android 自动更新APP版本，并使用ProgressDialog显示进度

一、主要应用异步消息处理机制，在子线程进行版本检测和版本对比，如有新版本则开启新的线程去下载，并在progressDialog上显示下载进度，最后自动安装，这就是大概的实现思路。主要用到的知识就是网络请求和异步消息处理，以及文件读写。

二、代码如下

1、主活动

private UpdateAppManager manager;protected void onCreate(Bundle savedInstanceState) {   super.onCreate(savedInstanceState);   requestWindowFeature(Window.FEATURE_NO_TITLE);   setContentView(R.layout.guide);   manager=new UpdateAppManager(this);   manager.getUpdateMsg();//检查更新

2、更新管理类

public class UpdateAppManager {    // 外存sdcard存放路径    private static final String FILE_PATH = Environment.getExternalStorageDirectory() +"/" + "AutoUpdate" +"/";    // 下载应用存放全路径    private static final String FILE_NAME = FILE_PATH + "AutoUpdate.apk";    // 准备安装新版本应用标记    private static final int INSTALL_TOKEN = 1;    //Log日志打印标签    private static final String TAG = "Update_log";    private Context context;    //获取版本数据的地址    private String version_path = "http://10.3.3.239/get_data.json";    //获取新版APK的默认地址    private String apk_path = "http://10.3.3.239/PLAYBULBX.apk";    // 下载应用的进度条    private ProgressDialog progressDialog;    //新版本号和描述语言    private int update_versionCode;    private String update_describe;    public UpdateAppManager(Context context) {        this.context = context;    }    /**     * 获取当前版本号     */    private int getCurrentVersion() {        try {            PackageManager manager = context.getPackageManager();            PackageInfo info = manager.getPackageInfo(context.getPackageName(), 0);            Log.e(TAG, "当前版本名和版本号" + info.versionName + "--" + info.versionCode);            return info.versionCode;        } catch (Exception e) {            e.printStackTrace();            Log.e(TAG, "获取当前版本号出错");            return 0;        }    }    /**     * 从服务器获得更新信息     */    public void getUpdateMsg() {        class mAsyncTask extends AsyncTask<String, Integer, String> {            @Override            protected String doInBackground(String... params) {                HttpURLConnection connection = null;                try {                    URL url_version = new URL(params[0]);                    connection = (HttpURLConnection) url_version.openConnection();                    connection.setConnectTimeout(8000);                    connection.setReadTimeout(8000);                    InputStream in = connection.getInputStream();                    BufferedReader reader = new BufferedReader(new InputStreamReader(in, "GBK"));                    Log.e(TAG, "bufferReader读到的数据--" + reader);                    StringBuilder response = new StringBuilder();                    String line;                    while ((line = reader.readLine()) != null) {                        response.append(line);                    }                    return response.toString();                } catch (Exception e) {                    e.printStackTrace();                } finally {                    if (connection != null) {                        connection.disconnect();                    }                }                return null;            }            @Override            protected void onPostExecute(String s) {             //回到主线程，更新UI                Log.e(TAG, "异步消息处理反馈--" + s);                try {                    JSONObject object = new JSONObject(s);                    update_versionCode = object.getInt("version");                    update_describe = object.getString("describe");                    Log.e(TAG, "新版本号--" + update_versionCode);                    Log.e(TAG, "新版本描述--\n" + update_describe);                } catch (JSONException e) {                    e.printStackTrace();                }                if (update_versionCode > getCurrentVersion()) {                    Log.e(TAG, "提示更新！");                    showNoticeDialog();                } else {                    Log.e(TAG, "已是最新版本！");                }            }        }        new mAsyncTask().execute(version_path);    }    /**     * 显示提示更新对话框     */    private void showNoticeDialog() {        new AlertDialog.Builder(context)                .setTitle("检测到新版本！")                .setMessage(update_describe)                .setPositiveButton("下载", new DialogInterface.OnClickListener() {                    @Override                    public void onClick(DialogInterface dialog, int which) {                        dialog.dismiss();                        showDownloadDialog();                    }                }).setNegativeButton("下次再说", new DialogInterface.OnClickListener() {            @Override            public void onClick(DialogInterface dialog, int which) {                dialog.dismiss();            }        }).create().show();    }    /**     * 显示下载进度对话框     */    public void showDownloadDialog() {        progressDialog = new ProgressDialog(context);        progressDialog.setTitle("正在下载...");        progressDialog.setCanceledOnTouchOutside(true);        progressDialog.setProgressStyle(ProgressDialog.STYLE_HORIZONTAL);        new downloadAsyncTask().execute();    }    /**     * 下载新版本应用     */    private class downloadAsyncTask extends AsyncTask<Void, Integer, Integer> {        @Override        protected void onPreExecute() {            Log.e(TAG, "执行至--onPreExecute");            progressDialog.show();        }        @Override        protected Integer doInBackground(Void... params) {            Log.e(TAG, "执行至--doInBackground");            URL url;            HttpURLConnection connection = null;            InputStream in = null;            FileOutputStream out = null;            try {                url = new URL(apk_path);                connection = (HttpURLConnection) url.openConnection();                in = connection.getInputStream();                long fileLength = connection.getContentLength();                File file_path = new File(FILE_PATH);                if (!file_path.exists()) {                    file_path.mkdir();                }                out = new FileOutputStream(new File(FILE_NAME));//为指定的文件路径创建文件输出流                byte[] buffer = new byte[1024 * 1024];                int len = 0;                long readLength = 0;                Log.e(TAG, "执行至--readLength = 0");                while ((len = in.read(buffer)) != -1) {                    out.write(buffer, 0, len);//从buffer的第0位开始读取len长度的字节到输出流                    readLength += len;                    int curProgress = (int) (((float) readLength / fileLength) * 100);                    Log.e(TAG, "当前下载进度：" + curProgress);                    publishProgress(curProgress);                    if (readLength >= fileLength) {                        Log.e(TAG, "执行至--readLength >= fileLength");                        break;                    }                }                out.flush();                return INSTALL_TOKEN;            } catch (Exception e) {                e.printStackTrace();            } finally {                if (out != null) {                    try {                        out.close();                    } catch (IOException e) {                        e.printStackTrace();                    }                }                if (in != null) {                    try {                        in.close();                    } catch (IOException e) {                        e.printStackTrace();                    }                }                if (connection != null) {                    connection.disconnect();                }            }            return null;        }        @Override        protected void onProgressUpdate(Integer... values) {            Log.e(TAG, "异步更新进度接收到的值：" + values[0]);            progressDialog.setProgress(values[0]);        }        @Override        protected void onPostExecute(Integer integer) {            progressDialog.dismiss();//关闭进度条            //安装应用            installApp();        }    }    /**     * 安装新版本应用     */    private void installApp() {        File appFile = new File(FILE_NAME);        if (!appFile.exists()) {            return;        }        // 跳转到新版本应用安装页面        Intent intent = new Intent(Intent.ACTION_VIEW);        intent.setDataAndType(Uri.parse("file://" + appFile.toString()), "application/vnd.android.package-archive");        context.startActivity(intent);    }}

3、别忘了添加权限

<uses-permission android:name="android.permission.INTERNET"/><uses-permission android:name="android.permission.MOUNT_UNMOUNT_FILESYSTEMS"/><uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>

学习android 大概半年，菜鸟级别，第一次写博客，自己总结下经验，也抛砖引玉，望高人指点，不知道有没人会看呢？