Past versions of Web Proxy Server were delivered in two ways:
File-based format, packed in a ZIP distribution
Package-based format, included in past Java ES releases
To support these past practices, Web Proxy Server provides three upgrade paths to version 4.0.11:
Upgrading from a File-Based ZIP Distribution of Web Proxy Server 4.x
Upgrading from a Package-Based Distribution of Web Proxy Server 4.x
This installation program provided with Web Proxy Server 4.0.11 can identify and upgrade Web Proxy Server file-based installations back to version 4.0.
To upgrade a Web Proxy Server 4.x file-based installation using the Web Proxy Server 4.0.11 installer, see Chapter 1, Installing Sun Java System Web Proxy Server, in Sun Java System Web Proxy Server 4.0.11 Installation and Migration Guide.
To upgrade from the package-based distribution of Web Proxy Server 4.0.1 (in Java ES 2005Q4), 4.0.4 (in Java ES 5) or 4.0.5 (in Java ES 5 Update 1) to version 4.0.11, apply the patches for the appropriate platform, as described in Upgrade Support in Sun Java System Web Proxy Server 4.0.11 Release Notes.
Note that the upgraded installation is not exactly equivalent to installing the file-based ZIP distribution of version 4.0.11 because it represents a package-based upgrade, not a file-based installation.
Web Proxy Server does not support a direct upgrade to version 4.0.11 from versions prior to 4.0. Instead, follow the instructions provided in Chapter 3, Migrating From Version 3.6, in Sun Java System Web Proxy Server 4.0.11 Installation and Migration Guide.