Java 类到下载文件

Question

我正在尝试使用以下代码使用简单的java类下载文件：

用于下载文件的简单 java 类

它为我的网址提供了以下错误：

java.net.ConnectException: Connection refused: connect  
at java.net.PlainSocketImpl.socketConnect(Native Method)  
at java.net.PlainSocketImpl.doConnect(Unknown Source)  
at java.net.PlainSocketImpl.connectToAddress(Unknown Source)  
at java.net.PlainSocketImpl.connect(Unknown Source)  
at java.net.Socket.connect(Unknown Source)  
at java.net.Socket.connect(Unknown Source)  
at sun.net.NetworkClient.doConnect(Unknown Source)  
at sun.net.www.http.HttpClient.openServer(Unknown Source)  
at sun.net.www.http.HttpClient.openServer(Unknown Source)  
at sun.net.www.http.HttpClient.<init>(Unknown Source)  
at sun.net.www.http.HttpClient.New(Unknown Source)  
at sun.net.www.http.HttpClient.New(Unknown Source)  
at sun.net.www.protocol.http.HttpURLConnection.getNewHttpClient(Unknown Source)  
at sun.net.www.protocol.http.HttpURLConnection.plainConnect(Unknown Source)  
at sun.net.www.protocol.http.HttpURLConnection.connect(Unknown Source)  
at sun.net.www.protocol.http.HttpURLConnection.getOutputStream(Unknown Source)  
at Download.URLSetUp(Download.java:32)  
at Download.main(Download.java:16)  

请让我知道你们中是否有人有任何灵魂。

谢谢
斯内哈

Answer 1

从 Java 1.5 开始，您还可以将 java.net.Proxy 实例传递给 openConnection（） 方法：

//Proxy instance, proxy ip = 192.168.0.1 with port 8080  
Proxy proxy = new Proxy(Proxy.Type.HTTP, new InetSocketAddress("192.168.0.1", 8080));
URL url = new URL("http://www.sheldonbrown.com/web_sample1.html");
HttpURLConnection uc = (HttpURLConnection)url.openConnection(proxy);
uc.connect ();
OutputStreamWriter wr = new OutputStreamWriter(uc
              .getOutputStream());  
BufferedReader rd = new BufferedReader(new InputStreamReader(uc
                .getInputStream()));  

Answer 2

您与该 URL 没有连接。

您是否尝试过来自网络浏览器的URL？

也许您和该 URL 之间存在代理？

Answer 3

如果您的浏览器需要代理来访问此 URL，则您的应用程序也需要代理。

要为URLConnection设置代理，请查看此页面

这可能很简单，因为使用以下参数运行应用程序

java -Dhttp.proxyHost=myproxyserver.com -Dhttp.proxyPort=80 Download