java - Android:无法发送http post

Question

我一直在绞尽脑汁想弄清楚如何在 Android 中发送 post 方法。这是我的代码的样子:

public class HomeActivity extends Activity implements OnClickListener {

    private TextView textView;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        setContentView(R.layout.main);

        textView = (TextView) findViewById(R.id.text);
        Button button = (Button)findViewById(R.id.button);
        button.setOnClickListener(this);

    }

    @Override
    public void onClick(View view) {    
        HttpPost httpMethod = new HttpPost("http://www.example.com/");
        httpMethod.addHeader("Accept", "text/html");
        httpMethod.addHeader("Content-Type", "application/xml");


        AndroidHttpClient client = AndroidHttpClient.newInstance("Android");
        String result = null;
        try {
            HttpResponse response = client.execute(httpMethod);
            textView.setText(response.toString());

            HttpEntity entity = response.getEntity();

            Log.i(HomeActivity.class.toString(), result);
            textView.setText("Invoked webservice");
        } catch (IOException e) {
            e.printStackTrace();
            Log.e(HomeActivity.class.toString(), e.getMessage());
            textView.setText("Something wrong:" + e.getMessage());
        }
    }
}

这是我得到的异常:

I/ARMAssembler(   59): generated scanline__00000177:03515104_00001001_00000000 [
 91 ipp] (114 ins) at [0x334348:0x334510] in 1430659 ns
W/System.err(  272): java.net.UnknownHostException: www.example.com
W/System.err(  272):    at java.net.InetAddress.lookupHostByName(InetAddress.jav
a:513)
W/System.err(  272):    at java.net.InetAddress.getAllByNameImpl(InetAddress.jav
a:278)
W/System.err(  272):    at java.net.InetAddress.getAllByName(InetAddress.java:24
2)
W/System.err(  272):    at org.apache.http.impl.conn.DefaultClientConnectionOper
ator.openConnection(DefaultClientConnectionOperator.java:136)
W/System.err(  272):    at org.apache.http.impl.conn.AbstractPoolEntry.open(Abst
ractPoolEntry.java:164)
W/System.err(  272):    at org.apache.http.impl.conn.AbstractPooledConnAdapter.o
pen(AbstractPooledConnAdapter.java:119)
W/System.err(  272):    at org.apache.http.impl.client.DefaultRequestDirector.ex
ecute(DefaultRequestDirector.java:348)
W/System.err(  272):    at org.apache.http.impl.client.AbstractHttpClient.execut
e(AbstractHttpClient.java:555)
W/System.err(  272):    at org.apache.http.impl.client.AbstractHttpClient.execut
e(AbstractHttpClient.java:487)
W/System.err(  272):    at org.apache.http.impl.client.AbstractHttpClient.execut
e(AbstractHttpClient.java:465)
W/System.err(  272):    at android.net.http.AndroidHttpClient.execute(AndroidHtt
pClient.java:243)
W/System.err(  272):    at com.collaboapp.android.HomeActivity.onClick(HomeActiv
ity.java:152)
W/System.err(  272):    at android.view.View.performClick(View.java:2408)
W/System.err(  272):    at android.view.View$PerformClick.run(View.java:8816)
W/System.err(  272):    at android.os.Handler.handleCallback(Handler.java:587)
W/System.err(  272):    at android.os.Handler.dispatchMessage(Handler.java:92)
W/System.err(  272):    at android.os.Looper.loop(Looper.java:123)
W/System.err(  272):    at android.app.ActivityThread.main(ActivityThread.java:4
627)
W/System.err(  272):    at java.lang.reflect.Method.invokeNative(Native Method)
W/System.err(  272):    at java.lang.reflect.Method.invoke(Method.java:521)
W/System.err(  272):    at com.android.internal.os.ZygoteInit$MethodAndArgsCalle
r.run(ZygoteInit.java:868)
W/System.err(  272):    at com.android.internal.os.ZygoteInit.main(ZygoteInit.ja
va:626)
W/System.err(  272):    at dalvik.system.NativeStart.main(Native Method)
E/class android.HomeActivity(  272): www.example.com
D/ThrottleService(   59): finally have imsi - retreiving data
D/ThrottleService(   59): onPollAlarm - roaming =false, read =0, written =0, new
 total =0
D/SntpClient(   59): request time failed: java.net.SocketException: Address fami
ly not supported by protocol

我在这里做错了什么？我可能需要从 Android 模拟器配置什么才能让它正常工作吗？

感谢您的帮助。

Answer 1

似乎是 AndroidHttpClient 导致了该异常。你的例子会起作用

• 如果使用，请按照建议设置“INTERNET”权限
• 将“AndroidHttpClient”替换为“DefaultHttpClient”
• 删除行“Log.i(HomeActivity.class.toString(), result);”因为结果为空

我不清楚为什么这个类(class)没有按预期工作，也许有人可以解释一下。该线程也讨论了该问题，但也没有解释代码失败的原因:http://groups.google.de/group/android-developers/browse_thread/thread/cc59efb9475ac557/81116369f2c6bd7a?hl=de&lnk=gst&q=This+thread+forbids+HTTP+requests#81116369f2c6bd7a .