android调用系统选取文件，解析真实路径，再用选择第三方app打开各类文件。涉及到知识点有几个，这几天终于搞懂了，感谢网上大家的分享，自己需要总结下。
参考文章：
1、选取文件后的路径解析：https://www.jianshu.com/p/d53243528917
2、android手机路径的了解：https://www.jianshu.com/p/37448649244f
3、Android FileProvider 详解: https://blog.csdn.net/yingaizhu/article/details/118972148
4、打开各种格式的文件：https://blog.51cto.com/u_14397532/4930925
具体代码实现如下：
首先申请外部存储的读写权限：
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>
<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE"/>
一、调用系统文件选择器来选择文件
lateinit var fileChoose: ActivityResultLauncher<String>;
var curFilePath: String? = null
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContentView(R.layout.activity_main)
val button = findViewById<Button>(R.id.btn)
button.setOnClickListener { selectFile() }
val openBtn = findViewById<Button>(R.id.openBtn)
openBtn.setOnClickListener {
openFile()
}
fileChoose = registerForActivityResult(GetContent()) { result ->
try {
//content://com.android.providers.media.documents /document/image%3A335
//content://com.android.providers.downloads.documents /document/raw%3A%2Fstorage%2Femulated%2F0%2FDownload%2FBrowser%2Fcom.apple.movetoios-3.2.6-universal-release.apk
//content://com.meizu.media.gallery.store /external/images/media/69
//content://com.android.providers.media.documents /document/video%3A41
//content://com.android.providers.downloads.documents /document/7
// println("========= =====result=>$result")
// println("========= =====path=>${result.path} host=>${result.host} scheme=>${result.scheme}")
findViewById<TextView>(R.id.text).text = result.path
var path = GetFilePathFromUri.getFileAbsolutePath(this@MainActivity, result)
findViewById<TextView>(R.id.abPath).text = path
curFilePath = path
} catch (e: Exception) {
println(e.printStackTrace())
}
}
}
private fun selectFile() {
// Intent intent = new Intent(Intent.ACTION_GET_CONTENT);
// intent.setType("*/*"); //无类型限制
// intent.addCategory(Intent.CATEGORY_OPENABLE);
fileChoose.launch("*/*")
}
registerForActivityResult需要在onCreate方法初始化，不然会报错的。
二、根据返回的content://XXXXX.XX路径，获取文件绝对路径，每个手机版本都不一样，分隔线是android4.4、10，
public class GetFilePathFromUri {
/**
* 文件路径名称
*/
public static String dirPathName = "appFiles";
/**
* 判断手机的外部存储是否有，如果没有就用内部存储
*
* @param context
* @param dir
* @return
*/
public static String getFileDirPath(Context context, String dir) {
String directoryPath = "";
if (MEDIA_MOUNTED.equals(Environment.getExternalStorageState())) {//判断外部存储是否可用
directoryPath = context.getExternalFilesDir(dir).getAbsolutePath();
} else {//没外部存储就使用内部存储
directoryPath = context.getFilesDir() + File.separator + dir;
}
File file = new File(directoryPath);
if (!file.exists()) {//判断文件目录是否存在
file.mkdirs();
}
return directoryPath;
}
/**
* 根据Uri获取文件绝对路径，解决Android4.4以上版本Uri转换 兼容Android 10
*
* @param context
* @param imageUri
*/
public static String getFileAbsolutePath(Context context, Uri imageUri) {
if (context == null || imageUri == null) {
return null;
}
//4.4以下的版本
if (android.os.Build.VERSION.SDK_INT < android.os.Build.VERSION_CODES.KITKAT) {
return getRealFilePath(context, imageUri);
} else if (android.os.Build.VERSION.SDK_INT >= android.os.Build.VERSION_CODES.KITKAT
&& android.os.Build.VERSION.SDK_INT < Build.VERSION_CODES.Q
&& DocumentsContract.isDocumentUri(context, imageUri)) {//大于4.4，小于10
if (isExternalStorageDocument(imageUri)) {
String docId = DocumentsContract.getDocumentId(imageUri);
String[] split = docId.split(":");
String type = split[0];
if ("primary".equalsIgnoreCase(type)) {
return Environment.getExternalStorageDirectory() + "/" + split[1];
}
} else if (isDownloadsDocument(imageUri)) {
String id = DocumentsContract.getDocumentId(imageUri);
if (!TextUtils.isEmpty(id)) {
if (id.startsWith("raw:")) {//已经返回真实路径
return id.replaceFirst("raw:", "");
}
}
Uri contentUri = ContentUris.withAppendedId(Uri.parse("content://downloads/public_downloads"), Long.valueOf(id));
return getDataColumn(context, contentUri, null, null);
} else if (isMediaDocument(imageUri)) {
String docId = DocumentsContract.getDocumentId(imageUri);
String[] split = docId.split(":");
String type = split[0];
Uri contentUri = null;
if ("image".equals(type)) {
contentUri = MediaStore.Images.Media.EXTERNAL_CONTENT_URI;
} else if ("video".equals(type)) {
contentUri = MediaStore.Video.Media.EXTERNAL_CONTENT_URI;
} else if ("audio".equals(type)) {
contentUri = MediaStore.Audio.Media.EXTERNAL_CONTENT_URI;
}
String selection = MediaStore.Images.Media._ID + "=?";
String[] selectionArgs = new String[]{split[1]};
return getDataColumn(context, contentUri, selection, selectionArgs);
}
} else if (android.os.Build.VERSION.SDK_INT >= Build.VERSION_CODES.Q) {// MediaStore (and general) 大于等于10
return uriToFileApiQ(context, imageUri);
} else if ("content".equalsIgnoreCase(imageUri.getScheme())) {
// Return the remote address
if (isGooglePhotosUri(imageUri)) {
return imageUri.getLastPathSegment();
}
if (Build.VERSION.SDK_INT >= 24) {
return getFilePathFromUri(context, imageUri); //content 类型
} else {
return getDataColumn(context, imageUri, null, null);
}
}
// File
else if ("file".equalsIgnoreCase(imageUri.getScheme())) {
return imageUri.getPath();
}
return null;
}
private static String getRealFilePath(final Context context, final Uri uri) {
if (null == uri) {
return null;
}
final String scheme = uri.getScheme();
String data = null;
if (scheme == null) {
data = uri.getPath();
} else if (ContentResolver.SCHEME_FILE.equals(scheme)) {
data = uri.getPath();
} else if (ContentResolver.SCHEME_CONTENT.equals(scheme)) {
String[] projection = {MediaStore.Images.ImageColumns.DATA};
Cursor cursor = context.getContentResolver().query(uri, projection, null, null, null);
if (null != cursor) {
if (cursor.moveToFirst()) {
int index = cursor.getColumnIndex(MediaStore.Images.ImageColumns.DATA);
if (index > -1) {
data = cursor.getString(index);
}
}
cursor.close();
}
}
return data;
}
/**
* @param uri The Uri to check.
* @return Whether the Uri authority is ExternalStorageProvider.
*/
private static boolean isExternalStorageDocument(Uri uri) {
return "com.android.externalstorage.documents".equals(uri.getAuthority());
}
/**
* @param uri The Uri to check.
* @return Whether the Uri authority is DownloadsProvider.
*/
private static boolean isDownloadsDocument(Uri uri) {
return "com.android.providers.downloads.documents".equals(uri.getAuthority());
}
private static String getDataColumn(Context context, Uri uri, String selection, String[] selectionArgs) {
Cursor cursor = null;
String column = MediaStore.Images.Media.DATA;
String[] projection = {column};
try {
cursor = context.getContentResolver().query(uri, projection, selection, selectionArgs, null);
if (cursor != null && cursor.moveToFirst()) {
int index = cursor.getColumnIndexOrThrow(column);
return cursor.getString(index);
}
} finally {
if (cursor != null) {
cursor.close();
}
}
return null;
}
/**
* @param uri The Uri to check.
* @return Whether the Uri authority is MediaProvider.
*/
private static boolean isMediaDocument(Uri uri) {
return "com.android.providers.media.documents".equals(uri.getAuthority());
}
/**
* @param uri The Uri to check.
* @return Whether the Uri authority is Google Photos.
*/
private static boolean isGooglePhotosUri(Uri uri) {
return "com.google.android.apps.photos.content".equals(uri.getAuthority());
}
/**
* Android 10 以上适配 另一种写法
*
* @param context
* @param uri
* @return
*/
@SuppressLint("Range")
private static String getFileFromContentUri(Context context, Uri uri) {
if (uri == null) {
return null;
}
String filePath;
String[] filePathColumn = {MediaStore.MediaColumns.DATA, MediaStore.MediaColumns.DISPLAY_NAME};
ContentResolver contentResolver = context.getContentResolver();
Cursor cursor = contentResolver.query(uri, filePathColumn, null,
null, null);
if (cursor != null) {
cursor.moveToFirst();
try {
filePath = cursor.getString(cursor.getColumnIndex(filePathColumn[0]));
return filePath;
} catch (Exception e) {
} finally {
cursor.close();
}
}
return "";
}
/**
* Android 10 以上适配
*
* @param context
* @param uri
* @return
*/
@RequiresApi(api = Build.VERSION_CODES.Q)
private static String uriToFileApiQ(Context context, Uri uri) {
File file = null;
//android10以上转换
if (uri.getScheme().equals(ContentResolver.SCHEME_FILE)) {
file = new File(uri.getPath());
} else if (uri.getScheme().equals(ContentResolver.SCHEME_CONTENT)) {
//把文件复制到沙盒目录
ContentResolver contentResolver = context.getContentResolver();
Cursor cursor = contentResolver.query(uri, null, null, null, null);
if (cursor.moveToFirst()) {
@SuppressLint("Range")
String displayName = cursor.getString(cursor.getColumnIndex(OpenableColumns.DISPLAY_NAME));
try {
InputStream is = contentResolver.openInputStream(uri);
// File file1 = new File(context.getExternalCacheDir().getAbsolutePath()+"/"+System.currentTimeMillis());
// if (!file1.exists()) {
// file1.mkdir();
// }
String dirPath = getFileDirPath(context, dirPathName);
File cache = new File(dirPath, displayName);
FileOutputStream fos = new FileOutputStream(cache);
FileUtils.copy(is, fos);
file = cache;
fos.close();
is.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
return file.getAbsolutePath();
}
private static String getFilePathFromUri(Context context, Uri uri) {
String realFilePath = getRealFilePath(context, uri); //防止获取不到真实的地址，因此这里需要进行判断
if (!TextUtils.isEmpty(realFilePath)) {
return realFilePath;
}
// File filesDir = context.getApplicationContext().getFilesDir();
String filesDir = getFileDirPath(context,dirPathName);
String fileName = getFileName(uri);
if (!TextUtils.isEmpty(fileName)) {
File copyFile1 = new File(filesDir + File.separator + fileName);
copyFile(context, uri, copyFile1);
return copyFile1.getAbsolutePath();
}
return null;
}
private static String getFileName(Uri uri) {
if (uri == null) {
return null;
}
String fileName = null;
String path = uri.getPath();
int cut = path.lastIndexOf('/');
if (cut != -1) {
fileName = path.substring(cut + 1);
}
return fileName;
}
private static void copyFile(Context context, Uri srcUri, File dstFile) {
try {
InputStream inputStream = context.getContentResolver().openInputStream(srcUri);
if (inputStream == null) {
return;
}
OutputStream outputStream = new FileOutputStream(dstFile);
copyStream(inputStream, outputStream);
inputStream.close();
outputStream.close();
} catch (Exception e) {
e.printStackTrace();
}
}
private static int copyStream(InputStream input, OutputStream output) {
final int BUFFER_SIZE = 1024 * 2;
byte[] buffer = new byte[BUFFER_SIZE];
BufferedInputStream in = new BufferedInputStream(input, BUFFER_SIZE);
BufferedOutputStream out = new BufferedOutputStream(output, BUFFER_SIZE);
int count = 0, n = 0;
try {
while ((n = in.read(buffer, 0, BUFFER_SIZE)) != -1) {
out.write(buffer, 0, n);
count += n;
}
out.flush();
} catch (Exception e) {
} finally {
try {
out.close();
in.close();
} catch (Exception e) {
}
}
return count;
}
}
三、根据文件的绝对路径，用手机自带的第三方app预览文件，android7.0及以上的需要用fileProvider，否则无法打开。
声明fileProvider在AndroidManifest.xml的application标签内
<provider
android:name="androidx.core.content.FileProvider"
android:authorities="${applicationId}"
android:exported="false"
android:grantUriPermissions="true">
<meta-data
android:name="android.support.FILE_PROVIDER_PATHS"
android:resource="@xml/file_paths_public" />
</provider>
在res目录新建xml资源文件夹，创建file_paths_public.xml,
<?xml version="1.0" encoding="utf-8"?>
<paths xmlns:android="http://schemas.android.com/apk/res/android">
<!--1、对应内部内存卡根目录：Context.getFileDir()-->
<files-path
name="int_root"
path="." />
<!--2、对应应用默认缓存根目录：Context.getCacheDir()-->
<cache-path
name="app_cache"
path="." />
<!--3、对应外部内存卡根目录：Environment.getExternalStorageDirectory()-->
<external-path
name="ext_root"
path="." />
<!--4、对应外部内存卡根目录下的APP公共目录：Context.getExternalFileDir(String)-->
<external-files-path
name="ext_pub"
path="." />
<!--5、对应外部内存卡根目录下的APP缓存目录：Context.getExternalCacheDir()-->
<external-cache-path
name="ext_cache"
path="." />
</paths>
最后一步打开该文件，把file路径转成content://XXXX/XX的uri，
fun openFile(){
try{
var intent = Intent("android.intent.action.VIEW");
intent.addCategory("android.intent.category.DEFAULT");
intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
var uri: Uri;
var file:File
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.N) {// 7.0及以上，需要用到provider
file = File("$curFilePath")
intent.setFlags(Intent.FLAG_GRANT_READ_URI_PERMISSION)//FLAG_GRANT_WRITE_URI_PERMISSION
uri = FileProvider.getUriForFile(this@MainActivity, "com.org.filechooseapp", file)
//使用fileProvider后，选择android10手机的某个文件，file路径转成content,如下：content://com.org.filechooseapp/ext_pub/appFiles/fd_tmp_file.txt
} else {
file = File("file://$curFilePath")
uri = Uri.fromFile(file)
}
intent.setDataAndType(uri, getMIMEType(file))
this.startActivity(intent)
}catch (e:Exception){
e.printStackTrace()
Toast.makeText(this@MainActivity,"文件打开失败",Toast.LENGTH_LONG).show()
}
}
/* 判断文件MimeType的method */
fun getMIMEType(f: File): String {
var type: String = ""
var fName: String = f.name
/* 取得扩展名 */
var end:String = fName.substring (fName.lastIndexOf(".") + 1, fName.length).lowercase(Locale.getDefault());
/* 按扩展名的类型决定MimeType */
if (end == "m4a" || end == "mp3" || end == "mid" || end == "xmf" || end == "ogg" || end == "wav" || end == "mpga") {
return "audio/*";
} else if (end == "3gp" || end == "mp4" || end == "mpg4" || end == "mov") {
return "video/*";
} else if (end == "jpg" || end == "gif" || end == "png" || end == "jpeg" || end == "bmp") {
return "image/*";
} else if(end == "txt" || end == "log" || end == "xml"){
return "text/plain"
} else if(end == "pdf"){
return "application/pdf"
}else if(end == "doc"){
return "application/msword"
}else if(end == "docx"){
return "application/vnd.openxmlformats-officedocument.wordprocessingml.document"
}else if(end == "xls"){
return "application/vnd.ms-excel"
}else if(end == "xlsx"){
return "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet"
}else if(end == "exe"){
return "application/octet-stream"
} else if(end == "ppt"){
return "application/vnd.ms-powerpoint"
}else if(end == "pptx"){
return "application/vnd.openxmlformats-officedocument.presentationml.presentation"
}else if(end == "tar"){
return "application/x-tar"
}else if(end == "tgz"){
return "application/x-compressed"
}else if(end == "zip"){
return "application/x-zip-compressed"
}
else if (end == "apk") {
/* android.permission.INSTALL_PACKAGES */
//用下载并自动安装apk包
return "application/vnd.android.package-archive"
} else {
/* 如果无法直接打开，就弹出软件列表给用户选择 */
return "*/*"
}
}
// private final String[][] MIME_MapTable={
////{后缀名，MIME类型}
// {".3gp", "video/3gpp"},
// {".apk", "application/vnd.android.package-archive"},
// {".asf", "video/x-ms-asf"},
// {".avi", "video/x-msvideo"},
// {".bin", "application/octet-stream"},
// {".bmp", "image/bmp"},
// {".c", "text/plain"},
// {".class", "application/octet-stream"},
// {".conf", "text/plain"},
// {".cpp", "text/plain"},
// {".doc", "application/msword"},
// {".docx", "application/vnd.openxmlformats-officedocument.wordprocessingml.document"},
// {".xls", "application/vnd.ms-excel"},
// {".xlsx", "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet"},
// {".exe", "application/octet-stream"},
// {".gif", "image/gif"},
// {".gtar", "application/x-gtar"},
// {".gz", "application/x-gzip"},
// {".h", "text/plain"},
// {".htm", "text/html"},
// {".html", "text/html"},
// {".jar", "application/java-archive"},
// {".java", "text/plain"},
// {".jpeg", "image/jpeg"},
// {".jpg", "image/jpeg"},
// {".js", "application/x-javascript"},
// {".log", "text/plain"},
// {".m3u", "audio/x-mpegurl"},
// {".m4a", "audio/mp4a-latm"},
// {".m4b", "audio/mp4a-latm"},
// {".m4p", "audio/mp4a-latm"},
// {".m4u", "video/vnd.mpegurl"},
// {".m4v", "video/x-m4v"},
// {".mov", "video/quicktime"},
// {".mp2", "audio/x-mpeg"},
// {".mp3", "audio/x-mpeg"},
// {".mp4", "video/mp4"},
// {".mpc", "application/vnd.mpohun.certificate"},
// {".mpe", "video/mpeg"},
// {".mpeg", "video/mpeg"},
// {".mpg", "video/mpeg"},
// {".mpg4", "video/mp4"},
// {".mpga", "audio/mpeg"},
// {".msg", "application/vnd.ms-outlook"},
// {".ogg", "audio/ogg"},
// {".pdf", "application/pdf"},
// {".png", "image/png"},
// {".pps", "application/vnd.ms-powerpoint"},
// {".ppt", "application/vnd.ms-powerpoint"},
// {".pptx", "application/vnd.openxmlformats-officedocument.presentationml.presentation"},
// {".prop", "text/plain"},
// {".rc", "text/plain"},
// {".rmvb", "audio/x-pn-realaudio"},
// {".rtf", "application/rtf"},
// {".sh", "text/plain"},
// {".tar", "application/x-tar"},
// {".tgz", "application/x-compressed"},
// {".txt", "text/plain"},
// {".wav", "audio/x-wav"},
// {".wma", "audio/x-ms-wma"},
// {".wmv", "audio/x-ms-wmv"},
// {".wps", "application/vnd.ms-works"},
// {".xml", "text/plain"},
// {".z", "application/x-compress"},
// {".zip", "application/x-zip-compressed"},
// {"", "*/*"}
// };
