Android连接服务器实例安卓开发连接服务器

转载

技术笔耕者 2023-08-31 13:03:23

文章标签 Android连接服务器实例 android ide 服务器 文章分类 Android 移动开发

对于简单的应用程序，很少会需要连接服务器，单机运行就行了。但是当你需要不断更新软件版本，或者你的APP需要用到大量的资源而直接打包进APK文件太大，这时你就需要连接到服务器去下载文件。下面这个项目就提供了如何连接服务器更新APK和如何下载资源的方法。

连接服务器更新APK

服务器上放置一个记录版本号的txt文件，比如version.txt。放置一个用于更新的APK，比如new.apk

final static String strurl = "http:///my/version.txt";
final static String strurl_apk = "http:///my/new.apk";

MainActivity的onCreate()方法中调用CheckUpdate()方法

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    requestWindowFeature(Window.FEATURE_NO_TITLE);
    setContentView(R.layout.main);

    ......
    CheckUpdate(); // 检查更新
}

连接服务器前当然要先判断网络连接，如果是要下载到SD卡的，还要判断是否有SD卡，判断的代码很简单就不贴上了。

// 检查更新
private void CheckUpdate(boolean isAuto) {
    // 判断版本号，然后下载   
    downloader = new HttpDownLoader();
    int serverVersion = 1;
    serverVersion = Integer.parseInt(FusionField.downloader.downLoadText(strurl));
    if(serverVersion > localVersion) {
        AlertDialog.Builder builder = new Builder(this); 
        builder.setTitle("软件升级")
                .setMessage("发现新版本，是否升级！")
                .setPositiveButton("升级",new DialogInterface.OnClickListener() { 
                    @Override
                    public void onClick(DialogInterface dialog, int which) { 
                        //开启更新服务UpdateService
                        //这里为了把update更好模块化，可以传一些updateService依赖的值
                        //如布局ID，资源ID，动态获取的标题,这里以app_name为例
                        Intent updateIntent =new Intent(MainActivity.this, UpdateService.class);
                        startService(updateIntent);
                    }
                })
                .setNegativeButton("取消", new android.content.DialogInterface.OnClickListener() { 
                    @Override
                    public void onClick(DialogInterface dialog, int which) { 
                        dialog.dismiss(); 
                    } 
                });
        builder.create().show(); 
    }
}

UpdateService.class执行后台下载和通知栏下载进度条的更新

public class UpdateService extends Service{

//文件存储
private File updateDir = null;
private File updateFile = null; 
public static String downloadDir = "/download/";

//通知栏
private NotificationManager updateNotificationManager = null;
private Notification updateNotification = null;

//通知栏跳转Intent
private Intent updateIntent = null;
private PendingIntent updatePendingIntent = null;

//下载状态
private final static int DOWNLOAD_COMPLETE = 0;
private final static int DOWNLOAD_FAIL = 1;

@Override  
public void onCreate() {  
    super.onCreate();  
} 

@Override
public int onStartCommand(Intent intent, int flags, int startId) {      
    //创建文件
          if(android.os.Environment.MEDIA_MOUNTED.equals(android.os.Environment.getExternalStorageState())){
        updateDir = new File(Environment.getExternalStorageDirectory(),downloadDir);
        updateFile = new File(updateDir.getPath(),strurl_apk_name);

    }

    this.updateNotificationManager = (NotificationManager)getSystemService(NOTIFICATION_SERVICE);
    this.updateNotification = new Notification();

    //设置下载过程中，点击通知栏，回到主界面
    updateIntent = new Intent(this, MainActivity.class);
    updatePendingIntent = PendingIntent.getActivity(this,0,updateIntent,0);

    //设置通知栏显示内容
    updateNotification.icon = android.R.drawable.stat_sys_download;
    updateNotification.tickerText = "开始下载";
    updateNotification.setLatestEventInfo(this,apk_title,"0%",updatePendingIntent);

    //发出通知
    updateNotificationManager.notify(0,updateNotification);

    //开启一个新的线程下载，如果使用Service同步下载，会导致ANR问题，Service本身也会阻塞
    new Thread(new updateRunnable()).start();//这个是下载的重点，是下载的过程

    return super.onStartCommand(intent, flags, startId);
}

private Handler updateHandler = new  Handler(){
    @Override
    public void handleMessage(Message msg) {
        switch(msg.what){
            case DOWNLOAD_COMPLETE:
                //点击安装PendingIntent
                Uri uri = Uri.fromFile(updateFile);
                Intent installIntent = new Intent(Intent.ACTION_VIEW);
                installIntent.setDataAndType(uri, "application/vnd.android.package-archive");
                updatePendingIntent = PendingIntent.getActivity(UpdateService.this, 0, installIntent, 0);

                updateNotification.defaults = Notification.DEFAULT_SOUND;//铃声提醒 
                updateNotification.setLatestEventInfo(UpdateService.this, FusionField.update_apk_title, "下载完成,点击安装。", updatePendingIntent);
                updateNotificationManager.notify(0, updateNotification);                    

                //停止服务
                stopSelf();
                break;
            case DOWNLOAD_FAIL:
                //下载失败
                updateNotification.setLatestEventInfo(UpdateService.this, FusionField.update_apk_title, "下载失败。", updatePendingIntent);
                updateNotificationManager.notify(0, updateNotification);
                break;
            default:
                stopSelf();
        }
    }
};

class updateRunnable implements Runnable {
    Message message = updateHandler.obtainMessage();
    public void run() {
        message.what = DOWNLOAD_COMPLETE;
        try{
            //增加权限;
            if(!updateDir.exists()){
                updateDir.mkdirs();
            }
            if(!updateFile.exists()){
                updateFile.createNewFile();
            }
            //下载函数
            //增加权限;
            String strurl = strurl_apk;
            long downloadSize = downloadUpdateFile(strurl,updateFile);
            if(downloadSize>0){
                //下载成功
                updateHandler.sendMessage(message);
            }
        }catch(Exception ex){
            ex.printStackTrace();
            message.what = DOWNLOAD_FAIL;
            //下载失败
            updateHandler.sendMessage(message);
        }
    }
}

public long downloadUpdateFile(String downloadUrl, File saveFile) throws Exception {
    int downloadCount = 0;
    int currentSize = 0;
    long totalSize = 0;
    int updateTotalSize = 0;

    HttpURLConnection httpConnection = null;
    InputStream is = null;
    FileOutputStream fos = null;

    try {
        URL url = new URL(downloadUrl);
        httpConnection = (HttpURLConnection)url.openConnection();
        httpConnection.setRequestProperty("User-Agent", "PacificHttpClient");
        if(currentSize > 0) {
            httpConnection.setRequestProperty("RANGE", "bytes=" + currentSize + "-");
        }
        httpConnection.setConnectTimeout(10000);
        httpConnection.setReadTimeout(20000);
        updateTotalSize = httpConnection.getContentLength();
        if (httpConnection.getResponseCode() == 404) {
            throw new Exception("fail!");
        }
        is = httpConnection.getInputStream();                   
        fos = new FileOutputStream(saveFile, false);
        byte buffer[] = new byte[4096];
        int readsize = 0;
        while((readsize = is.read(buffer)) > 0){
            fos.write(buffer, 0, readsize);
            totalSize += readsize;
            //为了防止频繁的通知导致应用吃紧，百分比增加10才通知一次，可自行调整
            if((downloadCount == 0)||(int) (totalSize*100/updateTotalSize)-10>downloadCount){ 
                downloadCount += 10;
                updateNotification.setLatestEventInfo(UpdateService.this, "正在下载", (int)totalSize*100/updateTotalSize+"%", updatePendingIntent);
                updateNotificationManager.notify(0, updateNotification);
            }                        
        }
    } finally {
        if(httpConnection != null) {
            httpConnection.disconnect();
        }
        if(is != null) {
            is.close();
        }
        if(fos != null) {
            fos.close();
        }
    }
    return totalSize;
}

@Override
public IBinder onBind(Intent arg0) {
    // TODO Auto-generated method stub
    return null;
}
}

下载资源文件

和下载APK文件相同的是，都使用HttpDownLoader()方法，不同的是，下载资源文件一般是需要弹出等待进度条阻塞用户操作的。

弹出等待框，开始下载

private ProgressDialog pd; //等待下载滚动圈

myRingtoneListView.setOnItemClickListener(new OnItemClickListener() {
            @Override   
            public void onItemClick(AdapterView<?> parent, View view, int position, long id) {

                currentSelected = position+1;

                // 下载更多
                if(position >= ringtoneNum) {

                    if(!isNetworkAvaiable()) {
                        Toast.makeText(RingtoneActivity.this, "请确认网络连接正常！", Toast.LENGTH_SHORT).show();
                        return;
                    }

                    if(!FusionField.sdState.equals(Environment.MEDIA_MOUNTED)) {
                        Toast.makeText(RingtoneActivity.this, "请插入SD卡！", Toast.LENGTH_SHORT).show();
                        return;
                    }

                    final int idToDownload = ringtoneNum+1;
                    FusionField.downloader = new HttpDownLoader();
                    pd = ProgressDialog.show(RingtoneActivity.this, "正在下载", "请等待。。。",true, true);
                    pd.setCanceledOnTouchOutside(false);
                    pd.setOnCancelListener(new ProgressDialog.OnCancelListener() {
                        @Override
                        public void onCancel(DialogInterface dialog) {
                            // 终止下载
                            pd.dismiss();
                        }
                    }); 
                    new Thread(){
                        public void run(){
                            //在这里执行长耗时方法

                            int res = downloader.downLoadFile(ringtone_path+"/ringtone"+ idToDownload + ".mp3", "download/ringtone", "/ringtone" + idToDownload + ".mp3");

                            //执行完毕后给handler发送一个消息                             
                            if(res == 0) {          
                                handler.sendEmptyMessage(0);
                                MainActivity main = MainActivity.getInstance();
                            }
                            else if(res == 1)
                                handler.sendEmptyMessage(1);
                            else
                                handler.sendEmptyMessage(3);    
                        }
                    }.start();
                    return;
                }

下载成功或失败的消息处理

//定义Handler对象
        private Handler handler =new Handler(){
            @Override
            //当有消息发送出来的时候就执行Handler的这个方法
            public void handleMessage(Message msg){
                switch(msg.what)
                {
                case 0: // 下载成功
                    Toast.makeText(RingtoneActivity.this, "下载完成！", Toast.LENGTH_SHORT).show();
                    finish();
                    break;
                case 1: // 文件已存在
                    Toast.makeText(RingtoneActivity.this, "文件已存在！" , Toast.LENGTH_LONG).show();
                    break;
                case 2: // 下载被取消
                    Toast.makeText(RingtoneActivity.this, "已终止下载！", Toast.LENGTH_SHORT).show();
                    break;
                case 3: // 下载出错
                    Toast.makeText(RingtoneActivity.this, "下载中断，请检查网络设置", Toast.LENGTH_SHORT).show();                               
                    break;
                case 4: // 服务器地址出错
                    Toast.makeText(RingtoneActivity.this, "服务器地址解析错误，请检查网络设置", Toast.LENGTH_SHORT).show();
                    break;
                }
                super.handleMessage(msg);
                //只要执行到这里就关闭对话框
                pd.dismiss();
             }
        };

本文章为转载内容，我们尊重原作者对文章享有的著作权。如有内容错误或侵权问题，欢迎原作者联系我们进行内容更正或删除文章。