http://blog.csdn.net/java2000_net/article/details/3723358

從 ftpClient的官方網的FAQ里面看到，實現這個需要用一個 自定義的SocketFactory
然后實現里面的 createSocket方法，有好多個。
http://wiki.apache.org/jakarta-commons/Net/FrequentlyAskedQuestions

原文如下：

Q: How can I set a connection timeout?

A: setDefaultTimeout does not set the connect timeout. It provides a default socket timeout. Only in J2SE 1.4 was the ability to specify a timeout on connect added to the Socket API. Since Commons Net 1.2.x has a J2SE 1.2 compatibility requirement, the ability to specify a connect timeout is not included. The way to workaround this is to implement your own SocketFactory and set it with SocketClient.setSocketFactory (FTPClient is a subclass of SocketClient). When you implement the SocketFactory, add a setConnectTimeout method or some such. Inside of the createSocket methods, use the J2SE 1.4 connect method with the timeout. We could actually provide socket factory that subclasses DefaultSocketFactory to do this without breaking backward compatibility, but that would have to be discussed further. The way to do it is to compile it only if J2SE >= 1.4 is being used. SocketClient could check for availability of the J2SE 1.4 connect method and instantiate the J2SE >= 1.4 factory if available (using Class.forName and newInstance). The setDefaultTimeout method could then be changed to also set the connect timeout in the new factory if being used. If users want this functionality enough, the best chance of getting it implemented soon is to submit a patch.

不過我看了 ftpClient 2.0的源代碼。

?ftpClient.connect(hostName, 21);

看看 connect的代碼如下
??? public void connect(String hostname, int port)
??? throws SocketException, IOException
??? {
??????? _socket_= _socketFactory_.createSocket();
??????? _socket_.connect(new InetSocketAddress(hostname, port), connectTimeout);
???????
??????? _connectAction_();
??? }

其中有一個connectTimeout正是我們需要的連接超時，我們看看它的定義
??? /** The socket's connect timeout (0 = infinite timeout) */
??? private static final int DEFAULT_CONNECT_TIMEOUT = 0;
??? protected int connectTimeout = DEFAULT_CONNECT_TIMEOUT;

可見默認是不限超時的。再搜索一下，找到如下這個方法
??? /**
???? * Sets the connection timeout in milliseconds, which will be passed to the {@link Socket} object's
???? * connect() method.
???? * @param connectTimeout The connection timeout to use (in ms)
???? * @since 2.0
???? */
??? public void setConnectTimeout(int connectTimeout) {
??????? this.connectTimeout = connectTimeout;
??? }
???
??? /**
???? * Get the underlying socket connection timeout.
???? * @return
???? * @since 2.0
???? */
??? public int getConnectTimeout() {
??????? return connectTimeout;
??? }
???
可見，我們完全可以直接設置超時時間就行了。具體代碼如下：

?FTPClient ftpClient = new FTPClient();
?ftpClient.setConnectTimeout(1000); // 一秒鐘，如果超過就判定超時了
?ftpClient.connect(hostName, 21);


估計2,0這個版本對這個問題進行了完善和增強，可以這么簡單的實現了。

?

http://www.docjar.com/html/api/examples/FTPSExample.java.html

總結

以上是生活随笔為你收集整理的ftpClient的连接超时设置(setConnectTimeout,setSoTimeout)的全部內容，希望文章能夠幫你解決所遇到的問題。

如果覺得生活随笔網站內容還不錯，歡迎將生活随笔推薦給好友。