HttpConnection

联网权限

public class MainActivity extends Activity {

    private File apkFile;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
    }
    
    public void downloadAPK(View v) {
        //1). 主线程, 显示提示视图: ProgressDialog
        final ProgressDialog dialog = new ProgressDialog(this);
        dialog.setProgressStyle(ProgressDialog.STYLE_HORIZONTAL);
        dialog.show();
        
        //准备用于保存APK文件的File对象 : /storage/sdcard/Android/package_name/files/xxx.apk
        apkFile = new File(getExternalFilesDir(null), "update.apk");
        
        //2). 启动分线程, 请求下载APK文件, 下载过程中显示下载进度
        new Thread(new Runnable() {
            
            @Override
            public void run() {
                try {
                    //1. 得到连接对象
                    String path = "http://192.168.10.165:8080/Web_Server/L04_DataStorage.apk";
                    URL url = new URL(path);
                    HttpURLConnection connection = (HttpURLConnection) url.openConnection();
                    //2. 设置
                    //connection.setRequestMethod("GET");
                    connection.setConnectTimeout(5000);
                    connection.setReadTimeout(10000);
                    //3. 连接
                    connection.connect();
                    //4. 请求并得到响应码200
                    int responseCode = connection.getResponseCode();
                    if(responseCode==200) {
                        //设置dialog的最大进度
                        dialog.setMax(connection.getContentLength());
                        
                        
                        //5. 得到包含APK文件数据的InputStream
                        InputStream is = connection.getInputStream();
                        //6. 创建指向apkFile的FileOutputStream
                        FileOutputStream fos = new FileOutputStream(apkFile);
                        //7. 边读边写
                        byte[] buffer = new byte[1024];
                        int len = -1;
                        while((len=is.read(buffer))!=-1) {
                            fos.write(buffer, 0, len);
                            //8. 显示下载进度
                            dialog.incrementProgressBy(len);
                            
                            //休息一会(模拟网速慢)
                            //Thread.sleep(50);
                            SystemClock.sleep(50);
                        }
                        
                        fos.close();
                        is.close();
                    }
                    //9. 下载完成, 关闭, 进入3)
                    connection.disconnect();
                    
                    //3). 主线程, 移除dialog, 启动安装
                    runOnUiThread(new Runnable() {
                        @Override
                        public void run() {
                            dialog.dismiss();
                            installAPK();
                        }
                    });
                    
                } catch (Exception e) {
                    e.printStackTrace();
                }
            }
        }).start();
        //09-05 12:59:20.553: I/ActivityManager(1179): Displayed com.android.packageinstaller/.PackageInstallerActivity: +282ms
    }