android开发

安卓应用检查更新并下载安装

在这篇文章中（参见 android中如何下载文件并显示下载进度  ）我们讲到了如何下载文件的问题，今天我介绍如何实现应用的自动更新，其中下载apk模块用到了前一篇文章中的知识。当然这只是一个实现的框架，你需要根据自己的需求是改变一些细节。

自动更新的原理

其实就是客户端将自己的版本号与服务端的版本号进行比对，版本号小于服务端则意味着有新版本，当然服务端的版本号是需要人工放上去的。

先看看效果：

为了代码的简洁，我这里用原生的alert对话框。

点击下载之后：

下载完成安装的界面我就不张贴了。

使用方法：

很简单，在需要检查更新的地方加入如下代码:

updateChecker.setCheckUrl("http://jcodecraeer.com/update.php");
updateChecker.checkForUpdates();

其中http://jcodecraeer.com/update.php返回的是服务器段存放的版本信息。服务端的版本信息分为三部分：

1.版本号；

2.版本描述；

3.存放apk的url（告诉客户端，在哪里下载新版本的apk）；

以http://jcodecraeer.com/update.php返回的结果为例,返回的字符串具体是这样的：

{"url":"http://www.jcodecraeer.com/***.apk","versionCode":"2","updateMessage":"1.修改了app图标 2.设备详情的显示方式"}

这是一个json格式的字符串。

实现

有三个类：

其中

AppVersion是版本信息的模型类，基本上和服务端返回的东西是相对应的。

DownloadService是下载模块。

UpdateChecker是检查更新，调用下载模块，下载完安装的工具类。

AppVersion

package com.jcodecraeer.jcode.update;
public class AppVersion {
    private String updateMessage;
    private String apkUrl;
    private int apkCode;
    public static final String APK_DOWNLOAD_URL = "url";
    public static final String APK_UPDATE_CONTENT = "updateMessage";
    public static final String APK_VERSION_CODE = "versionCode";
    public void setUpdateMessage(String updateMessage) {
        this.updateMessage = updateMessage;
    }
    public String getUpdateMessage() {
        return updateMessage;
    }
    public void setApkUrl(String apkUrl) {
        this.apkUrl = apkUrl;
    }
    public String getApkUrl() {
        return apkUrl;
    }
    public void setApkCode(int apkCode) {
        this.apkCode = apkCode;
    }
    public int getApkCode() {
        return apkCode;
    }
}

DownloadService

package com.jcodecraeer.jcode.update;
import java.io.BufferedInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.net.URL;
import java.net.URLConnection;
import java.util.ArrayList;
import java.util.Date;
import java.util.HashMap;
import java.util.Map;
import org.jsoup.Jsoup;
import org.jsoup.nodes.Document;
import org.jsoup.nodes.Element;
import org.jsoup.select.Elements;
import com.jcodecraeer.PullToRefreshListView;
import android.annotation.SuppressLint;
import android.app.AlertDialog;
import android.app.IntentService;
import android.content.ContentResolver;
import android.content.ContentUris;
import android.content.Context;
import android.content.DialogInterface;
import android.content.Intent;
import android.content.res.TypedArray;
import android.database.Cursor;
import android.graphics.Rect;
import android.graphics.drawable.ColorDrawable;
import android.net.Uri;
import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
import android.os.ResultReceiver;
import android.provider.ContactsContract;
import android.provider.MediaStore.Images;
import android.provider.MediaStore.Images.ImageColumns;
import android.support.v4.app.Fragment;
import android.util.DisplayMetrics;
import android.util.Log;
import android.util.SparseBooleanArray;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.MenuInflater;
import android.view.MenuItem;
import android.view.View;
import android.view.ViewGroup;
import android.view.ViewGroup.LayoutParams;
import android.widget.AbsListView;
import android.widget.AdapterView;
import android.widget.AdapterView.OnItemClickListener;
import android.widget.GridView;
import android.widget.ShareActionProvider;
import android.widget.TextView;
import android.widget.Toast;
import android.view.ActionMode;
public class DownloadService extends IntentService {
    public static final int UPDATE_PROGRESS = 8344;
    public DownloadService() {
        super("DownloadService");
    }
    @Override
    protected void onHandleIntent(Intent intent) {
        String urlToDownload = intent.getStringExtra("url");
        String fileDestination = intent.getStringExtra("dest");
        ResultReceiver receiver = (ResultReceiver) intent.getParcelableExtra("receiver");
        try {
            URL url = new URL(urlToDownload);
            URLConnection connection = url.openConnection();
            connection.connect();
            // this will be useful so that you can show a typical 0-100% progress bar
            int fileLength = connection.getContentLength();
            // download the file
            InputStream input = new BufferedInputStream(connection.getInputStream());
            OutputStream output = new FileOutputStream(fileDestination);
            byte data\[\] = new byte\[100\];
            long total = 0;
            int count;
            while ((count = input.read(data)) != -1) {
                total += count;
                // publishing the progress....
                Bundle resultData = new Bundle();
                resultData.putInt("progress" ,(int) (total * 100 / fileLength));
                receiver.send(UPDATE_PROGRESS, resultData);
                output.write(data, 0, count);
            }
            output.flush();
            output.close();
            input.close();
        } catch (IOException e) {
            e.printStackTrace();
        }
        Bundle resultData = new Bundle();
        resultData.putInt("progress" ,100);
        receiver.send(UPDATE_PROGRESS, resultData);
    }
}

UpdateChecker

package com.jcodecraeer.jcode.update;
import java.io.BufferedReader;
import java.io.File;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.URL;
import java.util.ArrayList;
import java.util.Date;
import java.util.zip.GZIPInputStream;
import org.json.JSONException;
import org.json.JSONObject;
import com.jcodecraeer.jcode.Code;
import android.app.AlertDialog;
import android.app.ProgressDialog;
import android.content.Context;
import android.content.DialogInterface;
import android.content.Intent;
import android.content.pm.PackageManager;
import android.net.Uri;
import android.os.Bundle;
import android.os.Environment;
import android.os.Handler;
import android.os.Message;
import android.os.ResultReceiver;
import android.util.Log;
import android.widget.Toast;
public class UpdateChecker{
    private static final String TAG = "UpdateChecker";
    private Context mContext;
    //检查版本信息的线程
    private Thread mThread;
    //版本对比地址
    private String mCheckUrl;
    private AppVersion mAppVersion;
    //下载apk的对话框
    private ProgressDialog mProgressDialog;
    private File apkFile;
    public void setCheckUrl(String url) {
        mCheckUrl = url;
    }
    public UpdateChecker(Context context) {
        mContext = context;
        // instantiate it within the onCreate method
        mProgressDialog = new ProgressDialog(context);
        mProgressDialog.setMessage("正在下载");
        mProgressDialog.setIndeterminate(false);
        mProgressDialog.setProgressStyle(ProgressDialog.STYLE_HORIZONTAL);
        mProgressDialog.setCancelable(true);
        mProgressDialog.setOnCancelListener(new DialogInterface.OnCancelListener() {
            @Override
            public void onCancel(DialogInterface dialog) {
            }
        });
        mProgressDialog.setOnDismissListener(new DialogInterface.OnDismissListener() {
            @Override
            public void onDismiss(DialogInterface dialog) {
                // TODO Auto-generated method stub
            }
        });
    }
    public void checkForUpdates() {
        if(mCheckUrl == null) {
            //throw new Exception("checkUrl can not be null");
            return;
        }
        final  Handler handler = new Handler(){
            public void handleMessage(Message msg) {     
                if (msg.what == 1) {
                    mAppVersion = (AppVersion) msg.obj;
                    try{
                        int versionCode = mContext.getPackageManager().getPackageInfo(mContext.getPackageName(), 0).versionCode;
                        if (mAppVersion.getApkCode() > versionCode) {
                                showUpdateDialog();
                        } else {
                            //Toast.makeText(mContext, "已经是最新版本", Toast.LENGTH_SHORT).show();
                        }
                    }catch (PackageManager.NameNotFoundException ignored) {
                        //
                    }
                }
            }
        };
        mThread = new Thread() {
            @Override
            public void run() {
                //if (isNetworkAvailable(mContext)) {
                Message msg = new Message();
                String json = sendPost();
                Log.i("jianghejie","json = "+json);
                if(json!=null){
                    AppVersion appVersion = parseJson(json);
                    msg.what = 1;
                    msg.obj = appVersion;
                    handler.sendMessage(msg);
                }else{
                    Log.e(TAG, "can't get app update json");
                }
            }
        };
        mThread.start();
    }
    protected String sendPost() {
        HttpURLConnection uRLConnection = null;
        InputStream is = null;
        BufferedReader buffer = null;
        String result = null;
        try {
            URL url = new URL(mCheckUrl);
            uRLConnection = (HttpURLConnection) url.openConnection();
            uRLConnection.setDoInput(true);
            uRLConnection.setDoOutput(true);
            uRLConnection.setRequestMethod("POST");
            uRLConnection.setUseCaches(false);
            uRLConnection.setConnectTimeout(10 * 1000);
            uRLConnection.setReadTimeout(10 * 1000);
            uRLConnection.setInstanceFollowRedirects(false);
            uRLConnection.setRequestProperty("Connection", "Keep-Alive");
            uRLConnection.setRequestProperty("Charset", "UTF-8");
            uRLConnection.setRequestProperty("Accept-Encoding", "gzip, deflate");
            uRLConnection.setRequestProperty("Content-Type", "application/json");
            uRLConnection.connect();
            is = uRLConnection.getInputStream();
            String content_encode = uRLConnection.getContentEncoding();
            if (null != content_encode && !"".equals(content_encode) && content_encode.equals("gzip")) {
                is = new GZIPInputStream(is);
            }
            buffer = new BufferedReader(new InputStreamReader(is));
            StringBuilder strBuilder = new StringBuilder();
            String line;
            while ((line = buffer.readLine()) != null) {
                strBuilder.append(line);
            }
            result = strBuilder.toString();
        } catch (Exception e) {
            Log.e(TAG, "http post error", e);
        } finally {
            if(buffer!=null){
                try {
                    buffer.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
            if(is!=null){
                try {
                    is.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
            if(uRLConnection!=null){
                uRLConnection.disconnect();
            }
        }
        return result;
    }
    private AppVersion parseJson(String json) {
        AppVersion appVersion = new AppVersion();
        try {
            JSONObject obj = new JSONObject(json);
            String updateMessage = obj.getString(AppVersion.APK_UPDATE_CONTENT);
            String apkUrl = obj.getString(AppVersion.APK_DOWNLOAD_URL);
            int apkCode = obj.getInt(AppVersion.APK_VERSION_CODE);
            appVersion.setApkCode(apkCode);
            appVersion.setApkUrl(apkUrl);
            appVersion.setUpdateMessage(updateMessage);
        } catch (JSONException e) {
            Log.e(TAG, "parse json error", e);
        }
        return appVersion;
    }
    public void showUpdateDialog() {
        AlertDialog.Builder builder = new AlertDialog.Builder(mContext);
        //builder.setIcon(R.drawable.icon);
        builder.setTitle("有新版本");
        builder.setMessage(mAppVersion.getUpdateMessage());
        builder.setPositiveButton("下载",
            new DialogInterface.OnClickListener() {
                public void onClick(DialogInterface dialog, int whichButton) {
                    downLoadApk();
                }
        });
        builder.setNegativeButton("忽略",
            new DialogInterface.OnClickListener() {
                public void onClick(DialogInterface dialog, int whichButton) {
                }
        });
        builder.show();      
    }
    public void downLoadApk() {
        String apkUrl = mAppVersion.getApkUrl();
        String dir = mContext.getExternalFilesDir( "apk").getAbsolutePath();
        File folder = Environment.getExternalStoragePublicDirectory(dir);
        if(folder.exists() && folder.isDirectory()) {
             //do nothing
        }else {
            folder.mkdirs();
        }
        String filename = apkUrl.substring(apkUrl.lastIndexOf("/"),apkUrl.length());
        String destinationFilePath =  dir + "/" + filename;
        apkFile = new File(destinationFilePath);
        mProgressDialog.show();
        Intent intent = new Intent(mContext, DownloadService.class);
        intent.putExtra("url", apkUrl);
        intent.putExtra("dest", destinationFilePath);
        intent.putExtra("receiver", new DownloadReceiver(new Handler()));
        mContext.startService(intent);
    }
    private class DownloadReceiver extends ResultReceiver{
        public DownloadReceiver(Handler handler) {
            super(handler);
        }
        @Override
        protected void onReceiveResult(int resultCode, Bundle resultData) {
            super.onReceiveResult(resultCode, resultData);
            if (resultCode == DownloadService.UPDATE_PROGRESS) {
                int progress = resultData.getInt("progress");
                mProgressDialog.setProgress(progress);
                if (progress == 100) {
                    mProgressDialog.dismiss();
                    //如果没有设置SDCard写权限，或者没有sdcard,apk文件保存在内存中，需要授予权限才能安装
                    String\[\] command = {"chmod","777",apkFile.toString()};
                    try{
                        ProcessBuilder builder = new ProcessBuilder(command);
                        builder.start();
                        Intent intent = new Intent(Intent.ACTION_VIEW);
                        intent.setDataAndType(Uri.fromFile(apkFile), "application/vnd.android.package-archive");
                        mContext.startActivity(intent);
                    }catch (Exception e){
                    }
                }
            }
        }
    }
}

所有代码都已经贴出来了。

这个代码是完全可以用的，但是有些细节问题需要改进。

泡在网上的日子
每天进步一点点
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