这样做后,我得到这个代码：
long diff = 0;
long starttime = 0;
long endtime = 0;
try
{
starttime = System.currentTimeMillis();
conn.connect();
endtime = System.currentTimeMillis();
diff = endtime - starttime;
if (endtime <= starttime + conn.getConnectTimeout())
{
//Trying to read sourecode
InputStreamReader isrConn = new InputStreamReader(conn.getInputStream());
BufferedReader brConn = new BufferedReader(isrConn);
line = brConn.readLine();
while (line != null)
{
response += line + "\t";
try
{
line = brConn.readLine();
} catch (IOException e)
{
printError("Reading sourcecode Failed.");
}
}
}
else
{
response = "blabla.";
}
// If conn.connect Failed
} catch (IOException e)
{
endtime = System.currentTimeMillis();
diff = endtime - starttime;
response = "Message: "+e.getMessage() +" MyTimeout:"+ conn.getConnectTimeout() +" Actual time passed: "+ diff;
e.printStackTrace();
}
有连接可能会失败的原因,所以在很多情况下,我得到最后一个catch块并得到以下输出：
消息：连接超时：连接MyTimeout：40000实际通过时间：21012
消息：连接超时：连接MyTimeout：40000实际传递时间：21016
消息：连接超时：连接MyTimeout：40000通过的实际时间：21010
消息：连接超时：连接MyTimeout：40000通过的实际时间：21009
所以我的问题是：我将超时设置为40000毫秒,但是在大约21000毫秒之后我得到一个“连接超时” – 响应,你们有没有知道为什么呢？
编辑：im使用windows 7和我现在添加e.printStackTrace()到catch块,像注释中所说.感谢到目前为止.现在的输出是(示例)：
java.net.ConnectException: Connection timed out: connect
at java.net.DualStackPlainSocketImpl.waitForConnect(Native Method)
at java.net.DualStackPlainSocketImpl.socketConnect(Unknown Source)
at java.net.AbstractPlainSocketImpl.doConnect(Unknown Source)
at java.net.AbstractPlainSocketImpl.connectToAddress(Unknown Source)
at java.net.AbstractPlainSocketImpl.connect(Unknown Source)
at java.net.PlainSocketImpl.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$1.run(Unknown Source)
at sun.net.www.http.HttpClient$1.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at sun.net.www.http.HttpClient.privilegedOpenServer(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 TestThread.getSourcePage(TestThread.java:361)
at TestThread.aChecker(TestThread.java:216)
at TestThread.getNextProxy(TestThread.java:169)
at TestThread.getNextC(TestThread.java:157)
at TestThread.aChecker(TestThread.java:273)
at TestThread.getNextProxy(TestThread.java:169)
at TestThread.aChecker(TestThread.java:295)
at TestThread.getNextProxy(TestThread.java:169)
at TestThread.getNextC(TestThread.java:157)
at TestThread.run(TestThread.java:103)
at java.lang.Thread.run(Unknown Source)
Message: Connection timed out: connect MyTimeout:40000 Actual time passed: 21015
解决方法
最大的线索：你得到java.net.ConnectException
根据javadoc,java.net.ConnectException表示连接被远程拒绝,原因是没有进程在端口上侦听.
public class ConnectException extends SocketException Signals that an error occurred while attempting to connect a socket to a remote address and port. Typically,the connection was refused remotely (e.g.,no process is listening on the remote address/port)
您在HttpUrlConnection中配置的内容
连接的超时(给定远程端口接受连接).如果连接超时到期,您将获得java.net.SocketTimeoutException,而不是java.net.ConnectException.
那么是什么原因导致java.net.ConnectException？
我尝试了以下测试用例：
+------------+------------+----------------+------------------+---------------------------------+ | Valid Host | Valid Port | Valid Proxy IP | Valid Proxy Port | Exception | +------------+------------+----------------+------------------+---------------------------------+ #1 | yes | yes | -NA- | -NA- | -- none -- | #2 | yes | no | -NA- | -NA- | java.net.ConnectException | +------------+------------+----------------+------------------+---------------------------------+ #3 | yes | yes | yes | yes | -- none -- | #4 | yes | no | yes | yes | java.net.SocketTimeoutException | #5 | yes | yes | yes | no | java.net.ConnectException | +------------+------------+----------------+------------------+---------------------------------+
>案例#1,#3是所有配置正确的快乐路径
>在#4的情况下,我们得到一个java.net.SocketTimeoutException,因为java进程能够建立连接(到代理端口),但是没有任何数据读取,因为目标主机的端口号无效
>如果#2,#5,我们得到java.net.ConnectException,因为java进程尝试写入/读取的端口无效
>连接超时值对于Java进程尝试连接的端口没有进程监听的情况并不适用.这就是为什么在超时到期之前得到ConnectException的原因
消息：连接拒绝：连接MyTimeout：10000实际传递时间：6549
java.net.ConnectException：Connection refused：connect
在java.net.DualStackPlainSocketImpl.waitForConnect(本机方法)
在java.net.DualStackPlainSocketImpl.socketConnect(DualStackPlainSocketImpl.java:85)
….
….
结论：
>您尝试连接的某些代理必须关闭.因此java进程抛出java.net.ConnectException>最好抓住java.net.ConnectException并将代理标记为invalid / down
