连接超时：连接

Question

我收到连接超时：java 代码中的连接异常，请参见下文。 我已经在谷歌搜索但没有得到太多帮助，你可以在你的机器上运行这个代码，我在下面给出它的完整代码。 代码-

public class download {
    // final static int size=1024;

    public static void downloadValuationPDFReport() {
        OutputStream outStream = null;
        URLConnection uCon = null;
        InputStream is = null;
        String fAddress = null;
        URL Url = null;
        String localFileName = "abc.zip";
        String destinationDir = "H:\\";//"C:\\Users\\501301605\\Downloads";
        try {
            fAddress = "http://www.novell.com/coolsolutions/tools/downloads/ntradping.zip";
            byte[] buf;
            int byteRead = 0;
            Url = new URL(fAddress);
            outStream = new BufferedOutputStream(new FileOutputStream(destinationDir + "\\" + localFileName));
            uCon = Url.openConnection();
            is = uCon.getInputStream();
            buf = new byte[1024];
            while ((byteRead = is.read(buf)) != -1) {
                outStream.write(buf, 0, byteRead);
            }
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            try {
                is.close();
                outStream.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }
}

Answer 1

很可能您所在的网络不允许您直接连接到任何端口 80；尝试：

telnet www.novell.com 80

看看你是否得到答案；这也可能会导致超时。

您很可能需要使用代理（例如，请参阅here）。此外，您的代码使许多资源悬而未决，并且您使用已过时的File。

下面是如何用现代代码做到这一点：

final Path dstfile = Paths.get("h:", "abc.zip");

// ...

try (
    final InputStream in = url.openStream();
) {
    Files.copy(in, dstfile, StandardOpenOption.CREATE_NEW);
}