配置Heroku监听指定端口并验证inet PDFC SDK远程可用性

Got it, let's work through getting your PDFC SDK running properly on Heroku. The core issue here is that Heroku doesn't allow hardcoded ports like 9900—it uses dynamic port assignment via an environment variable. Here's how to adjust your setup:

1. Understand Heroku's Port Requirement #

Heroku assigns a unique port to your application at runtime, exposed via the PORT environment variable. Your app must listen to this port instead of 9900, otherwise Heroku won't route external traffic to your embedded server.

2. Check if PDFC SDK Supports Custom Port Configuration #

First, verify if your PDFC.jar accepts a command-line argument to specify the port. Look through the SDK's documentation or run:

java -jar PDFC.jar --help

Common flags for port configuration are -port, --port, or -p. For example, if the flag is -port, your startup command would use $PORT (the Heroku environment variable) instead of 9900.

3. Create a Procfile for Heroku #

Heroku uses a Procfile to define how your app starts. Create a file named Procfile (no file extension) in your project root with this line:

web: java -jar PDFC.jar -port $PORT -host 0.0.0.0

• The web process type tells Heroku this is the process that handles HTTP traffic.
• -host 0.0.0.0 ensures the server binds to all network interfaces (not just localhost), which is required for external access on Heroku. If your SDK uses a different flag for the host (like --bind), substitute that here.

4. Test Locally First #

Before deploying, test the setup on your local machine to confirm it works:

1. Set the PORT environment variable:
   • On macOS/Linux: export PORT=5000
   • On Windows (PowerShell): $env:PORT=5000
2. Run the startup command:

   java -jar PDFC.jar -port $PORT -host 0.0.0.0
   

3. Verify the server is listening on port 5000 (e.g., use curl http://localhost:5000 or check your system's network tools).

5. Deploy and Verify on Heroku #

• Push your updated code (including the Procfile) to Heroku.
• After deployment, check the logs to confirm the server is listening on the correct port:

  heroku logs --tail
  

  You should see a message like "Waiting for plain client requests on port [dynamic-port-number]" instead of 9900.

6. Note About Trial Version Restrictions #

Keep in mind that some trial SDKs may have restrictions on remote access (e.g., forcing binding to localhost). If you still can't connect after following the steps above, check the trial license terms or reach out to the SDK provider to confirm remote deployment is allowed.

内容的提问来源于stack exchange，提问作者lambad