Implemented #32 A discovery search feature for java.exe

src/jenv-autoscan.psm1

@@ -0,0 +1,61 @@
+function Invoke-AutoScan {
+    param (
+        [Parameter(Mandatory = $true)][object]$config,
+        [Parameter(Mandatory = $true)][boolean]$help,
+        [string]$path
+    )
+
+    if ($help) {
+        Write-Host '"jenv autoscan <path>"'
+        Write-Host 'This will search for any java.exe files in the given path and prompt the user to add them to JEnv'
+        Write-Host '<path> is the path to search like "C:\Program Files\Java"'
+        Write-Host 'If <path> is not provided, JEnv will search the entire system'
+        return
+    }
+
+    $paths = @($path)
+    if ( $path -eq "") {
+        # Get Drives including Temp folders
+        $drives = Get-PSDrive -PSProvider FileSystem | Select-Object -ExpandProperty Root
+        # Only keep the physical drive letter
+        $drives = $drives | ForEach-Object { $_.Substring(0, 3) }
+        # Only keep unique
+        $paths = $drives | Select-Object -Unique
+    }
+    # Check if the provided path exists
+    elseif (!(Test-Path -Path $path -PathType Container)) {
+        Write-Host "The provided path does not exist"
+        return
+    }
+
+    # Iterate over paths and find java.exe
+    Write-Host "JEnv is now searching for java.exe on your Computer. This could take some time..."
+    $javaExecutables = @()
+    foreach ($path in $paths) {
+        $path = $path + "\\"
+        $files = Get-ChildItem -Path $path -Recurse -File -ErrorAction "SilentlyContinue" | Where-Object { $_.FullName.EndsWith("\bin\java.exe") }
+        if ($null -ne $files) {
+            $files | ForEach-Object {
+                $javaExecutables += $_.FullName
+            }
+        }
+    }
+
+    # Filter out jenv tests java.exe
+    $root = (get-item $PSScriptRoot).parent.fullname
+    $javaExecutables = $javaExecutables | Where-Object { $_.Contains($root) -eq $false }
+
+    # Ask user if java.exe should be added to the list
+    foreach ($java in $javaExecutables) {
+        $version = Get-JavaVersion $java
+        switch (Open-Prompt "JEnv autoscan" ("Found java.exe at {0}. Default name is: '{1}'. Do you want to add it to the list?" -f $java, $version) "Yes", "No", "Rename" ("This will add {0} with alias '{1}' to JEnv" -f $java, $version), ("Skip {0}" -f $java), "Change the default name" 1) {
+            0 {
+                Invoke-Add $config $false $version ($java -replace "\\bin\\java\.exe$", "")
+            }
+            2 {
+                Invoke-Add $config $false (Read-Host ("Enter the new name for {0}" -f $java)) ($java -replace "\\bin\\java\.exe$", "")
+            }
+        }
+    }
+
+}

src/jenv.ps1

@@ -18,7 +18,7 @@ param (
     "jenv use <name>"           Applys the given Java-Version locally for the current shell
     "jenv local <name>"         Will use the given Java-Version whenever in this folder. Will set the Java-version for all subfolders as well
     #>
-    [Parameter(Position = 0)][validateset("list", "add", "change", "use", "remove", "local", "getjava", "link", "uninstall")] [string]$action,
+    [Parameter(Position = 0)][validateset("list", "add", "change", "use", "remove", "local", "getjava", "link", "uninstall", "autoscan")] [string]$action,
 
     # Displays this helpful message
     [Alias("h")]
@@ -42,6 +42,7 @@ Import-Module $PSScriptRoot\jenv-local.psm1 -Force
 Import-Module $PSScriptRoot\jenv-getjava.psm1 -Force
 Import-Module $PSScriptRoot\jenv-link.psm1 -Force
 Import-Module $PSScriptRoot\jenv-uninstall.psm1 -Force
+Import-Module $PSScriptRoot\jenv-autoscan.psm1 -Force
 #endregion
 
 #region Installation
@@ -128,6 +129,7 @@ if ($help -and $action -eq "") {
     Write-Host '"jenv local <name>"         Will use the given Java-Version whenever in this folder. Will set the Java-version for all subfolders as well'
     Write-Host '"jenv link <executable>"    Creates shortcuts for executables inside JAVA_HOME. For example "javac"'
     Write-Host '"jenv uninstall <name>"     Deletes JEnv and restores the specified java version to the system. You may keep your config file'
+    Write-Host '"jenv autoscan ?<path>?"    Will scan the given path for java installations and ask to add them to JEnv. Path is optional'
     Write-Host 'Get help for individual commands using "jenv <list/add/remove/change/use/local> --help"'
 }
 else {
@@ -143,7 +145,8 @@ else {
         local { Invoke-Local $config $help @arguments }
         getjava { Get-Java $config }
         link { Invoke-Link $help @arguments }
-        uninstall { Invoke-Uninstall $help $config @arguments }
+        uninstall { Invoke-Uninstall $config $help @arguments }
+        autoscan { Invoke-AutoScan $config $help @arguments }
     }
 
     #region Save the config

src/util.psm1

@@ -13,4 +13,13 @@ function Open-Prompt {
     }
 
     return $Host.UI.PromptForChoice($title, $question, $options, $default_choice)
+}
+
+function Get-JavaVersion {
+    param (
+        [Parameter(Mandatory = $true)][string]$javaexe
+    )
+    $version = (Get-Command $javaexe | Select-Object -ExpandProperty Version).toString()
+    $version = $version -replace "(?>\.0)*(?!.+)", "" # Remove trailing zeros
+    return $version
 }