URL不正确，代码不执行

今天在做service小练习的时候，发现了一个问题，android有时候报错， 并不往控制台打，所以以后要养成Log的习惯。

其中URL一定要正确。否则会报Protocol not found :www.XXXXX.com

下面贴上代码，让大家一起学习。做的小练习是service后台模拟异步下载东西。

MainActivity.java

package com.example.services;

import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;

public class MainActivity extends Activity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        
    }
    public void start(View v){
        Intent intent = new Intent(this,MyService.class);
        startService(intent);
    }
    public void stop(View v){
        Intent intent = new Intent(this,MyService.class);
        stopService(intent);
    }
    public void down(View v){
        start(v);
    }
}

View Code

MyService.java

package com.example.services;

import java.net.MalformedURLException;
import java.net.URL;

import android.app.Service;
import android.content.Intent;
import android.os.AsyncTask;
import android.os.IBinder;
import android.util.Log;
import android.widget.Toast;

public class MyService extends Service {

    @Override
    public IBinder onBind(Intent intent) {
        return null;
    }
    @Override
    public int onStartCommand(Intent intent, int flags, int startId) {
        Toast.makeText(getBaseContext(), "onStartCommand", 1).show();;
         try {
            new DoBackgroundTask().execute(
                    new URL("www.12345.com"),
                    new URL("www.12345.com"),
                    new URL("www.12345.com"),
                    new URL("www.12345.com"));
        } catch (MalformedURLException e) {
            Log.i("app", e.getMessage());
            e.printStackTrace();
        }
        return super.onStartCommand(intent, flags, startId);
    }
    @Override
    public void onDestroy() {
        super.onDestroy();
        Toast.makeText(this, "onDestroy", 1).show();
    }
    private int downloadFile(URL url){
        try {
            Thread.sleep(5000);
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
        return 100;
    }
//    private class DoBackgroundTask extends AsyncTask{
//
//        @Override
//        protected Long doInBackground(URL... params) {
//            Log.i("app", "doInBackground");
//            int count = params.length;
//            long totalBytesDownload = 0;
//            for (int i = 0; i < count; i++) {
//                Log.i("app", "i="+i);
//                totalBytesDownload += downloadFile(params[i]);
//                publishProgress(((i+1)/count)*100);
//            }
//            return totalBytesDownload;
//        }
//        @Override
//        protected void onProgressUpdate(Integer... values) {
//            Log.i("app", "onProgressUpdate");
//            Toast.makeText(getBaseContext(),"下载"+values[0]+"%", 1).show();
//            super.onProgressUpdate(values);
//        }
//        @Override
//        protected void onPostExecute(Long result) {
//            Toast.makeText(getBaseContext(),"下载"+result+"kb", 1).show();
//            super.onPostExecute(result);
//        }
//    }
    private class DoBackgroundTask extends AsyncTask {
        protected Long doInBackground(URL... urls) {
            int count = urls.length;
            long totalBytesDownloaded = 0;
            for (int i = 0; i < count; i++) {
                totalBytesDownloaded += downloadFile(urls[i]);
                //---calculate percentage downloaded and
                // report its progress---
                publishProgress((int) (((i+1) / (float) count) * 100));
            }
            return totalBytesDownloaded;
        }

        protected void onProgressUpdate(Integer... progress) {
            Log.d("Downloading files",
                    String.valueOf(progress[0]) + "% downloaded");
            Toast.makeText(getBaseContext(),
                String.valueOf(progress[0]) + "% downloaded",
                Toast.LENGTH_LONG).show();
        }

        protected void onPostExecute(Long result) {
            Toast.makeText(getBaseContext(),
                    "Downloaded " + result + " bytes",
                    Toast.LENGTH_LONG).show();
            stopSelf();
        }
    }
}

View Code

AndroidManifest.xml

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

    <uses-sdk
        android:minSdkVersion="8"
        android:targetSdkVersion="21" />

    <application
        android:allowBackup="true"
        android:icon="@drawable/ic_launcher"
        android:label="@string/app_name"
        android:theme="@style/AppTheme" >
        <activity
            android:name=".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>
        <service
            android:name=".MyService" 
            >service>
    application>

manifest>

View Code

 

转载于:https://www.cnblogs.com/mrgong/p/3983260.html