选择文件的时候，如果使用的是第三方软件，一般是直接返回绝对路径的Uri，如果是系统的，则会返回媒体库的xxxx，所以单纯一种方式选择文件，很可能拿到的绝对路径是错的或者是空的，所以需要做几种处理，这里参考博客：https://www.cnblogs.com/panhouye/archive/2017/04/23/6751710.html
下面是我弄好的一个选择文件的Activity，为了方便，使用了静态变量设置回调接口，所以直接调用startActivity方法，即可启动选择文件流程，并在回调接口中返回选中的文件的绝对路径，非常方便。
import android.annotation.SuppressLint;
import android.app.Activity;
import android.content.ContentResolver;
import android.content.ContentUris;
import android.content.Context;
import android.content.Intent;
import android.database.Cursor;
import android.net.Uri;
import android.os.Build;
import android.os.Environment;
import android.provider.DocumentsContract;
import android.provider.MediaStore;
import android.text.TextUtils;
import android.widget.Toast;
import com.imxiaoyu.common.base.ui.BaseActivity;
import com.imxiaoyu.common.impl.OnStringListener;
import com.imxiaoyu.common.utils.ALog;
import com.imxiaoyu.common.utils.ToastUtils;
import java.io.File;
import com.example.mp3editor.R;
import com.example.mp3editor.common.impl.OnMusicListener;
import com.example.mp3editor.common.util.MusicUtil;
import com.example.mp3editor.module.index.entity.MusicEntity;
/**
* 选择音乐文件
* Created by Admin on 2017/11/18.
*/
public class SelectFileActivity extends BaseActivity {undefined
/**
* 常量
*/
public final static int FILE_SELECT_CODE = 0x100;
public final static String ACTIVITY_TYPE = “ACTIVITY_TYPE”;
/**
* 变量
*/
private int type = 0;//0-音乐 1-视频
/**
* 接口
*/
private static OnStringListener onStringListener;
@Override
protected int getLayoutId() {undefined
return R.layout.activity_select_file;
}
public static void startActivity(Activity activity, OnMusicListener listener) {undefined
activity.startActivity(new Intent(activity, SelectFileActivity.class));
}
public static void startActivity(Activity activity, int type, OnStringListener listener) {undefined
onStringListener = listener;
Intent intent = new Intent(activity, SelectFileActivity.class);
intent.putExtra(ACTIVITY_TYPE, type);
activity.startActivity(intent);
}
@Override
protected void initData() {undefined
type = getIntent().getIntExtra(ACTIVITY_TYPE, 0);
}
@Override
protected void initView() {undefined
}
@Override
protected void onCreateActivity() {undefined
selectFile();
}
public void finish() {undefined
onStringListener = null;
super.finish();
}
/**
* 调用文件选择软件来选择文件
**/
public void selectFile() {undefined
Intent intent = new Intent(Intent.ACTION_GET_CONTENT);
if (type == 0) {undefined
intent.setType(“audio/*”);
} else {undefined
intent.setType(“video/*”);
}
intent.addCategory(Intent.CATEGORY_OPENABLE);
try {undefined
startActivityForResult(Intent.createChooser(intent, getString(R.string.please_select_a_file)), FILE_SELECT_CODE
);
} catch (android.content.ActivityNotFoundException ex) {undefined
// Potentially direct the user to the Market with a Dialog
Toast.makeText(getActivity(), getString(R.string.please_install_the_file_manager), Toast.LENGTH_SHORT)
.show();
}
}
/**
* 根据返回选择的文件，来进行上传操作
**/
@Override
public void onActivityResult(int requestCode, int resultCode, Intent data) {undefined
if (resultCode == Activity.RESULT_OK) {undefined
String path;
Uri uri = data.getData();
if (“file”.equalsIgnoreCase(uri.getScheme())) {//使用第三方应用打开
path = uri.getPath();
callback(path);
return;
}
if (Build.VERSION.SDK_INT > Build.VERSION_CODES.KITKAT) {//4.4以后
path = getPath(this, uri);
callback(path);
} else {//4.4以下下系统调用方法
path = getRealPathFromURI(uri);
callback(path);
}
}
super.onActivityResult(requestCode, resultCode, data);
}
private void callback(String path) {undefined
if (onStringListener != null) {undefined
onStringListener.onClick(path);
}
finish();
}
public String getRealPathFromURI(Uri contentUri) {undefined
String res = null;
String[] proj = { MediaStore.Images.Media.DATA };
Cursor cursor = getContentResolver().query(contentUri, proj, null, null, null);
if(null!=cursor&&cursor.moveToFirst()){;
int column_index = cursor.getColumnIndexOrThrow(MediaStore.Images.Media.DATA);
res = cursor.getString(column_index);
cursor.close();
}
return res;
}
/**
* 专为Android4.4设计的从Uri获取文件绝对路径，以前的方法已不好使
*/
@SuppressLint(“NewApi”)
public String getPath(final Context context, final Uri uri) {undefined
final boolean isKitKat = Build.VERSION.SDK_INT >= Build.VERSION_CODES.KITKAT;
// DocumentProvider
if (isKitKat && DocumentsContract.isDocumentUri(context, uri)) {undefined
// ExternalStorageProvider
if (isExternalStorageDocument(uri)) {undefined
final String docId = DocumentsContract.getDocumentId(uri);
final String[] split = docId.split(“:”);
final String type = split[0];
if (“primary”.equalsIgnoreCase(type)) {undefined
return Environment.getExternalStorageDirectory() + “/” + split[1];
}
}
// DownloadsProvider
else if (isDownloadsDocument(uri)) {undefined
final String id = DocumentsContract.getDocumentId(uri);
final Uri contentUri = ContentUris.withAppendedId(
Uri.parse(“content://downloads/public_downloads”), Long.valueOf(id));
return getDataColumn(context, contentUri, null, null);
}
// MediaProvider
else if (isMediaDocument(uri)) {undefined
final String docId = DocumentsContract.getDocumentId(uri);
final String[] split = docId.split(“:”);
final String type = split[0];
Uri contentUri = null;
if (“image”.equals(type)) {undefined
contentUri = MediaStore.Images.Media.EXTERNAL_CONTENT_URI;
} else if (“video”.equals(type)) {undefined
contentUri = MediaStore.Video.Media.EXTERNAL_CONTENT_URI;
} else if (“audio”.equals(type)) {undefined
contentUri = MediaStore.Audio.Media.EXTERNAL_CONTENT_URI;
}
final String selection = “_id=?”;
final String[] selectionArgs = new String[]{split[1]};
return getDataColumn(context, contentUri, selection, selectionArgs);
}
}
// MediaStore (and general)
else if (“content”.equalsIgnoreCase(uri.getScheme())) {undefined
return getDataColumn(context, uri, null, null);
}
// File
else if (“file”.equalsIgnoreCase(uri.getScheme())) {undefined
return uri.getPath();
}
return null;
}
/**
* Get the value of the data column for this Uri. This is useful for
* MediaStore Uris, and other file-based ContentProviders.
*
* @param context The context.
* @param uri The Uri to query.
* @param selection (Optional) Filter used in the query.
* @param selectionArgs (Optional) Selection arguments used in the query.
* @return The value of the _data column, which is typically a file path.
*/
public String getDataColumn(Context context, Uri uri, String selection,
String[] selectionArgs) {undefined
Cursor cursor = null;
final String column = “_data”;
final String[] projection = {column};
try {undefined
cursor = context.getContentResolver().query(uri, projection, selection, selectionArgs,
null);
if (cursor != null && cursor.moveToFirst()) {undefined
final int column_index = cursor.getColumnIndexOrThrow(column);
return cursor.getString(column_index);
}
} finally {undefined
if (cursor != null)
cursor.close();
}
return null;
}
/**
* @param uri The Uri to check.
* @return Whether the Uri authority is ExternalStorageProvider.
*/
public boolean isExternalStorageDocument(Uri uri) {undefined
return “com.android.externalstorage.documents”.equals(uri.getAuthority());
}
/**
* @param uri The Uri to check.
* @return Whether the Uri authority is MediaProvider.
*/
public boolean isMediaDocument(Uri uri) {undefined
return “com.android.providers.media.documents”.equals(uri.getAuthority());
}
/**
* @param uri The Uri to check.
* @return Whether the Uri authority is DownloadsProvider.
*/
public boolean isDownloadsDocument(Uri uri) {undefined
return “com.android.providers.downloads.documents”.equals(uri.getAuthority());
}
}