powershell - 如何区分try catch语句中的Invoke-WebRequest异常（HTTP错误码）

Question

我创建了一个脚本，使用Invoke-WebRequestcmdlet 使用 PowerShell 脚本下载 Internet 上的特定文件。

我有 2 个我想处理的已知异常：404 和 429。

我目前正在使用try/catch声明：

try {
    Invoke-WebRequest -Uri $download_url -OutFile $srr_file
} catch {
    ...snip...
}

但是对于这两个错误，我有相同的代码，这不是我想做的：

try {
    Invoke-WebRequest -Uri $download_url -OutFile $srr_file
} catch [something here] {
    # Here the code I would like to write if the HTTP response is 404 File not found
    # Will certainly be a continue command
} catch [something here] {
    # Here the code I would like to write if the HTTP response is 429 Too many request
    # Will certainly be a sleep command for 1 hour
}

这里是两种情况下命令的输出：

错误 HTTP 404
Invoke-WebRequest：远程服务器返回错误：（404）未找到。
在行：1 字符：1
+ Invoke-WebRequest -Uri https://<censored> -Outfile test.txt
+ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ~~~~~~~~~~~~~~~~~~~~
    + CategoryInfo : InvalidOperation : (System.Net.HttpWebRequest:HttpWebRequest) [Invoke-WebRequest], WebException
    + FullyQualifiedErrorId：WebCmdletWebResponseException，Microsoft.PowerShell.Commands.InvokeWebRequestCommand

错误 HTTP 429
Invoke-WebRequest：远程服务器返回错误：(429) Too Many Requests。
在行：1 字符：1
+ Invoke-WebRequest -Uri "https://<censored> -Outfile test.txt
+ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ~~~~~~~~~~~~~~~~~~~~
    + CategoryInfo : InvalidOperation : (System.Net.HttpWebRequest:HttpWebRequest) [Invoke-WebRequest], WebException
    + FullyQualifiedErrorId：WebCmdletWebResponseException，Microsoft.PowerShell.Commands.InvokeWebRequestCommand

Answer 1

你可以这样做：

try 
{
    $response = Invoke-WebRequest -Uri $download_url -OutFile $srr_file
} 
catch 
{
    switch ($_.Exception.Response.StatusCode.Value__)
    {
        404 { 
            // Here´s the code I would like to write if the HTTP response is 404 File not found
            // Will certainly be a continue command            
            }
        429 {
            // Here´s the code I would like to write if the HTTP response is 429 Too many request
            // Will certainly be a sleep command for 1 hour 
            }
    }
}

由于抛出相同的异常，您将无法单独捕获它们。