Android下载apk并安装apk（用于软件版本升级用途）
软件版本更新是每个应用必不可少的功能，基本实现方案是请求服务器最新的版本号与本地的版本号对比，有新版本则下载apk并执行安装。请求服务器版本号与本地对比很容易，本文就不过多讲解，主要讲解下载apk到安装apk的内容。
一、所需权限
<!--请求安装APK的权限-->
<uses-permission android:name="android.permission.REQUEST_INSTALL_PACKAGES" />
<!--写如外部存储的权限-->
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>
<!--读取外部存储的权限-->
<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE"/>
<!--网络权限-->
<uses-permission android:name="android.permission.INTERNET"/>
（1）读写外部存储的权限需要动态申请，详见：Android动态获取权限
（2）安装apk的权限从Android8.0开始需要每个应用独立开启
//跳转到开启apk安装权限开启的界面，让用户手动打开
Intent intent = new Intent(Settings.ACTION_MANAGE_UNKNOWN_APP_SOURCES,Uri.parse("package:" +getPackageName()));
intentActivityResultLauncher.launch(intent);
二、代码实现
（1）注册provider
在AndroidManifest.xml中声明provider
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"xmlns:tools="http://schemas.android.com/tools"package="你的包名"><!--省略属性。。。--><application省略属性。。。><activity省略属性。。。><!--声明provider--><providerandroid:name="androidx.core.content.FileProvider"android:authorities="你的包名.fileprovider"android:exported="false"android:grantUriPermissions="true"><meta-dataandroid:name="android.support.FILE_PROVIDER_PATHS"android:resource="@xml/filepaths" /></provider></application></manifest>
在res的xml目录增加filepaths.xml
filepaths.xml中配置path路径
<paths xmlns:android="http://schemas.android.com/apk/res/android"><path><root-path name="files_apk"path="/"/></path>
</paths>
（2）动态申请权限基础BaseActivity
这个类在另外一篇文章中讲解，主要为了方便动态获取权限。
package com.soface.versioncontroll;import android.content.pm.PackageManager;
import android.os.Build;import androidx.annotation.NonNull;
import androidx.appcompat.app.AppCompatActivity;
import androidx.core.app.ActivityCompat;
import androidx.core.content.ContextCompat;import java.util.ArrayList;
import java.util.List;public class BaseActivity extends AppCompatActivity {public static final int REQUEST_CONDE =0xFFFF;/*** 动态请求权限(入口)* @param permissionNameList 需要授权的权限名称*/public void requestPermission(List<String> permissionNameList){// TODO: 2023/2/22 第一步：排除（已经获得过授权的权限）=============================================================List<String> UnauthorizedPermissionNameList = new ArrayList<>();//用于存放未获得授权的权限for (String permission : permissionNameList){//检查每个权限是否已经获得授权int checkResult=ContextCompat.checkSelfPermission(this,permission);if (checkResult==PackageManager.PERMISSION_GRANTED){//已获得过授权,直接抛出结果truethrowPermissionResults(permission,true);}else if (checkResult==PackageManager.PERMISSION_DENIED) {//未获得授权，把未获得授权的权限加入到thisPermissionNames中，待下一步请求UnauthorizedPermissionNameList.add(permission);}else {//按道理，这里永远不会发生，//因为checkSelfPermission方法说得很清楚，只会返回PERMISSION_GRANTED或者PERMISSION_DENIED//但是为了严谨，以防万一，还是给它抛出结果falsethrowPermissionResults("Unknown_result",false);}}if (UnauthorizedPermissionNameList.size()==0)return;//表示：全部已经拥有全选，不用往下执行// TODO: 2023/2/22 第二步：开始申请权限==========================================================================if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {//由于请求权限的参数必须是String[],所以List转到String[]中String[] UnauthorizedPermissionNames=new String[UnauthorizedPermissionNameList.size()];for (int k=0;k<UnauthorizedPermissionNameList.size();k++){UnauthorizedPermissionNames[k]=UnauthorizedPermissionNameList.get(k);}//请求权限ActivityCompat.requestPermissions(this, UnauthorizedPermissionNames, REQUEST_CONDE);}else {//低版本的Android不需要动态获取权限，这里直接抛出结果truethrowPermissionResults("Below_VERSION_M",true);}}/*** 抛出授权结果（出口）* @param permissionName 权限名称* @param isSuccess 该权限是否获得授权（true:获得授权 false:未获得授权）*/public void throwPermissionResults(String permissionName, boolean isSuccess){// TODO: 2023/2/22 这里如果isSuccess=false,可以自定义一个弹窗，让用户选择// 到底是要直接退出应用，还是去设置中开启权限,本文主要是总结动态获取权限，所以弹窗笔者就不写了}@Overridepublic void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {super.onRequestPermissionsResult(requestCode, permissions, grantResults);//判断我们的请求码，避免别的事件调用onRequestPermissionsResult,导致我们拿到本不该属于我们的数据if (requestCode==REQUEST_CONDE){// 如果请求被取消，则结果数组为空。if (grantResults.length > 0) {//循环一个一个地去判断结果for (int k=0;k<permissions.length;k++){if (grantResults[k] == PackageManager.PERMISSION_GRANTED){// 权限请求成功，抛出结果truethrowPermissionResults(permissions[k],true);}if (grantResults[k] == PackageManager.PERMISSION_DENIED){// 权限请求失败，抛出结果falsethrowPermissionResults(permissions[k],false);}}} else {//没有任何授权结果,直接抛出结果falsethrowPermissionResults("Unknown_result",false);}}}}
（3）判断需不需要升级最新软件的MainActivity
package com.soface.versioncontroll;import androidx.activity.result.ActivityResultLauncher;
import androidx.activity.result.contract.ActivityResultContracts;
import androidx.appcompat.app.AppCompatActivity;import android.Manifest;
import android.content.Intent;
import android.net.Uri;
import android.os.Build;
import android.os.Bundle;
import android.provider.Settings;
import android.util.Log;
import android.view.View;
import android.widget.Button;import java.util.ArrayList;
import java.util.List;public class MainActivity extends BaseActivity{@Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.activity_main);//动态请求权限List<String> perList=new ArrayList<>();perList.add(Manifest.permission.WRITE_EXTERNAL_STORAGE);perList.add(Manifest.permission.READ_EXTERNAL_STORAGE);perList.add(Manifest.permission.INTERNET);requestPermission(perList);//初始化结果返回接听initActivityResult();Button permission=(Button) findViewById(R.id.permission);permission.setOnClickListener(new View.OnClickListener() {@Overridepublic void onClick(View v) {//当判断需要升级最新软件，则调用这个方法，这里为了方便测试，放在点击事件中openSetting();}});}@Overridepublic void onDestroy() {super.onDestroy();stop();}@Overridepublic void throwPermissionResults(String permissionName, boolean isSuccess) {super.throwPermissionResults(permissionName, isSuccess);//拿到相应的权限，以及授权结果switch (permissionName){case Manifest.permission.WRITE_EXTERNAL_STORAGE:Log.d("fxHou","WRITE_EXTERNAL_STORAGE授权结果："+isSuccess);break;case Manifest.permission.READ_EXTERNAL_STORAGE:Log.d("fxHou","READ_EXTERNAL_STORAGE授权结果："+isSuccess);break;default:break;}}public void openSetting() {if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {//Android 8.0以上if(!getPackageManager().canRequestPackageInstalls()){//权限没有打开，跳转界面，提示用户去手动打开Intent intent = new Intent(Settings.ACTION_MANAGE_UNKNOWN_APP_SOURCES,Uri.parse("package:" +getPackageName()));intentActivityResultLauncher.launch(intent);}else {//已经拥有权限，直接执行下载apk操作start();}}else {//开始下载安装start();}}private ActivityResultLauncher<Intent> intentActivityResultLauncher;private void initActivityResult() {intentActivityResultLauncher = registerForActivityResult(new ActivityResultContracts.StartActivityForResult(), result -> {if (result.getResultCode() == AppCompatActivity.RESULT_OK) {//开始下载安装start();}});}VersionControl versionControl;String downloadUrl="http://www.soface.top:8080/source/Public/ApkVersionControl/chart.apk";String titleStr="麦麦商家版V1.1.2";String contentStr="正在下载中，请耐心等待";//开始执行版本更新操作public void start(){//初始化版本控制versionControl=new VersionControl();versionControl.download(this,downloadUrl,titleStr,contentStr);versionControl.registerReceiver(this);}//停止执行版本更新操作public void stop(){//初始化版本控制versionControl.unRegisterReceiver(MainActivity.this);versionControl=null;}
}
（4）下载apk和安装apk的实现类
package com.soface.versioncontroll;import static android.content.Context.DOWNLOAD_SERVICE;import android.annotation.SuppressLint;
import android.app.Activity;
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.Build;
import android.os.Environment;
import android.provider.Settings;
import android.util.Log;import androidx.activity.result.ActivityResultLauncher;
import androidx.activity.result.contract.ActivityResultContracts;
import androidx.appcompat.app.AppCompatActivity;
import androidx.core.content.FileProvider;import java.io.File;public class VersionControl {//第一步: 下载APKprivate long downloadId=-1;private DownloadManager downloadManager;public void download(Context context,String url,String titleStr,String contentStr) {//创建下载任务DownloadManager.Request request = new DownloadManager.Request(Uri.parse(url));//在通知栏中显示，默认就是显示的request.setNotificationVisibility(DownloadManager.Request.VISIBILITY_VISIBLE);request.setTitle(titleStr);request.setDescription(contentStr);//设置下载的路径File file = new File(context.getExternalFilesDir(Environment.DIRECTORY_DOWNLOADS), "chart.apk");request.setDestinationUri(Uri.fromFile(file));file.getAbsolutePath();//获取DownloadManagerdownloadManager = (DownloadManager)context.getSystemService(DOWNLOAD_SERVICE);//将下载请求放入队列downloadId = downloadManager.enqueue(request);}//第二步: 监听下载结果private BroadcastReceiver broadcastReceiver;public void registerReceiver(Context context) {// 注册广播监听系统的下载完成事件。IntentFilter intentFilter = new IntentFilter(DownloadManager.ACTION_DOWNLOAD_COMPLETE);broadcastReceiver = new BroadcastReceiver() {@Overridepublic void onReceive(Context context, Intent intent) {long thisDownloadId = intent.getLongExtra(DownloadManager.EXTRA_DOWNLOAD_ID, -1);if (thisDownloadId!=-1 && downloadId!=-1){if (thisDownloadId == downloadId) {//下载完成，检查下载状态checkStatus(context);}}}};context.registerReceiver(broadcastReceiver, intentFilter);}public void unRegisterReceiver(Context context){if (broadcastReceiver!=null) {context.unregisterReceiver(broadcastReceiver);}}//第三部: 检查下载状态，是否下载成功@SuppressLint("Range")private void checkStatus(Context context) {DownloadManager.Query query = new DownloadManager.Query();// 执行查询, 返回一个 Cursor (相当于查询数据库)Cursor cursor = downloadManager.query(query);if (!cursor.moveToFirst()) {cursor.close();}int id = cursor.getInt(cursor.getColumnIndex(DownloadManager.COLUMN_ID));//通过下载的id查找query.setFilterById(id);// 获取下载好的 apk 路径String localFilename = null;if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.N) {localFilename = cursor.getString(cursor.getColumnIndex(DownloadManager.COLUMN_LOCAL_URI));} else {localFilename = cursor.getString(cursor.getColumnIndex(DownloadManager.COLUMN_LOCAL_FILENAME));}if (cursor.moveToFirst()) {int status = cursor.getInt(cursor.getColumnIndex(DownloadManager.COLUMN_STATUS));switch (status) {case DownloadManager.STATUS_PAUSED://下载暂停Log.d("fxHou","下载暂停");break;case DownloadManager.STATUS_PENDING://下载延迟Log.d("fxHou","下载延迟");break;case DownloadManager.STATUS_RUNNING://正在下载Log.d("fxHou","正在下载");break;case DownloadManager.STATUS_SUCCESSFUL://下载完成安装APKinstallApk(context,localFilename);cursor.close();break;case DownloadManager.STATUS_FAILED://下载失败Log.d("fxHou","下载失败");cursor.close();break;default:break;}}}//第四部: 安装apkprivate void installApk(Context context,String path) {Intent intent = new Intent(Intent.ACTION_VIEW);intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);File file = new File(Uri.parse(path).getPath());if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.N) {intent.setFlags(Intent.FLAG_GRANT_READ_URI_PERMISSION);Uri uri = FileProvider.getUriForFile(context, "你的包名.fileprovider", file);intent.setDataAndType(uri, "application/vnd.android.package-archive");} else {intent.setDataAndType(Uri.fromFile(file), "application/vnd.android.package-archive");}context.startActivity(intent);}}