android app版本更新

1.首先整理一下思路
→在tomcat的目录中存放一个apk文件
→android客户端发送请求验证版本是否为最新版本
→如果不是最新版本（看业务需求是直接强制更新，还是提示用户自助更新）
→启动google官方提供的DownloadManager给与参数启动下载并安装（封装了工具类）
2.我百度了一些代码封装进了工具类中
以下是我搬运代码的地址
https://blog.csdn.net/u010296640/article/details/73496690/
https://blog.csdn.net/d_o_n_g2/article/details/78028237
https://www.jianshu.com/p/6816977bfdeb

//工具类
package com.smartonet.utils;

import android.app.DownloadManager;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.database.Cursor;
import android.net.Uri;
import android.os.Environment;
import android.widget.Toast;

/**
 * Created by hanzh on 2018/9/10.
 */
public class DownLoadUtils {
    //下载器
    private DownloadManager downloadManager;
    //上下文
    private Context mContext;
    //下载的ID
    private long downloadId;

    public  DownLoadUtils(Context context){
        this.mContext = context;
    }

    //下载apk
    public void downloadAPK(String url, String name) {
        //创建下载任务
            DownloadManager.Request request = new DownloadManager.Request(Uri.parse(url));
        //移动网络情况下是否允许漫游
        request.setAllowedOverRoaming(false);
        //在通知栏中显示，默认就是显示的
        request.setNotificationVisibility(DownloadManager.Request.VISIBILITY_VISIBLE);
        request.setTitle("新版本Apk");
        request.setDescription("smartonet Downloading");
        request.setVisibleInDownloadsUi(true);
        //设置下载的路径
        request.setDestinationInExternalPublicDir(Environment.getExternalStorageDirectory().getAbsolutePath() , name);
        //获取DownloadManager
        downloadManager = (DownloadManager) mContext.getSystemService(Context.DOWNLOAD_SERVICE);
        //将下载请求加入下载队列，加入下载队列后会给该任务返回一个long型的id，通过该id可以取消任务，重启任务、获取下载的文件等等
        downloadId = downloadManager.enqueue(request);
        //注册广播接收者，监听下载状态
        mContext.registerReceiver(receiver,
                new IntentFilter(DownloadManager.ACTION_DOWNLOAD_COMPLETE));
    }

    //广播监听下载的各个状态
    private BroadcastReceiver receiver = new BroadcastReceiver() {
        @Override
        public void onReceive(Context context, Intent intent) {
            checkStatus();
        }
    };


    //检查下载状态
    private void checkStatus() {
        DownloadManager.Query query = new DownloadManager.Query();
        //通过下载的id查找
        query.setFilterById(downloadId);
        Cursor c = downloadManager.query(query);
        if (c.moveToFirst()) {
            int status = c.getInt(c.getColumnIndex(DownloadManager.COLUMN_STATUS));
            switch (status) {
                //下载暂停
                case DownloadManager.STATUS_PAUSED:
                    break;
                //下载延迟
                case DownloadManager.STATUS_PENDING:
                    break;
                //正在下载
                case DownloadManager.STATUS_RUNNING:
                    break;
                //下载完成
                case DownloadManager.STATUS_SUCCESSFUL:
                    //下载完成安装APK
                    installAPK();
                    break;
                //下载失败
                case DownloadManager.STATUS_FAILED:
                    Toast.makeText(mContext, "下载失败", Toast.LENGTH_SHORT).show();
                    break;
            }
        }
        c.close();
    }

    //下载到本地后执行安装
    private void installAPK() {
        //获取下载文件的Uri
        Uri downloadFileUri = downloadManager.getUriForDownloadedFile(downloadId);
        if (downloadFileUri != null) {
            Intent intent= new Intent(Intent.ACTION_VIEW);
            intent.setDataAndType(downloadFileUri, "application/vnd.android.package-archive");
            intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
            mContext.startActivity(intent);
            mContext.unregisterReceiver(receiver);
        }
    }

}

DownLoadUtils downloadUtils =   new DownLoadUtils(getContext());
                        downloadUtils.downloadAPK("http://ip地址:端口/服务名/resources/app/app-release.apk", "smartonet.apk");

在这里奉劝诸位千万别写个localhost上去！我苦恼了许久不知道为什么不行，结果发现自己写了localhost气得我想给自己脑袋来一下！！！