Question

我想通过POST方法发送字符串，但是出现此错误而我找不到，你能帮助我吗？

这给出了一个非常奇怪的异常，APA没有打开，现在出现错误，MainActivity屏幕不会出现。

我的代码：

MainActivity.java

package com.app.androidpost;

import java.io.IOException;
import java.util.ArrayList;
import java.util.List;

import org.apache.http.HttpResponse;
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 org.apache.http.util.EntityUtils;

import android.app.Activity;
import android.os.Bundle;
import android.view.Menu;
import android.widget.Toast;

public class MainActivity extends Activity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {

    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    HttpClient httpclient = new DefaultHttpClient(); 

        HttpPost httppost = new HttpPost("http://www.meusite.com/ws/default.php"); 

        try {

            List<NameValuePair> nameValuePairs = new ArrayList<NameValuePair>(2); 
            nameValuePairs.add(new BasicNameValuePair("action", "Sucesso")); 
            httppost.setEntity(new UrlEncodedFormEntity(nameValuePairs)); 

            HttpResponse response = httpclient.execute(httppost); 
            String responseText = EntityUtils.toString(response.getEntity()); 
            Toast.makeText(this, responseText , 5000).show(); 

        } 
        catch (ClientProtocolException e) { 
            Toast.makeText(this, "Erro Conversão" , 5000).show(); 
        } 
        catch (IOException e) {
            Toast.makeText(this, "Erro conexão" , 5000).show(); 
        } 

    }

}

的AndroidManifest.xml

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.app.androidpost"
    android:versionCode="1"
    android:versionName="1.0" >

    <uses-sdk
        android:minSdkVersion="15"
        android:targetSdkVersion="15" />
    <uses-permission android:name="android.permission.INTERNET"/>

    <application
        android:allowBackup="true"
        android:icon="@drawable/ic_launcher"
        android:label="@string/app_name"
        android:theme="@style/AppTheme" >
        <activity
            android:name="com.app.androidpost.MainActivity"
            android:label="@string/app_name" >
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
    </application>

</manifest>

PHP代码

<?php 

$reversed = $_POST["action"];

echo $reversed;

?>

logcat的

01-20 18:42:03.909: W/dalvikvm(25243): threadid=1: thread exiting with uncaught exception (group=0x40dab1f8)
01-20 18:42:03.949: E/AndroidRuntime(25243): FATAL EXCEPTION: main
01-20 18:42:03.949: E/AndroidRuntime(25243): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.app.androidpost/com.app.androidpost.MainActivity}: android.os.NetworkOnMainThreadException
01-20 18:42:03.949: E/AndroidRuntime(25243):    at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1960)
01-20 18:42:03.949: E/AndroidRuntime(25243):    at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1985)
01-20 18:42:03.949: E/AndroidRuntime(25243):    at android.app.ActivityThread.access$600(ActivityThread.java:127)
01-20 18:42:03.949: E/AndroidRuntime(25243):    at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1151)
01-20 18:42:03.949: E/AndroidRuntime(25243):    at android.os.Handler.dispatchMessage(Handler.java:99)
01-20 18:42:03.949: E/AndroidRuntime(25243):    at android.os.Looper.loop(Looper.java:137)
01-20 18:42:03.949: E/AndroidRuntime(25243):    at android.app.ActivityThread.main(ActivityThread.java:4476)
01-20 18:42:03.949: E/AndroidRuntime(25243):    at java.lang.reflect.Method.invokeNative(Native Method)
01-20 18:42:03.949: E/AndroidRuntime(25243):    at java.lang.reflect.Method.invoke(Method.java:511)
01-20 18:42:03.949: E/AndroidRuntime(25243):    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:816)
01-20 18:42:03.949: E/AndroidRuntime(25243):    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:583)
01-20 18:42:03.949: E/AndroidRuntime(25243):    at dalvik.system.NativeStart.main(Native Method)
01-20 18:42:03.949: E/AndroidRuntime(25243): Caused by: android.os.NetworkOnMainThreadException
01-20 18:42:03.949: E/AndroidRuntime(25243):    at android.os.StrictMode$AndroidBlockGuardPolicy.onNetwork(StrictMode.java:1099)
01-20 18:42:03.949: E/AndroidRuntime(25243):    at java.net.InetAddress.lookupHostByName(InetAddress.java:426)
01-20 18:42:03.949: E/AndroidRuntime(25243):    at java.net.InetAddress.getAllByNameImpl(InetAddress.java:277)
01-20 18:42:03.949: E/AndroidRuntime(25243):    at java.net.InetAddress.getAllByName(InetAddress.java:251)
01-20 18:42:03.949: E/AndroidRuntime(25243):    at org.apache.http.impl.conn.DefaultClientConnectionOperator.openConnection(DefaultClientConnectionOperator.java:137)
01-20 18:42:03.949: E/AndroidRuntime(25243):    at org.apache.http.impl.conn.AbstractPoolEntry.open(AbstractPoolEntry.java:164)
01-20 18:42:03.949: E/AndroidRuntime(25243):    at org.apache.http.impl.conn.AbstractPooledConnAdapter.open(AbstractPooledConnAdapter.java:119)
01-20 18:42:03.949: E/AndroidRuntime(25243):    at org.apache.http.impl.client.DefaultRequestDirector.execute(DefaultRequestDirector.java:360)
01-20 18:42:03.949: E/AndroidRuntime(25243):    at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:555)
01-20 18:42:03.949: E/AndroidRuntime(25243):    at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:487)
01-20 18:42:03.949: E/AndroidRuntime(25243):    at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:465)
01-20 18:42:03.949: E/AndroidRuntime(25243):    at com.app.androidpost.MainActivity.onCreate(MainActivity.java:38)
01-20 18:42:03.949: E/AndroidRuntime(25243):    at android.app.Activity.performCreate(Activity.java:4636)
01-20 18:42:03.949: E/AndroidRuntime(25243):    at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1051)
01-20 18:42:03.949: E/AndroidRuntime(25243):    at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1924)
01-20 18:42:03.949: E/AndroidRuntime(25243):    ... 11 more

非常感谢

Answer 1

您遇到错误，因为您尝试在主线程中连接到网络，这是不允许的正如您可以阅读here：

应用程序尝试执行时抛出的异常主线程上的网络操作。这仅适用于针对Honeycomb SDK或。的应用程序更高。允许使用早期SDK版本的应用程序他们的主要事件循环线程上的网络，但它是很重要的泄气。请参阅文档设计响应性。

你必须使用后台线程，例如AsyncTask。你有一个简单的guide here

您的代码将是这样的：

public class MainActivity extends Activity {

@Override
protected void onCreate(Bundle savedInstanceState) {

super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);

 new HttpTask().execute("http://www.meusite.com/ws/default.php");

}

private class HttpTask extends AsyncTask<String, Integer, Long> {

    protected Long doInBackground(String... urls) {
        int count = urls.length;
        long totalSize = 0;
        for (int i = 0; i < count; i++) {

            HttpClient httpclient = new DefaultHttpClient(); 

            HttpPost httppost = new HttpPost(urls[i]); 

             try {

              List<NameValuePair> nameValuePairs = new ArrayList<NameValuePair>(2); 
             nameValuePairs.add(new BasicNameValuePair("action", "Sucesso")); 
               httppost.setEntity(new UrlEncodedFormEntity(nameValuePairs)); 

              HttpResponse response = httpclient.execute(httppost); 
               String responseText = EntityUtils.toString(response.getEntity()); 
               Toast.makeText(this, responseText , 5000).show(); 

           } 
           catch (ClientProtocolException e) { 
               Toast.makeText(this, "Erro Conversão" , 5000).show(); 
           } 
           catch (IOException e) {
               Toast.makeText(this, "Erro conexão" , 5000).show(); 
           } 


            // Escape early if cancel() is called
            if (isCancelled()) break;
        }
        return totalSize;
    }


    protected void onProgressUpdate(Integer... progress) {    }

    protected void onPostExecute(Long result) { }
}


}

发送到PHP文件的HttpPost中的奇怪错误

1 个答案: