网络编程之:检查URL所指定的图片是否存在(转)

可以利用java.net.HttpURLConnection内的getResponseCode()去检查应答代码(Response Code)

Java代码

1. URL url = new URL( postURL );   
2. HttpURLConnection urlcon = (HttpURLConnection) url.openConnection( );   
3. urlcon.setRequestMethod("POST");   
4. urlcon.setRequestProperty("Content-type", "application/x-www-form-urlencoded");   
5. if ( urlcon.getResponseCode( ) != HttpURLConnection.HTTP_OK ) {   
6.     System.out.println("Posted ok!");   
7. } else {   
8.     System.out.println("Bad post...");   
9.     return;   
10. }  

URL url = new URL( postURL );HttpURLConnection urlcon = (HttpURLConnection) url.openConnection( );urlcon.setRequestMethod("POST");urlcon.setRequestProperty("Content-type", "application/x-www-form-urlencoded");if ( urlcon.getResponseCode( ) != HttpURLConnection.HTTP_OK ) {    System.out.println("Posted ok!");} else {    System.out.println("Bad post...");    return;}

Response Code在Java API Doc的HttpURLConnection有详细的定义，如上例的HTTP_OK。

常用的Response Code:
200 OK
400 Bad Request
401 Unauthorized
403 Forbidden
404 Not Found