The Java Runtime Environment (JRE) and the Java Development Kit (JDK) are essential tools for both web and software developers. Typically, Oracle provides these installations as executable (EXE) or MSI installer packages. However, in some cases, developers or system administrators may prefer to have these tools packaged as ZIP files for various reasons, such as the need for manual installation or the requirement to use a specific version of Java on systems without administrative privileges.

Why Opt for ZIP over EXE or MSI?

1. Portability: ZIP files can be transferred and extracted on any compatible system without the need for special permissions.
2. Control: Extracting from a ZIP file allows for finer control over the installation process. You can choose exactly where to place your JRE or JDK files.
3. No Installation Required: By using ZIP files, no formal installation process is required, which means no entries are made in the system registry (on Windows systems), and no system-wide environmental variables are changed.
4. Multiple Versions: It's easier to maintain multiple versions of the JDK or JRE on the same system, handy for testing across different versions.

Obtaining JRE / JDK as ZIP

As of the latest updates from Oracle and other OpenJDK distributors like AdoptOpenJDK or Azul Systems, the process to get JDK or JRE as a ZIP file varies slightly. Below are stepwise approaches depending on the source:

1. Oracle JDK:

Oracle does not typically offer the JDK or JRE as a direct ZIP download for Windows. However, for macOS and Linux, tar.gz (similar to zip) archives are provided. For Windows, however, you may need to use tools to extract the installation files from the EXE.

Steps to extract JDK from an EXE:

• Download the JDK EXE file.
• Use tools like 7-Zip to open the EXE file as an archive.
• Extract the contents to your desired location.

2. AdoptOpenJDK (Adoptium):

AdoptOpenJDK provides OpenJDK binaries in a variety of packages, including ZIP files.

Steps to download:

• Visit the AdoptOpenJDK downloads page.
• Select the version you need.
• Choose “.zip” from the dropdown menu under the “Binary” header.

3. Azul Zulu JDK:

Azul’s Zulu JDK also provides ZIP file distributions.

Steps to download:

• Navigate to the Azul Zulu download page.
• Select your platform and version.
• Download the ZIP file format from the options provided.

Best Practices When Using ZIP Distributions

• Verify Hashes and Signatures: Always verify the downloaded ZIP file's integrity and authenticity through SHA256 sums or GPG signatures to ensure it has not been tampered with.
• Manage Java Versions: Use version management tools like jEnv or SDKMAN! for handling multiple Java versions if you regularly switch between them for different projects.
• Update PATH Manually: Since ZIP installations don’t touch environmental variables, you will need to manually update your system PATH to include the path to the bin directory of your JDK or JRE.

Summary Table

Conclusion

Using ZIP files for JRE or JDK can significantly ease the management and operation of Java applications, especially in environments requiring specific configurations or multiple versions. While it requires a bit more hands-on setup initially, the flexibility and control it offers can be well worth the effort. Always ensure to adhere to security and maintenance best practices, like frequent updates and checking for verified source downloads.