一、配置拍照和读写权限

<uses-permission android:name="android.permission.CAMERA"/>
<uses-feature android:name="android.hardware.camera" />

<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>
<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE"/>
<uses-permission android:name="android.permission.MANAGE_EXTERNAL_STORAGE"/>

二、手动申请权限

        implementation 'com.permissionx.guolindev:permissionx:1.4.0'

        1、手动申请读写，拍照权限

PermissionX.init(this)
    .permissions(Manifest.permission.WRITE_EXTERNAL_STORAGE,
                    Manifest.permission.READ_EXTERNAL_STORAGE,
                    Manifest.permission.CAMERA)
            .request((allGranted, grantedList, deniedList) -> {
                if(allGranted){

                }
            });

        2、手动申请文件管理权限

if (Build.VERSION.SDK_INT >= 30 && !Environment.isExternalStorageManager()) {
    Intent intent = new Intent(Settings.ACTION_MANAGE_APP_ALL_FILES_ACCESS_PERMISSION);
    intent.setData(Uri.parse("package:" + getPackageName()));
    startActivity(intent);
}

三、Manifest中配置queries（解决resolveActivity为null）

<application
    ...>
    ...
</application>

<queries>
    <intent>
        <action android:name="android.media.action.IMAGE_CAPTURE"/>
    </intent>
    <intent>
        <action android:name="android.media.action.VIDEO_CAPTURE"/>
    </intent>
</queries>

四、Manifest中配置provider

<application
    ...>
    <provider
        android:name="androidx.core.content.FileProvider"
        android:authorities="你的package包名.fileprovider"
        android:exported="false"
        android:grantUriPermissions="true"
        tools:replace="android:authorities">
        <meta-data
            android:name="android.support.FILE_PROVIDER_PATHS"
            tools:replace="android:resource"
            android:resource="@xml/file_paths" />
    </provider>
</application>

五、配置file_paths文件

<?xml version="1.0" encoding="utf-8"?>
<paths>
    <!--目录为：Environment.getExternalStorageDirectory()-->
    <external-path
        name="download"
        path="Download" />

    <external-path name="external_files" path="." />
</paths>

六、调用相机（FileUtil类）

public class FileUtil {
    public static String takePhoto(Activity activity) { //照相
        //调用相机
        Intent takePhotoIntent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);//用来打开相机的Intent
        if(takePhotoIntent.resolveActivity(activity.getPackageManager())!=null){
            //Constant.PIC_DIR = Environment.getExternalStorageDirectory().getAbsolutePath()+"/Download"
            File file=new File(Constant.PIC_DIR);
            if(!file.exists())file.mkdir();
            // 保存路径
            file = getFile(Constant.PIC_DIR, System.currentTimeMillis()+ ".jpg");
            Uri uri;
            if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.N) {
                //设置7.0以上共享文件，分享路径定义在xml/file_paths.xml
                uri = FileProvider.getUriForFile(activity, "你的package包名.fileprovider", file);
            } else {
                // 7.0以下,共享文件
                uri = Uri.fromFile(file);   // 将路径转换为Uri对象
            }
            takePhotoIntent.putExtra(MediaStore.EXTRA_OUTPUT, uri);    // 表示录制完后保存的录制，如果不写，则会保存到默认的路径，在onActivityResult()的回调，通过intent.getData中返回保存的路径
            //Constant.REQ_CODE为任意整数，用于回调
            activity.startActivityForResult(takePhotoIntent, Constant.REQ_CODE);  // 跳转
            return file.getAbsolutePath();
        }
        return null;
    }

    public static File getFile(String filePath, String fileName){
        File dir = new File(filePath);
        if (!dir.exists()){//如果不存在，进行创建
            dir.mkdirs();
        }
        File soundFile = new File(dir,fileName);
        if (!soundFile.exists()){
            try {
                soundFile.createNewFile();
            }catch (IOException e){
                e.printStackTrace();
            }
        }
        return soundFile;
    }

    //通过URI获取file
    public static File getFileFromContentUri(Uri contentUri, Context context) {
        if (contentUri == null) {
            return null;
        }
        File file = null;
        String filePath;
        String[] projection = { MediaStore.Files.FileColumns.DATA };
        ContentResolver contentResolver = context.getContentResolver();
        Cursor cursor = contentResolver.query(contentUri, projection, null,
                null, null);
        if (cursor != null && cursor.moveToFirst()) {
            filePath = cursor.getString(0);
            cursor.close();
            if (!filePath.isEmpty()) {
                file = new File(filePath);
            }
        }
        return file;
    }
}

七、处理拍照 / 本地图片回调（Activity类）

private String curSelectPhoto = "";

//启动相机
private void takePhoto(){
    curSelectPhoto = FileUtil.takePhoto(this);
}

//从本地获取图片
private void getPhotoFromLocal(){
    Intent i = new Intent();
    i.setAction(Intent.ACTION_PICK);
    i.setType("image/*");
    //Constant.PHOTO_LOCAL为任意整数，用于获取本地图片回调
    startActivityForResult(i, Constant.PHOTO_LOCAL);
}

@Override
public void onActivityResult(final int requestCode, int resultCode, final Intent data) {
    super.onActivityResult(requestCode,resultCode,data);
    if(resultCode==RESULT_OK){
        ThreadManager.getThreadPool().exeute(() -> {
            File file=null;
            if(requestCode==Constant.REQ_CODE){    //拍照
                file = new File(curSelectPhoto);
            }else{  //从本地上传
                Uri uri = data.getData();  //图片的保存路径
                file = FileUtil.getFileFromContentUri(uri,getApplicationContext());
            }
        });
    }
}