java.net.ConnectException：错误号：110（连接超时）

Question

我正在尝试连接客户端服务器，在打开连接时遇到以下错误：

java.net.ConnectException: errno: 110 (Connection timed out), error: 
Connection timed out (local port XXXXX to address 0:0:0:0:0:0:0:0, remote 
port XXXX to address XXX.XXX.XXX.XX)

代码段：

URL url = new URL("http://XXX.XXX.XXX.XX:XXXX/services/ServiceEngine");

HttpURLConnection connection = (HttpURLConnection) url.openConnection();
connection.setDoOutput(true);
connection.setRequestMethod("POST");
connection.setRequestProperty("Content-Type", "application/json");

OutputStreamWriter writer = new OutputStreamWriter(connection.getOutputStream());
writer.write(json);
writer.close();
BufferedReader br = new BufferedReader(new InputStreamReader(connection.getInputStream()));
String line;
while ((line = br.readLine()) != null) {
  jsonString.append(line);
}
br.close();
connection.disconnect();

Answer 1

当服务器在预定时间段内无法响应并且服务器的代码逻辑关系不大时，就会发生连接超时。

您可以使用HttpURLConnection.setConnectTimeout（）更改此时间段，如下所示：

connection.setConnectTimeout(10000); //Time is set in milliseconds, so 1000 is 1 second. 

另外，正如另一位用户指出的那样，可能是您的服务器尚未真正启动并准备好托管连接。