Add oieserver launcher script

[tonygermano]

This version of the script is a modified version of Mitch Gaffigan's script, which in turn was a bash port of my clojure app from #61.

This script is the main launcher for the Open Integration Engine (OIE) server. It prepares the Java environment and executes the server launcher JAR file.

The script automatically finds a compatible Java runtime (version 17+ by default) by searching for a valid executable in the following priority order:

1. The OIE_JAVA_PATH environment variable.
2. The -java-cmd directive in the oieserver.vmoptions file or included .vmoptions files. Must specify the path to the 'java' executable. This is the preferred way to declare the desired version for running the server and can be overridden by OIE_JAVA_PATH. Can be a relative path from the location of this script.
3. The JAVA_HOME environment variable.
4. The 'java' command available in the system's PATH.

It also parses the 'oieserver.vmoptions' file to configure JVM options, system properties (-D...), and classpath modifications.

Issue: #2

[mgaffigan]

lgtm. I don't think I've been in the codebase long enough to "request changes", but i am suggesting some in the review comments.

[pacmano1]

I think you need to fix the java check to handle 1.8.x (for a better error message)

[tonygermano]

I think you need to fix the java check to handle 1.8.x (for a better error message)

It won't change the error message, because it only reports that the given path does not meet the minimum requirement, not which version, if any, was found.

[kayyagari]

Tested on M2 with Java17.

[pacmano1]

I can agree to disagree. I think the version should be echoed when there's a problem, but will approve anyway.

[kayyagari]

@pacmano1 the script reported this error when I first ran with JAVA_HOME set to 1.8:

Warning: '/Library/Java/JavaVirtualMachines/zulu-8.jdk/Contents/Home/bin/java' is specified by the JAVA_HOME environment variable, which is not a valid Java executable of at least version 17. Ignoring. Warning: 'java' does not exist in your PATH or is not a valid Java executable of at least version 17. Error: Could not find a Java 17+ installation. Please configure -java-cmd in conf/custom.vmoptions, set OIE_JAVA_PATH, set JAVA_HOME, or ensure 'java' in your PATH is version 17 or higher.

Any other detail you would prefer in addition to this?.

[pacmano1]

It's fine

[mgaffigan]

See mgaffigan@a6cd2ef for some suggested changes. Documentation edited to be available to Get-Help.

Other suggestion would be to default based on the registry on windows. I don't know whether JAVA_HOME is set by most installers.

$registryJavaHome = `
    (Get-ItemProperty -LiteralPath 'HKLM:\SOFTWARE\JavaSoft\Java Development Kit' -ErrorAction SilentlyContinue -RegView Default).JavaHome -or `
    (Get-ItemProperty -LiteralPath 'HKLM:\SOFTWARE\JavaSoft\Java Development Kit' -ErrorAction SilentlyContinue -RegView 32Bit).JavaHome -or `
    (Get-ItemProperty -LiteralPath 'HKLM:\SOFTWARE\JavaSoft\Java Runtime Environment' -ErrorAction SilentlyContinue -RegView Default).JavaHome -or `
    (Get-ItemProperty -LiteralPath 'HKLM:\SOFTWARE\JavaSoft\Java Runtime Environment' -ErrorAction SilentlyContinue -RegView 32Bit).JavaHome

[mgaffigan]

See comments and suggested edits commit in mgaffigan@a6cd2ef.

Most are nits or concision. Only significant issue I see in the powershell rev is that the args passed to java should be a splat (@ not $) - not an implicit array to string, since that will not handle quotes.