Andoid应用更新，解决andrid5.0获取系统权限把下载APK存到SD卡中，版本号的比较，有手动更新和自动更新

最近项目刚做完1.2，1.2要上线1.0中写了应用更新代码，不过之前考虑不太全面，Android6.0不能直接跟新，原因把下载的APK要存储到SD卡中，需要获取存储权限。针对这个问题有两种解决方案，第一种是targetSdkVersion 22 就是targetSdkVersion小于23就行，但是之前版本写的23，上线之后在应用商店下载不能直接覆盖，得把之前卸载，感觉体验并不好；第一种是加上获取全下的代码。谢天谢地幸好之前没推广用户量并不多，要不然就该倒霉了，哎呦。话不多说，来干活

• 来先看效果

• UpdateData类主要从服务器获取更新的信息

public class UpdateData {
    /**
     * 版本号
     * */
    private String serverVersion;
    /**
     *下载地址
     * */
    private String apkUrl;
    /**
     * 版本号
     * */
    private String updateDescription;
    /**
     * 是否需要强制升级
     * */
    private boolean forceUpgrade;

    public String getServerVersion() {
        return serverVersion;
    }

    public void setServerVersion(String serverVersion) {
        this.serverVersion = serverVersion;
    }

    public String getApkUrl() {
        return apkUrl;
    }

    public void setApkUrl(String apkUrl) {
        this.apkUrl = apkUrl;
    }

    public String getUpdateDescription() {
        return updateDescription;
    }

    public void setUpdateDescription(String updateDescription) {
        this.updateDescription = updateDescription;
    }

    public boolean isForceUpgrade() {
        return forceUpgrade;
    }

    public void setForceUpgrade(boolean forceUpgrade) {
        this.forceUpgrade = forceUpgrade;
    }
}

• Activity

public class MainActivity extends Activity {
    private Button btn;
    private UpdateManager mUpdateManager;
    /**
     * 从服务器获取的版本号
     */
    private String serverVersion = "1.0.1";
    /**
     * 客户端当前的版本号
     */
    private String clientVersion = "1.0";
    UpdateData data;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        btn = (Button) findViewById(R.id.btn);
        data = new UpdateData();
        data.setServerVersion(serverVersion);
        data.setApkUrl("http://file.anruan.com/soft/6/chenggua_27951.apk");
        data.setUpdateDescription("更新说明：\n1.新增工作台模块\n2.新增门店选择\n3.新增顾问角色\n4.新增潜客功能\n5.新增合约功能\n6.新增统计功能问题");
        data.setForceUpgrade(false);
        checkUpdate(data);
        btn.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                checkUpdate(data);
            }
        });
    }
    public void checkUpdate(UpdateData updateBean) {
        if (updateBean != null) {
        }
        //比较版本号
        VersionComparator versionComparator = new VersionComparator();
        int flag = versionComparator.compare(clientVersion, serverVersion);
        if (flag != -1) {
        } else {
            mUpdateManager = new UpdateManager(
                    MainActivity.this,
                    updateBean
            );
        }
    }

}

• UpdateManager 里面有下载 获取权限的方法

public class UpdateManager {
    private Context mContext;
    /**
     * 下载地址
     */
    private String apkUrl;
    /**
     * apk保存到SD卡的路径
     */
    private static final String savePath = "/sdcard/GPF/";
    /**
     * 完整路径名
     */
    private static final String saveFileName = savePath + "gpf.apk";
    /**
     * 下载进度条控件
     */
    private ProgressBar mProgress;
    /**
     * 表示正在下载
     */
    private static final int DOWNLOADING = 1;
    /**
     * 下载完毕
     */
    private static final int DOWNLOADED = 2;
    /**
     * 下载失败
     */
    private static final int DOWNLOAD_FAILED = 3;
    /**
     * 下载进度
     */
    private int progress;
    /**
     * 取消下载标志位
     */
    private boolean cancelFlag = false;
    /**
     * 从服务器获取的版本号
     */
    private double serverVersion = 1.0;
    /**
     * 客户端当前的版本号
     */
    private double clientVersion = 1.0;
    /**
     * 更新内容描述信息
     */
    private String updateDescription = "";
    /**
     * 是否强制更新
     */
    private boolean forceUpdate = false;
    /**
     * 表示提示对话框、进度条对话框
     */
    private AlertDialog alertDialog1, alertDialog2;

    /**
     * 构造函数
     *
     * @param data
     */
    public UpdateManager(Context context, UpdateData data) {
        this.mContext = context;
        //查询当前版本号
//        clientVersion = getVersionName();
        //获取服务端新版本地址和版本号
        apkUrl = data.getApkUrl();
        if (data.getUpdateDescription() != null) {
            updateDescription = data.getUpdateDescription();
            forceUpdate = data.isForceUpgrade();
        }
        showNoticeDialog();
    }

    /**
     * 显示更新对话框
     */
    private  Dialog dialog;
    public void showNoticeDialog() {
        dialog = new Dialog(mContext, R.style.MyDialogStyle);
        final Window window = dialog.getWindow();
        window.setContentView(R.layout.alert_updata);
        TextView title = (TextView) window.findViewById(R.id.tv_msg);
        title.setText("更新");
        TextView titlec = (TextView) window.findViewById(R.id.tv_msgs);
        titlec.setText(updateDescription);
        window.findViewById(R.id.im_cancel).setOnClickListener(new View.OnClickListener() {

            @Override
            public void onClick(View v) {
                dialog.dismiss();
            }
        });
        TextView textView = (TextView) window.findViewById(R.id.im_cancel);
        if (forceUpdate) {
            textView.setVisibility(View.GONE);
        } else {
            textView.setVisibility(View.VISIBLE);
        }
        window.findViewById(R.id.im_confirm).setOnClickListener(new View.OnClickListener() {

            @Override
            public void onClick(View v) {
              checkPermissionsWRITE(new RxPermissions((Activity) mContext), new TaskReviewDetailContract.RxPermissionsListener() {
                    @Override
                    public void onSuccess() {
                        dialog.dismiss();
                        showDownloadDialog();
                    }

                    @Override
                    public void onFail() {

                    }
                });

            }
        });
        dialog.show();
    }

   public void checkPermissionsWRITE(RxPermissions rxPermissions, final TaskReviewDetailContract.RxPermissionsListener listener) {
        rxPermissions.request(Manifest.permission.WRITE_EXTERNAL_STORAGE)
                .subscribe(new Consumer() {
                    @Override
                    public void accept(@NonNull Boolean aBoolean) throws Exception {
                        if (aBoolean) {
                            listener.onSuccess();
                        } else {
                            listener.onFail();
                        }
                    }

                });
    }

    /**
     * 显示进度条对话框
     */
    public void showDownloadDialog() {
        final Dialog dialog = new Dialog(mContext, R.style.MyDialogStyle);
        final Window window = dialog.getWindow();
        window.setContentView(R.layout.alert_download);
        mProgress = (ProgressBar) window.findViewById(R.id.update_progress);
        //如果是强制更新，则不显示取消按钮
        window.findViewById(R.id.img_cancel).setOnClickListener(new View.OnClickListener() {

            @Override
            public void onClick(View v) {
                dialog.dismiss();
                cancelFlag = false;
            }
        });
        TextView textView = (TextView) window.findViewById(R.id.img_cancel);
        if (forceUpdate) {
            textView.setVisibility(View.GONE);
        } else {
            textView.setVisibility(View.VISIBLE);
        }
        dialog.show();
        //下载apk
        downloadAPK();
    }

    /**
     * 下载apk的线程
     */
    public void downloadAPK() {
        new Thread(new Runnable() {
            @Override
            public void run() {
        try {
            URL url = new URL(apkUrl);
            HttpURLConnection conn = (HttpURLConnection) url.openConnection();
            conn.connect();
            int length = conn.getContentLength();
            InputStream is = conn.getInputStream();
            File file = new File(savePath);
            if (!file.exists()) {
                file.mkdir();
            }
            String apkFile = saveFileName;
            File ApkFile = new File(apkFile);
            FileOutputStream fos = new FileOutputStream(ApkFile);
            //缓存流提高读取效率
            BufferedInputStream bis=new BufferedInputStream(is);
            BufferedOutputStream bos=new BufferedOutputStream(fos);
            int count = 0;
            byte buf[] = new byte[1024];
            //点击取消就停止下载.
            int numread=0;
            while ((numread =bis.read(buf))!=-1&&!cancelFlag){
                count += numread;
                progress = (int) (((float) count / length) * 100);
                //更新进度
                mHandler.sendEmptyMessage(DOWNLOADING);
                bos.write(buf, 0, numread);
                bos.flush();
            }
            /**
            *numread == -1说明信息已经读取完成 不知道的同学可以看看java IO
            */
            if (numread == -1) {
                //下载完成通知安装
                mHandler.sendEmptyMessage(DOWNLOADED);
            }
//          do {
//                int numread =is.read(buf);
//
//                count += numread;
//                progress = (int) (((float) count / length) * 100);
//                //更新进度
//                mHandler.sendEmptyMessage(DOWNLOADING);
//                if (numread == -1) {
//                    //下载完成通知安装
//                    mHandler.sendEmptyMessage(DOWNLOADED);
//                    break;
//                }
//               fos.write(buf, 0, numread);
//            } while (!cancelFlag);
            bos.close();
            bis.close();
        } catch (Exception e) {
            mHandler.sendEmptyMessage(DOWNLOAD_FAILED);
            e.printStackTrace();
        }
            }
        }).start();
    }


    /**
     * 更新UI的handler
     */
    private Handler mHandler = new Handler() {
        @Override
        public void handleMessage(Message msg) {
            switch (msg.what) {
                case DOWNLOADING:
                    mProgress.setProgress(progress);
                    break;
                case DOWNLOADED:
                    if (alertDialog2 != null) {
                        alertDialog2.dismiss();
                    }
                    installAPK();
                    break;
                case DOWNLOAD_FAILED:
                    Toast.makeText(mContext, "网络断开，请稍候再试", Toast.LENGTH_LONG).show();
                    break;
                default:
                    break;
            }
        }
    };

    /**
     * 下载完成后自动安装apk
     */
    public void installAPK() {
        File apkFile = new File(saveFileName);
        if (!apkFile.exists()) {
            return;
        }
        Intent intent = new Intent(Intent.ACTION_VIEW);
        intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
        intent.setDataAndType(Uri.parse("file://" + apkFile.toString()), "application/vnd.android.package-archive");
        mContext.startActivity(intent);
    }

    /**
     * 获取当前版本号
     */
    private double getVersionName() {
        // 获取packagemanager的实例  
        PackageManager packageManager = mContext.getPackageManager();
        // getPackageName()是你当前类的包名，0代表是获取版本信息  
        PackageInfo packInfo = null;
        try {
            packInfo = packageManager.getPackageInfo(mContext.getPackageName(), 0);
        } catch (NameNotFoundException e) {
            e.printStackTrace();
        }
        return Double.parseDouble(packInfo.versionName);
    }
}

**这里主要是介绍的一些主要方法 ，布局、版本比较和获取权限代码就不在贴出来了，想了解更多的童鞋可以打开这个链接http://download.csdn.net/download/u012941592/10037918