer argument of <H4><font color=green>Served by 6.1</font></H4>. The append-trailer function simply returns the requested resource to the client and appends the given trailer to it.


Service method=GET type="text/html" 
fn=append-trailer trailer="<H4>
<font color=green>Served by 6.1</font></H4>"

Sun Java System Web Server 6.1 comes with a set of predefined SAFs. It also comes with a library of NSAPI functions for developing your own SAFs to modify the way the server handles requests. For more information about predefined SAFs, see the Sun Java System Web Server 6.1 SP9 Administrator’s Configuration File Reference. For more information about custom SAFs, see the Sun Java System Web Server 6.1 SP9 NSAPI Programmer’s Guide.


Note –

The file obj.conf is essential for the operation of the server. If it does not exist, the server cannot work, because it has no instructions to handle requests.



Note –

When defining new SAFs, include the header function nsapi.h (which is in server_root/plugins/include) to provide access to all NSAPI functions.


Installing NSAPI Plugins (SAFs)

To load new NSAPI plugins containing customized SAFs into the server, add an Init directive to magnus.conf to load the shared library file that defines the new SAFs. This directive must call the load-modules function. This function takes the following arguments:

See the Sun Java System Web Server 6.1 SP9 NSAPI Programmer’s Guide for more information about the following topics:

Access Control API

The Access Control API is a C API that allows you to programmatically control accessibility on Sun Java System Web Server.

Access control lists (ACLs) determine the access privileges to the resources on the server. Each ACL contains a list of access control entries. The following access control entry, for example, specifies that all access is denied to everyone for any resource having a URI that starts with /private.


acl "uri=/private/*";
deny (all)
(user = "anyone");

To create access control lists, use the Restrict Access page in the Preferences tab of the Server Manager interface. You can also edit the files that contain the ACLs used by the server.

The default access control list resides in the directory server_root/httpacl. The default ACL file is generated.https-server_id.acl. There is also a file called genwork.https-server_id.acl that is a working copy the server uses until you save and apply your changes when working with the user interface. When editing the ACL file, you might want to work in the genwork file and then use the Server Manager to load and apply the changes.

With the Sun Java System Web Server 6.1, you can configure and reference multiple ACL files. For more information about configuring ACL files for virtual servers, see the Sun Java System Web Server 6.1 SP9 Administrator’s Guide.

With the Access Control API you can modify ACLs, read and write ACL files, and evaluate and test access to resources on the server.

You can also define your own attributes for authentication. For example, you can authenticate users based on e-mail address or on the URL that referred them to the resource:

allow (read) referer="*www.acme.com*"

You can also authenticate the client based on your own authentication methods and databases.

Registering New Authentication Services

To tell the server to use your attributes for authentication, you must define your own Loadable Authentication Service (LAS), which is an NSAPI plugin. You load it into the server in the usual manner by adding the following directives to magnus.conf:

Certificate-Mapping API

The Certificate-Mapping API consists of data structures and functions used to manage certificate mapping.

When a user authenticates to a Sun Java System server by sending a client certificate to the server, the server uses information in the certificate to search the user directory for the entry of the user.

You can configure some parts of this process by editing the file certmap.conf. This file specifies the following:

API Summary

The following table lists the APIs available in Sun Java System Web Server 6.1.

Table 1–1 APIs Available in Sun Java System Web Server 6.1

API/Interface/Protocol  

Language  

Documentation  

Interfaces for GeneratingDynamic Content

   

Custom Server-parsed HTML Tags 

Chapter 2, Server-parsed HTML Tags

Java Servlets 

Java 

Sun Java System Web Server 6.1 Programmer’s Guide to Web Applications

JavaServer Pages 

HTML with additional JSP tags 

Sun Java System Web Server 6.1 Programmer’s Guide to Web Applications

CGI (one process per request) 

C, C++, Perl, shell, and other languages 

The Common Gateway Interface:

http://hoohoo.ncsa.uiuc.edu/cgi/overview.html

APIs for Writing ServerPlugins

   

NSAPI (in-process shared object/DLL) 

C, C++ 

Sun Java System Web Server 6.1 NSAPI Programmer’s Guide

Access Control API

C, C++ 

Access Control Programmer’s Guide

Certificate-Mapping API 

C, C++ 

Certificate-Mapping Programmer’s Guide

Changes from Previous Versions

Changes from previous versions of Sun Java System Web Server are summarized in the following sections:

API Changes Since iPlanet Web Server 3.x

API Changes Since iPlanet Web Server 4.0

API Changes Since iPlanet Web Server 4.1

API Changes Since Sun Java System Web Server 6.0