在使用http请求server时常常要传递一些参数给server，如IMEI号、平台号、渠道号、客户端的版本号等一些通用信息，像这些参数我们没有必要每次都拼在url后，我们可以统一添加到http头里。

1.HttpClient的设置http头的参数

	 HttpClient httpclient = new DefaultHttpClient();

	 httpclient.getParams().setParameter(
	 CoreConnectionPNames.CONNECTION_TIMEOUT, CONN_TIME_OUT);
	 HttpGet httpget = new HttpGet(url);
	 httpget.addHeader("version", SystemInfo.getVersionChars());
	 httpget.addHeader("client_token", SystemInfo.getIMEI());
	 httpget.addHeader("platform", SystemInfo.getPlatForm() + "");
	 httpget.addHeader("channel_id", SystemInfo.getChannelId() + "");

2.HttpURLConnection的设置http头的参数

httpURLConnection.addRequestProperty("version",
				SystemInfo.getVersionChars());
		httpURLConnection.addRequestProperty("client_token",
				SystemInfo.getIMEI());
		httpURLConnection.addRequestProperty("platform",
				SystemInfo.getPlatForm() + "");
		httpURLConnection.addRequestProperty("channel_id",
				SystemInfo.getChannelId() + "");

	httpURLConnection.setRequestProperty("version",
				SystemInfo.getVersionChars());
		httpURLConnection.setRequestProperty("client_token",
				SystemInfo.getIMEI());
		httpURLConnection.setRequestProperty("platform",
				SystemInfo.getPlatForm() + "");
		httpURLConnection.setRequestProperty("channel_id",
				SystemInfo.getChannelId() + "");

Android如何在http头信息里设置参数