android - Trying to send post to server but app keeps dying

Question

Hello I am trying to create a app that send out a variable to server but it keep dying when I try to send the response to a server

here is the code

 package com.example.door;

  import java.io.IOException;
  import java.io.UnsupportedEncodingException;
  import java.util.ArrayList; 
  import java.util.List;
  import org.apache.http.NameValuePair;
  import org.apache.http.client.ClientProtocolException;
 import org.apache.http.client.HttpClient; 
 import org.apache.http.client.entity.UrlEncodedFormEntity;
 import org.apache.http.client.methods.HttpPost;
import org.apache.http.impl.client.DefaultHttpClient;
import org.apache.http.message.BasicNameValuePair;

import android.os.Bundle;
import android.app.Activity;
import android.util.Log;
import android.view.Menu;
import android.view.View;
import android.widget.Button;
public class MainActivity extends Activity {
    Button opendoor;
    Button closedoor;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        // Make Object for Buttons
        //  sendButton = (Button) findViewById(R.id.sendButton);
            Button openbutton = (Button) findViewById(R.id.openButton);
        Button  closebutton = (Button) findViewById(R.id.closeButton);

    }
    //When the send button is clicked
    public void open(View v)
    {
        String server ="http://devel.foo.bar/04r0450240";
        HttpClient httpclient = new DefaultHttpClient();
        HttpPost httppost =new HttpPost(server);
        try{
            List<NameValuePair> nameValuePairs = new ArrayList<NameValuePair>(1);
            nameValuePairs.add(new BasicNameValuePair("led", "1"));
            httppost.setEntity(new UrlEncodedFormEntity(nameValuePairs));

            try {
                httpclient.execute(httppost);
            } catch (UnsupportedEncodingException e) {
                e.printStackTrace();
            }
         } catch (IOException e) {
             // TODO Auto-generated catch block
             Log.i("HTTP Failed", e.toString());
         }            

         return;
     }



    public void close(View v){

     HttpClient httpclient = new DefaultHttpClient();
        HttpPost httppost = new HttpPost("http://devel.foo.bar/04r0450240");

        try {
            List<NameValuePair> nameValuePairs = new ArrayList<NameValuePair>(1);
               nameValuePairs.add(new BasicNameValuePair("led", "0"));
               httppost.setEntity(new UrlEncodedFormEntity(nameValuePairs));
               httpclient.execute(httppost);
        } catch (ClientProtocolException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.main, menu);
        return true;
    }

}

Error 11-01 03:55:04.622: E/AndroidRuntime(1612): 11-01 03:55:04.622: E/AndroidRuntime(1612): 11-01 03:55:04.622: E/AndroidRuntime(1612): 11-01 03:55:04.622: E/AndroidRuntime(1612): 11-01 03:55:04.622: E/AndroidRuntime(1612): 11-01 03:55:04.622: E/AndroidRuntime(1612): 11-01 03:55:04.622: E/AndroidRuntime(1612): 11-01 03:55:04.622: E/AndroidRuntime(1612): 11-01 03:55:04.622: E/AndroidRuntime(1612): 11-01 03:55:04.622: E/AndroidRuntime(1612): 11-01 03:55:04.622: E/AndroidRuntime(1612): 11-01 03:55:04.622: E/AndroidRuntime(1612): 11-01 03:55:04.622: E/AndroidRuntime(1612): 11-01 03:55:04.622: E/AndroidRuntime(1612): 11-01 03:55:04.622: E/AndroidRuntime(1612): 11-01 03:55:04.622: E/AndroidRuntime(1612): 11-01 03:55:04.622: E/AndroidRuntime(1612): 11-01 03:55:04.622: E/AndroidRuntime(1612): 11-01 03:55:04.622: E/AndroidRuntime(1612): 11-01 03:55:04.622: E/AndroidRuntime(1612): 11-01 03:55:04.622: E/AndroidRuntime(1612): 11-01 03:55:04.622: E/AndroidRuntime(1612): 11-01 03:55:04.622: E/AndroidRuntime(1612): 11-01 03:55:04.622: E/AndroidRuntime(1612): 11-01 03:55:04.622: E/AndroidRuntime(1612): 11-01 03:55:04.622: E/AndroidRuntime(1612): 11-01 03:55:04.622: E/AndroidRuntime(1612): 11-01 03:55:04.622: E/AndroidRuntime(1612): 11-01 03:55:04.622: E/AndroidRuntime(1612): 11-01 03:55:04.622: E/AndroidRuntime(1612): 11-01 03:55:04.622: E/AndroidRuntime(1612): 11-01 03:55:04.622: E/AndroidRuntime(1612): 11-01 03:55:04.622: E/AndroidRuntime(1612): 11-01 03:55:09.212: I/Process(1612): FATAL EXCEPTION: main java.lang.IllegalStateException: Could not execute method of the activity at android.view.View$1.onClick(View.java:3633) at android.view.View.performClick(View.java:4240) at android.view.View$PerformClick.run(View.java:17721) at android.os.Handler.handleCallback(Handler.java:730) at android.os.Handler.dispatchMessage(Handler.java:92) at android.os.Looper.loop(Looper.java:137) at android.app.ActivityThread.main(ActivityThread.java:5103) at java.lang.reflect.Method.invokeNative(Native Method) at java.lang.reflect.Method.invoke(Method.java:525) at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:737) at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:553) at dalvik.system.NativeStart.main(Native Method) Caused by: java.lang.reflect.InvocationTargetException at java.lang.reflect.Method.invokeNative(Native Method) at java.lang.reflect.Method.invoke(Method.java:525) at android.view.View$1.onClick(View.java:3628) ... 11 more Caused by: android.os.NetworkOnMainThreadException at android.os.StrictMode$AndroidBlockGuardPolicy.onNetwork(StrictMode.java:1133) 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) at com.example.door.MainActivity.open(MainActivity.java:51) ... 14 more Sending signal. PID: 1612 SIG: 9

Thanks in advance Jeff

score 1 · Accepted Answer

您正在尝试从 Android SDK 不允许的应用程序的 UI 线程启动网络连接。

您可以继承 Android SDK 中提供的 AsyncTask 类，以将网络调用分离到单独的线程。

这是链接 http://developer.android.com/reference/android/os/AsyncTask.html

希望能帮助到你。

score 0 · Accepted Answer

尝试在你的onCreate()方法中添加这个

StrictMode.ThreadPolicy policy = new StrictMode.ThreadPolicy.Builder()
                .permitAll().build();
        StrictMode.setThreadPolicy(policy);

score 0 · Accepted Answer

您需要将请求的方法移动到后台线程中。我推荐使用 AsyncTask。你可以这样做：

import java.io.IOException;
import java.io.UnsupportedEncodingException;
import java.util.ArrayList;
import java.util.List;
import org.apache.http.NameValuePair;
import org.apache.http.client.ClientProtocolException;
import org.apache.http.client.HttpClient;
import org.apache.http.client.entity.UrlEncodedFormEntity;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.impl.client.DefaultHttpClient;
import org.apache.http.message.BasicNameValuePair;

import android.os.AsyncTask;
import android.os.Bundle;
import android.app.Activity;
import android.util.Log;
import android.view.Menu;
import android.view.View;
import android.widget.Button;

public class MainActivity extends Activity {
    Button opendoor;
    Button closedoor;

    private static final int CLOSE_METHOD = 1;
    private static final int OPEN_METHOD = 2;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        // Make Object for Buttons
        // sendButton = (Button) findViewById(R.id.sendButton);
        Button openbutton = (Button) findViewById(R.id.openButton);
        Button closebutton = (Button) findViewById(R.id.closeButton);

    }

    // When the send button is clicked
    public void open(View v) {
        BackgroundTask openTask = new BackgroundTask();
        openTask.execute(OPEN_METHOD);
        return;
    }

    public void close(View v) {
        BackgroundTask closeTask = new BackgroundTask();
        closeTask.execute(CLOSE_METHOD);
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.main, menu);
        return true;
    }

    class BackgroundTask extends AsyncTask<Integer, Void, String> {

        @Override
        protected String doInBackground(Integer... params) {
            switch (params[0]) {
            case CLOSE_METHOD:
                HttpClient httpclient = new DefaultHttpClient();
                HttpPost httppost = new HttpPost(
                        "http://devel.foo.bar/04r0450240");
                try {
                    List<NameValuePair> nameValuePairs = new ArrayList<NameValuePair>(
                            1);
                    nameValuePairs.add(new BasicNameValuePair("led", "0"));
                    httppost.setEntity(new UrlEncodedFormEntity(nameValuePairs));
                    httpclient.execute(httppost);
                } catch (ClientProtocolException e) {
                    e.printStackTrace();
                } catch (IOException e) {
                    e.printStackTrace();
                }
                break;
            case OPEN_METHOD:
                String server = "http://devel.foo.bar/04r0450240";
                HttpClient httpclient = new DefaultHttpClient();
                HttpPost httppost = new HttpPost(server);
                try {
                    List<NameValuePair> nameValuePairs = new ArrayList<NameValuePair>(
                            1);
                    nameValuePairs.add(new BasicNameValuePair("led", "1"));
                    httppost.setEntity(new UrlEncodedFormEntity(nameValuePairs));

                    try {
                        httpclient.execute(httppost);
                    } catch (UnsupportedEncodingException e) {
                        e.printStackTrace();
                    }
                } catch (IOException e) {
                    // TODO Auto-generated catch block
                    Log.i("HTTP Failed", e.toString());
                }
                break;
            }
            return null;
        }

        @Override
        protected void onPostExecute(String result) {
            // Here you can do something after the Asynctask has finished.
            super.onPostExecute(result);
        }

    }

}

这个想法是 Android 不允许您在主线程上执行网络操作。AsyncTask 是您情况下的最佳解决方案...它还具有在 doInBackground 启动之前调用的 onPreExecute() 方法，在这里您可以对进程进行一些初始化，或者您可以显示加载窗口并在 onPostExecute() 中将其关闭方法。

希望这对您有所帮助。

android - Trying to send post to server but app keeps dying

3 回答 3

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