tresf/FindJava.ps1

## FindJava.ps1
# 2019 Tres Finocchiaro, Ed Resleff - CC0/Public Domain
# - Searches the system for Java
# - Looks for specified files or features (e.g. Commercial Features)

# Whether or not to show script debbuging information
$SHOW_DEBUG = $True;

# List of possible Java Runtime locations (including JDK) search locations
# Also traverses through 32-bit registry hive (WOW6432Node)
$JRE_SEARCH = @{
    # Windows-only
    "HKLM:\SOFTWARE\JavaSoft\Java Runtime Environment" = $null;
    "HKLM:\SOFTWARE\JavaSoft\Java Development Kit" = $null;
    "HKLM:\SOFTWARE\JavaSoft\JDK" = $null;
    # Mac-only
    "/usr/libexec/java_home" = $null;
    "/Library/Internet Plug-Ins/JavaAppletPlugin.plugin/Contents/Home" = $null;
    # Universal
    "PATH" = $null;
    "JAVA_HOME" = $null;
};

# Detect system-specific variables
If([System.Environment]::OSVersion.Platform -eq "Unix") {
    $SLASH = "/";
    $UNIX = $True;
    $NEWLINE = "`n";
    $SUFFIX = "";
} Else {
    $SLASH = "\";
    $UNIX = $False;
    $NEWLINE = "`r`n";
    $SUFFIX = ".exe";
}

# Wildcard for matching files in JavaHome\bin\, useful for inferring certain commercial features
$JAVA_MATCH = @("*.exe");
$jre_found = @();

# Make a human readable title
Function Titlize($title) {
    Write-Host ""
    Write-Host "".PadRight($title.Length + 4, "=");
    Write-Host "  $title";
    Write-Host "".PadRight($title.Length + 4, "=");
}

Function Debug($item, $color) {
    If($SHOW_DEBUG) {
        If($color -ne "" -and $color -ne $null) {
            Write-Host $item -ForegroundColor $color;
        } Else {
            Write-Host $item;
        }
    }
}

# Explodes a string array into a human-readble format
Function Explode($arr) {
    $exploded = "   [$NEWLINE";
    $arr | % { $exploded += "     =>'$_'$NEWLINE"};
    $exploded += "   ]$NEWLINE";
    $exploded;
}

# Gets the Java directory based on a registry key or environmental variable
Function GetJavaHome($key) {
    Debug "Looking for Java in $key...";
    # Continue on errors to avoid early script termination.  Change to "Stop" for debugging.
    $ErrorAction = "SilentlyContinue"
    If($UNIX -and $key -like "*/java_home" -and (Test-Path $key)) {
        # Use java_home utility on MacOS
        Debug " - $key was provided, calling it directly to find Java...";
        $javaHome = &$key;
    } ElseIf($UNIX -and $key -like "*/Internet Plug-Ins/*") {
        # Passthru for common MacOS directory
        Debug " - $key was provided, looking there...";
        $javaHome = $key;
    } ElseIf($key -notlike "HK*:\*") {
        # Treat as environmental variable
        Debug " - $key doesn't match known pattern; Assuming env var...";
        If ($key -eq "PATH") {
            $javaHome = (Get-Command java -ErrorAction $ErrorAction).Source;
            Debug " - PATH provided; Using absolute path: $javaHome";
            If($javaHome -ne "") {
                $javaHome = Split-Path -parent (Split-Path -parent $javaHome);
                Debug " - Calculated parent directory: $javaHome";
            }
        } Else {
            $javaHome = (Get-Item "env:$key" -ErrorAction $ErrorAction).Value;
            Debug " - $key provided; Using underlying value: $javaHome";
        }
    } Else {
        # Treat as registry key
        Debug " - $key is probably a registry key, traversing...";
        $ver = (Get-ItemProperty -Path $key -Name CurrentVersion -ErrorAction $ErrorAction).CurrentVersion;
        Debug " - Registry shows CurrentVersion=$ver";

        If($ver -ne "") {
            Debug " - Looking at $key\$ver JavaHome...";
            $javaHome = (Get-ItemProperty -Path "$key\$ver" -Name JavaHome -ErrorAction $ErrorAction).JavaHome;
            Debug " - Registry shows JavaHome=$javaHome";
        } Else {
            Debug " - CurrentVersion is blank; Cannot use.";
        }

        # Set repeast flag for 32-bit nodes
        # PowerShell sucks with recursion, so we have to recurse last
        $try32bit = ($key -notlike "*WOW6432Node*");
    }

    # Sanitize before adding it to the list
    # TODO: "/usr" may cause issues with macOS by propting to install JRE
    if ($javaHome -ne "" -and $javaHome -ne $null -and (Test-Path $javaHome)) {
        Debug " - Appending $javaHome to list of valid locations";
        $obj = New-Object -TypeName PSObject;
        $obj | Add-Member -MemberType NoteProperty -Name Path -Value $javaHome;
        $obj | Add-Member -MemberType NoteProperty -Name Version -Value (GetJavaVersion $javaHome);
        $obj;
    } Else {
        Debug " - JavaHome is empty or points to a missing location.  Skipping.";
    }

    If($try32bit) {
        Debug "   - Done but checking the 32-bit registry, just incase...";
        GetJavaHome $key.Replace("HKLM:\SOFTWARE\","HKLM:\SOFTWARE\WOW6432Node\");
    }
}

# Tries to parse the Java version from a path, returns as a System.Version object
Function GetJavaVersion($value) {
    # Parse java -version on Unix (can probably be used on Windows, needs testing
    # stderr needs to be redirected to stdout
    Debug "Calling java -version to parse version info...";
    $info = &$value$($SLASH)bin$($SLASH)java -version 2>&1;
    # assume it's first value in quotes, e.g. java version "11.0.0"
    Debug " - Found the following:";
    Debug "$info" yellow;
    Debug " - Assuming version is in double quotes, splitting:";
    $parts = "$info" -Split '"';
    Debug (Explode $parts) green;
    $part = $parts[1];
    Debug " - Grabbing item at index 1:";
    Debug "   $part" cyan;
    Debug " - Splitting $part on any non-digits to separate parts:";
    $digits = "$part" -Split "\D+" | Where({ $_ -ne "" });
    Debug (Explode $digits) green;
    If($digits[0] -eq "1") {
        Debug " - Stripping first digit because it's in old 1.x format...";
        # User newer Java formatting (8.0 instead of 1.8)
        $unused,$digits=$digits; # drop first element
        Debug (Explode $digits) green;
    }
    Debug " - Joining parts with periods and casting to [System.Version]:";
    $ver = [System.Version]($digits -Join ".");
    Debug "   $ver" magenta;
    $ver;
}

# Calls jcmd and returns a custom property
Function CheckCustomProperty($jcmd, $proc, $property) {
    If((&$jcmd $proc help) -contains "$property") {
        &$jcmd $proc $property;
    } Else {
        Write-Warning "`"$property`" was not found calling `"$jcmd`" $proc help"
    }
}

$JRE_SEARCH.Keys | % { $jre_found += (GetJavaHome $_) }

Titlize "Java found in the following locations"
# Remove duplicates
$jre_found = ($jre_found |Sort-Object -Property Path -Unique)
# Sort by version
$jre_found = ($jre_found |Sort-Object -Property Version -Descending)
$jre_found|Format-Table;

Debug "Looking for highest JDK version...";
$best = "NOT_FOUND";
$jre_found | % {
    $jcmdPath = "$($_.Path)$($SLASH)bin$($SLASH)jcmd$($SUFFIX)";
    If(Test-Path $jcmdPath) {
        Debug "- JDK found $_" yellow;
        $best = $_;
        Return;
    } Else {
        Debug "- This does not appear to be a JDK $_";
    }
};
Write-Host "`nUsing `"$($best.Path)`""

# List all files in \bin with "java" in the name
$jre_found | % {
    $dir = $_.Path;
    $files = @();
    $JAVA_MATCH | % {
        Titlize "Matching `"$_`" in `"$dir`"";
        $files += (Get-ChildItem -Path $dir$($SLASH)bin -Filter $_ -Recurse | %{ $_.BaseName });
        Write-Host $files;
    }
};

# Call jcmd from the highest JDK directory found
$jcmd = "$($best.Path)$($SLASH)bin$($SLASH)jcmd";
Titlize "Running `"$jcmd`" to get processes found"
# Take all PIDs that aren't spawned from jcmd itself :)
$pids = (& $jcmd -l).Split("`n") -notmatch "JCmd"

$procs = @();
$pids | % {
    # Get the PID of the Java process
    $proc = "$_".Split()[0];
    # Counter for displaying additional features
    $feat = 0;
    # Build an object containing the process info
    $obj = New-Object -TypeName PSObject
    # Get the PID
    $obj | Add-Member -MemberType NoteProperty -Name PID -Value $proc;
    # Get the path to the running JAR
    $obj | Add-Member -MemberType NoteProperty -Name Process -Value $_.Substring($proc.Length);
    # Get the path to the running Java executable
    $obj | Add-Member -MemberType NoteProperty -Name Path -Value (Get-Process -id $proc).Path;
    # Any additional features to check for
    $obj | Add-Member -MemberType NoteProperty -Name "Feature$($feat + 1)" -Value (CheckCustomProperty $jcmd $proc "VM.check_commercial_features");

    # Add object to list
    $procs += $obj;
};
$procs |Format-Table # echo everything to the screen
	# 2019 Tres Finocchiaro, Ed Resleff - CC0/Public Domain
	# - Searches the system for Java
	# - Looks for specified files or features (e.g. Commercial Features)

	# Whether or not to show script debbuging information
	$SHOW_DEBUG = $True;

	# List of possible Java Runtime locations (including JDK) search locations
	# Also traverses through 32-bit registry hive (WOW6432Node)
	$JRE_SEARCH = @{
	# Windows-only
	"HKLM:\SOFTWARE\JavaSoft\Java Runtime Environment" = $null;
	"HKLM:\SOFTWARE\JavaSoft\Java Development Kit" = $null;
	"HKLM:\SOFTWARE\JavaSoft\JDK" = $null;
	# Mac-only
	"/usr/libexec/java_home" = $null;
	"/Library/Internet Plug-Ins/JavaAppletPlugin.plugin/Contents/Home" = $null;
	# Universal
	"PATH" = $null;
	"JAVA_HOME" = $null;
	};

	# Detect system-specific variables
	If([System.Environment]::OSVersion.Platform -eq "Unix") {
	$SLASH = "/";
	$UNIX = $True;
	$NEWLINE = "`n";
	$SUFFIX = "";
	} Else {
	$SLASH = "\";
	$UNIX = $False;
	$NEWLINE = "`r`n";
	$SUFFIX = ".exe";
	}

	# Wildcard for matching files in JavaHome\bin\, useful for inferring certain commercial features
	$JAVA_MATCH = @("*.exe");
	$jre_found = @();

	# Make a human readable title
	Function Titlize($title) {
	Write-Host ""
	Write-Host "".PadRight($title.Length + 4, "=");
	Write-Host " $title";
	Write-Host "".PadRight($title.Length + 4, "=");
	}

	Function Debug($item, $color) {
	If($SHOW_DEBUG) {
	If($color -ne "" -and $color -ne $null) {
	Write-Host $item -ForegroundColor $color;
	} Else {
	Write-Host $item;
	}
	}
	}

	# Explodes a string array into a human-readble format
	Function Explode($arr) {
	$exploded = " [$NEWLINE";
	$arr \| % { $exploded += " =>'$_'$NEWLINE"};
	$exploded += " ]$NEWLINE";
	$exploded;
	}

	# Gets the Java directory based on a registry key or environmental variable
	Function GetJavaHome($key) {
	Debug "Looking for Java in $key...";
	# Continue on errors to avoid early script termination. Change to "Stop" for debugging.
	$ErrorAction = "SilentlyContinue"
	If($UNIX -and $key -like "*/java_home" -and (Test-Path $key)) {
	# Use java_home utility on MacOS
	Debug " - $key was provided, calling it directly to find Java...";
	$javaHome = &$key;
	} ElseIf($UNIX -and $key -like "/Internet Plug-Ins/") {
	# Passthru for common MacOS directory
	Debug " - $key was provided, looking there...";
	$javaHome = $key;
	} ElseIf($key -notlike "HK:\") {
	# Treat as environmental variable
	Debug " - $key doesn't match known pattern; Assuming env var...";
	If ($key -eq "PATH") {
	$javaHome = (Get-Command java -ErrorAction $ErrorAction).Source;
	Debug " - PATH provided; Using absolute path: $javaHome";
	If($javaHome -ne "") {
	$javaHome = Split-Path -parent (Split-Path -parent $javaHome);
	Debug " - Calculated parent directory: $javaHome";
	}
	} Else {
	$javaHome = (Get-Item "env:$key" -ErrorAction $ErrorAction).Value;
	Debug " - $key provided; Using underlying value: $javaHome";
	}
	} Else {
	# Treat as registry key
	Debug " - $key is probably a registry key, traversing...";
	$ver = (Get-ItemProperty -Path $key -Name CurrentVersion -ErrorAction $ErrorAction).CurrentVersion;
	Debug " - Registry shows CurrentVersion=$ver";

	If($ver -ne "") {
	Debug " - Looking at $key\$ver JavaHome...";
	$javaHome = (Get-ItemProperty -Path "$key\$ver" -Name JavaHome -ErrorAction $ErrorAction).JavaHome;
	Debug " - Registry shows JavaHome=$javaHome";
	} Else {
	Debug " - CurrentVersion is blank; Cannot use.";
	}

	# Set repeast flag for 32-bit nodes
	# PowerShell sucks with recursion, so we have to recurse last
	$try32bit = ($key -notlike "WOW6432Node");
	}

	# Sanitize before adding it to the list
	# TODO: "/usr" may cause issues with macOS by propting to install JRE
	if ($javaHome -ne "" -and $javaHome -ne $null -and (Test-Path $javaHome)) {
	Debug " - Appending $javaHome to list of valid locations";
	$obj = New-Object -TypeName PSObject;
	$obj \| Add-Member -MemberType NoteProperty -Name Path -Value $javaHome;
	$obj \| Add-Member -MemberType NoteProperty -Name Version -Value (GetJavaVersion $javaHome);
	$obj;
	} Else {
	Debug " - JavaHome is empty or points to a missing location. Skipping.";
	}

	If($try32bit) {
	Debug " - Done but checking the 32-bit registry, just incase...";
	GetJavaHome $key.Replace("HKLM:\SOFTWARE\","HKLM:\SOFTWARE\WOW6432Node\");
	}
	}

	# Tries to parse the Java version from a path, returns as a System.Version object
	Function GetJavaVersion($value) {
	# Parse java -version on Unix (can probably be used on Windows, needs testing
	# stderr needs to be redirected to stdout
	Debug "Calling java -version to parse version info...";
	$info = &$value$($SLASH)bin$($SLASH)java -version 2>&1;
	# assume it's first value in quotes, e.g. java version "11.0.0"
	Debug " - Found the following:";
	Debug "$info" yellow;
	Debug " - Assuming version is in double quotes, splitting:";
	$parts = "$info" -Split '"';
	Debug (Explode $parts) green;
	$part = $parts[1];
	Debug " - Grabbing item at index 1:";
	Debug " $part" cyan;
	Debug " - Splitting $part on any non-digits to separate parts:";
	$digits = "$part" -Split "\D+" \| Where({ $_ -ne "" });
	Debug (Explode $digits) green;
	If($digits[0] -eq "1") {
	Debug " - Stripping first digit because it's in old 1.x format...";
	# User newer Java formatting (8.0 instead of 1.8)
	$unused,$digits=$digits; # drop first element
	Debug (Explode $digits) green;
	}
	Debug " - Joining parts with periods and casting to [System.Version]:";
	$ver = [System.Version]($digits -Join ".");
	Debug " $ver" magenta;
	$ver;
	}

	# Calls jcmd and returns a custom property
	Function CheckCustomProperty($jcmd, $proc, $property) {
	If((&$jcmd $proc help) -contains "$property") {
	&$jcmd $proc $property;
	} Else {
	Write-Warning "`"$property`" was not found calling `"$jcmd`" $proc help"
	}
	}

	$JRE_SEARCH.Keys \| % { $jre_found += (GetJavaHome $_) }

	Titlize "Java found in the following locations"
	# Remove duplicates
	$jre_found = ($jre_found \|Sort-Object -Property Path -Unique)
	# Sort by version
	$jre_found = ($jre_found \|Sort-Object -Property Version -Descending)
	$jre_found\|Format-Table;

	Debug "Looking for highest JDK version...";
	$best = "NOT_FOUND";
	$jre_found \| % {
	$jcmdPath = "$($_.Path)$($SLASH)bin$($SLASH)jcmd$($SUFFIX)";
	If(Test-Path $jcmdPath) {
	Debug "- JDK found $_" yellow;
	$best = $_;
	Return;
	} Else {
	Debug "- This does not appear to be a JDK $_";
	}
	};
	Write-Host "`nUsing `"$($best.Path)`""

	# List all files in \bin with "java" in the name
	$jre_found \| % {
	$dir = $_.Path;
	$files = @();
	$JAVA_MATCH \| % {
	Titlize "Matching `"$_`" in `"$dir`"";
	$files += (Get-ChildItem -Path $dir$($SLASH)bin -Filter $_ -Recurse \| %{ $_.BaseName });
	Write-Host $files;
	}
	};

	# Call jcmd from the highest JDK directory found
	$jcmd = "$($best.Path)$($SLASH)bin$($SLASH)jcmd";
	Titlize "Running `"$jcmd`" to get processes found"
	# Take all PIDs that aren't spawned from jcmd itself :)
	$pids = (& $jcmd -l).Split("`n") -notmatch "JCmd"

	$procs = @();
	$pids \| % {
	# Get the PID of the Java process
	$proc = "$_".Split()[0];
	# Counter for displaying additional features
	$feat = 0;
	# Build an object containing the process info
	$obj = New-Object -TypeName PSObject
	# Get the PID
	$obj \| Add-Member -MemberType NoteProperty -Name PID -Value $proc;
	# Get the path to the running JAR
	$obj \| Add-Member -MemberType NoteProperty -Name Process -Value $_.Substring($proc.Length);
	# Get the path to the running Java executable
	$obj \| Add-Member -MemberType NoteProperty -Name Path -Value (Get-Process -id $proc).Path;
	# Any additional features to check for
	$obj \| Add-Member -MemberType NoteProperty -Name "Feature$($feat + 1)" -Value (CheckCustomProperty $jcmd $proc "VM.check_commercial_features");

	# Add object to list
	$procs += $obj;
	};
	$procs \|Format-Table # echo everything to the screen