对于那些说@kuester2000的答案不起作用的人，请注意HTTP请求，首先尝试找到带有DNS请求的主机IP，然后向服务器发出实际的HTTP请求，因此您可能还需要为DNS请求设置超时。
如果你的代码没有超时的DNS请求，这是因为你能够到达DNS服务器或你正在击中Android DNS缓存。顺便说一下，您可以通过重新启动设备来清除这个缓存。
这段代码扩展了原始的答案，包括一个自定义超时的手动DNS查找:
//Our objective
String sURL = "http://www.google.com/";
int DNSTimeout = 1000;
int HTTPTimeout = 2000;
//Get the IP of the Host
URL url= null;
try {
url = ResolveHostIP(sURL,DNSTimeout);
} catch (MalformedURLException e) {
Log.d("INFO",e.getMessage());
}
if(url==null){
//the DNS lookup timed out or failed.
}
//Build the request parameters
HttpParams params = new BasicHttpParams();
HttpConnectionParams.setConnectionTimeout(params, HTTPTimeout);
HttpConnectionParams.setSoTimeout(params, HTTPTimeout);
DefaultHttpClient client = new DefaultHttpClient(params);
HttpResponse httpResponse;
String text;
try {
//Execute the request (here it blocks the execution until finished or a timeout)
httpResponse = client.execute(new HttpGet(url.toString()));
} catch (IOException e) {
//If you hit this probably the connection timed out
Log.d("INFO",e.getMessage());
}
//If you get here everything went OK so check response code, body or whatever
使用方法:
//Run the DNS lookup manually to be able to time it out.
public static URL ResolveHostIP (String sURL, int timeout) throws MalformedURLException {
URL url= new URL(sURL);
//Resolve the host IP on a new thread
DNSResolver dnsRes = new DNSResolver(url.getHost());
Thread t = new Thread(dnsRes);
t.start();
//Join the thread for some time
try {
t.join(timeout);
} catch (InterruptedException e) {
Log.d("DEBUG", "DNS lookup interrupted");
return null;
}
//get the IP of the host
InetAddress inetAddr = dnsRes.get();
if(inetAddr==null) {
Log.d("DEBUG", "DNS timed out.");
return null;
}
//rebuild the URL with the IP and return it
Log.d("DEBUG", "DNS solved.");
return new URL(url.getProtocol(),inetAddr.getHostAddress(),url.getPort(),url.getFile());
}
这个类来自这篇博客文章。如果你要用的话，去看看注释。
public static class DNSResolver implements Runnable {
private String domain;
private InetAddress inetAddr;
public DNSResolver(String domain) {
this.domain = domain;
}
public void run() {
try {
InetAddress addr = InetAddress.getByName(domain);
set(addr);
} catch (UnknownHostException e) {
}
}
public synchronized void set(InetAddress inetAddr) {
this.inetAddr = inetAddr;
}
public synchronized InetAddress get() {
return inetAddr;
}
}
