This creates a parameterized PowerShell function for compiling and running Java applications in .java files.

Java-CompileRun.ps1

function Java-CompileRun {
  Param(
    [Parameter(Mandatory=$true)]
    [String]
  $javaFile,
	[Parameter(Mandatory=$false)]
    [String]
    $path=$PWD,
	[Parameter(Mandatory=$false)]
    [String]
    $jdkPath=$($(where.exe javac) -replace '\\[^\\]+$','')  
)
$path = $path -replace '\\$',''
$jdkPath = $jdkPath -replace '\\$',''
if (-not (Test-Path -Path "$path\$javaFile") -and (Test-Path -Path "$path\$javaFile.java")) {
  $javaFile = "$javaFile.java"
}
$quit = $false;
if(-not (Test-Path -Path "$jdkPath\javac.exe")){Write-Error -Message "Cannot find javac.exe at $jdkPath." -Category ObjectNotFound  -RecommendedAction "Please ensure you are providing the correct path to the JDK bin directory"; $quit = $true;}
if(-not (Test-Path -Path "$jdkPath\java.exe")){Write-Error -Message "Cannot find java.exe at $jdkPath." -Category ObjectNotFound  -RecommendedAction "Please ensure you are providing the correct path to the JDK bin directory"; $quit = $true;}
if(-not (Test-Path -Path "$path\$javaFile")) {Write-Error -Message "Cannot find $javaFile at $path\$javaFile." -Category ObjectNotFound  -RecommendedAction "Please ensure you are providing the correct path and the correct filename to the .java file"; $quit = $true; }
if($quit){return}

	$_javac = Start-Process -FilePath "$($jdkPath)\javac.exe" -ArgumentList "-Xlint:all $javaFile" -WorkingDirectory $Path  -NoNewWindow -PassThru -Wait
    if($_javac.ExitCode -eq 0){
      $_java = Start-Process -FilePath "$($jdkPath)\java.exe" -ArgumentList "$($javaFile -replace '.java','')" -WorkingDirectory $path  -NoNewWindow -PassThru -Wait
    }
}