错误源头：
HttpResponse response = httpClient.execute(httpget);
错误信息：
android.os.NetworkOnMainThreadExceptionat android.os.StrictMode$AndroidBlockGuardPolicy.onNetwork(StrictMode.java:1117)at java.net.InetAddress.lookupHostByName(InetAddress.java:385)at java.net.InetAddress.getAllByNameImpl(InetAddress.java:236)at java.net.InetAddress.getAllByName(InetAddress.java:214)at org.apache.http.impl.conn.DefaultClientConnectionOperator.openConnection(DefaultClientConnectionOperator.java:137)at org.apache.http.impl.conn.AbstractPoolEntry.open(AbstractPoolEntry.java:164)at org.apache.http.impl.conn.AbstractPooledConnAdapter.open(AbstractPooledConnAdapter.java:119)at org.apache.http.impl.client.DefaultRequestDirector.execute(DefaultRequestDirector.java:360)at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:555)at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:487)at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:465)
解决办法：
1. 4.0以上就不允许在UI线程里面进行网络，是涉及到url操作的时候，访问网络不能在主程序中运行
2. <uses-permission android:name="android.permission.INTERNET" />
参考：
首次测试android程序连接网络错误：