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HTTP Client in Apache return "Target host must not be null"

Posted on 2009-06-29
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Last Modified: 2013-12-06
Dear experts,
I am using Apache HTTP client library for Android emulator.
http://hc.apache.org/httpcomponents-client/httpclient/apidocs/org/apache/http/client/package-summary.html

However whenever I enter e.g "www.google.com" or "http://www.google.com", it always return error "Target host must not be null"
But when i convert into IP Address, all works well.
Would you be able to advice?

Thanks!
public void run() {
			Log.i("GList", "downloadProcess run()");
			props = new Properties();
 
			try {
				String url;
				url = "http://www.google.com"; //THIS IS FAILED
				//url = "http://216.239.61.104"; // THIS IS OK
				HttpManager.doGet(url, props);
			} catch (Exception e) {
				// TODO Auto-generated catch block
				e.printStackTrace();
			}
			// TODO Auto-generated method stub
		}

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Question by:isuhendro
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5 Comments
 
LVL 86

Expert Comment

by:CEHJ
ID: 24743483
>>HttpManager.doGet(url, props);

What's that? It's not Apache HttpClient..
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Author Comment

by:isuhendro
ID: 24743532
Hi CEHJ,
HttpManager just a wrapper of Apache HTTP client, please refer to the static method inside HttpManager below.
	public static String doGet (String serviceEndpoint, Properties props) throws Exception
	{
		HttpClient httpClient = new DefaultHttpClient();
		StringBuilder uriBuilder = new StringBuilder(serviceEndpoint);
		StringBuffer sbResponse = new StringBuffer ();		
		Enumeration<Object> enumProps = props.keys();
		String key, value = null;
		
		if (enumProps.hasMoreElements()) uriBuilder.append('?');
		while (enumProps.hasMoreElements())
		{
			key = (String)enumProps.nextElement();
			value = (String)props.get(key);
			uriBuilder.append(key);
			uriBuilder.append('=');
			uriBuilder.append(java.net.URLEncoder.encode(value));
			uriBuilder.append('&');			
		}
		HttpGet request = new HttpGet(uriBuilder.toString());
		
	HttpResponse response = httpClient.execute(request);
 
		

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CEHJ earned 125 total points
ID: 24743600
>>But when i convert into IP Address, all works well.

Sounds like a DNS error. Have you tried running your code on another network?
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Author Closing Comment

by:isuhendro
ID: 31598185
hi CEHJ,

thank you for your suggestion.
somehow this line java.net.URLEncoder gave invalid form URL
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LVL 86

Expert Comment

by:CEHJ
ID: 24949148
:-)
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