android.os.FileUriExposedException: file:///storag

问题:

I am trying to take a photo from the phone's camera using this code:

activity_main.xml:

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:orientation="vertical" >

    <Button
        android:id="@+id/btnCapture"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Camera" />

</LinearLayout>

MainActivity.java:

public class CameraDemoActivity extends Activity {
    int TAKE_PHOTO_CODE = 0;
    public static int count = 0;

    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState)
    {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);

        // Here, we are making a folder named picFolder to store
        // pics taken by the camera using this application.
        final String dir = Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_PICTURES) + "/picFolder/";
        File newdir = new File(dir);
        newdir.mkdirs();

        Button capture = (Button) findViewById(R.id.btnCapture);
        capture.setOnClickListener(new View.OnClickListener() {
            public void onClick(View v) {

                // Here, the counter will be incremented each time, and the
                // picture taken by camera will be stored as 1.jpg,2.jpg
                // and likewise.
                count++;
                String file = dir+count+".jpg";
                File newfile = new File(file);
                try {
                    newfile.createNewFile();
                }
                catch (IOException e)
                {
                }

                Uri outputFileUri = Uri.fromFile(newfile);

                Intent cameraIntent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
                cameraIntent.putExtra(MediaStore.EXTRA_OUTPUT, outputFileUri);

                startActivityForResult(cameraIntent, TAKE_PHOTO_CODE);
            }
        });
    }

    @Override
    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
        super.onActivityResult(requestCode, resultCode, data);

        if (requestCode == TAKE_PHOTO_CODE && resultCode == RESULT_OK) {
            Log.d("CameraDemo", "Pic saved");
        }
    }
}

I also added these permissions to Manifest.xml:

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

But I get this error message:

android.os.FileUriExposedException: file:///storage/emulated/0/Pictures/picFolder/1.jpg exposed beyond app through ClipData.Item.getUri()

What is the problem and how can I fix it?

EDIT: this is the updated code:

MainActivity:

package com.m.textdetection;

import android.Manifest;
import android.content.Intent;
import android.content.pm.PackageManager;
import android.icu.text.SimpleDateFormat;
import android.net.Uri;
import android.os.Environment;
import android.provider.MediaStore;
import android.support.v4.app.ActivityCompat;
import android.support.v4.content.ContextCompat;
import android.support.v4.content.FileProvider;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.Button;
import android.widget.ImageView;

import java.io.File;
import java.io.IOException;
import java.util.Date;

public class MainActivity extends AppCompatActivity {

    private MyTessOCR mTessOCR = new MyTessOCR(MainActivity.this);

    private Button takePictureButton;
    private ImageView imageView;


    /*
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        takePictureButton = (Button) findViewById(R.id.button_image);
        imageView = (ImageView) findViewById(R.id.imageview);

        if (ContextCompat.checkSelfPermission(this, Manifest.permission.CAMERA) != PackageManager.PERMISSION_GRANTED) {
            takePictureButton.setEnabled(false);
            ActivityCompat.requestPermissions(this, new String[] { Manifest.permission.CAMERA, Manifest.permission.WRITE_EXTERNAL_STORAGE }, 0);
        }
    }


    @Override
    public void onRequestPermissionsResult(int requestCode, String[] permissions, int[] grantResults) {
        if (requestCode == 0) {
            if (grantResults.length > 0 && grantResults[0] == PackageManager.PERMISSION_GRANTED
                    && grantResults[1] == PackageManager.PERMISSION_GRANTED) {
                takePictureButton.setEnabled(true);
            }
        }
    }

    public void takePicture(View view) {
        Intent intent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
        file = Uri.fromFile(getOutputMediaFile());
        intent.putExtra(MediaStore.EXTRA_OUTPUT, file);

        startActivityForResult(intent, 100);
    }

    @Override
    protected void onActivityResult(int requestCode, int resultCode, Intent data)
    {
        if (requestCode == 100) {
            if (resultCode == RESULT_OK) {
                imageView.setImageURI(File);
            }
        }
    }

    private static File getOutputMediaFile(){
        File mediaStorageDir = new File(Environment.getExternalStoragePublicDirectory(
                Environment.DIRECTORY_PICTURES), "CameraDemo");

        if (!mediaStorageDir.exists()){
            if (!mediaStorageDir.mkdirs()){
                return null;
            }
        }

        String timeStamp = new SimpleDateFormat("yyyyMMdd_HHmmss").format(new Date());
        return new File(mediaStorageDir.getPath() + File.separator +
                "IMG_"+ timeStamp + ".jpg");
    }
    */


    int TAKE_PHOTO_CODE = 0;
    public static int count = 0;


    @Override
    protected void onCreate(Bundle savedInstanceState)
    {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        final String dir = Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_PICTURES) + "/picFolder/";
        File newdir = new File(dir);
        newdir.mkdirs();

        Button capture = (Button) findViewById(R.id.btnCapture);
        capture.setOnClickListener(new View.OnClickListener() {
            public void onClick(View v) {

                // Here, the counter will be incremented each time, and the
                // picture taken by camera will be stored as 1.jpg,2.jpg
                // and likewise.
                count++;
                String file = dir+count+".jpg";
                File newfile = new File(file);
                try {
                    newfile.createNewFile();
                }
                catch (IOException e)
                {
                }

           //     Uri outputFileUri = Uri.fromFile(newfile);
                Uri outputFileUri = FileProvider.getUriForFile(MainActivity.this, BuildConfig.APPLICATION_ID, newfile);

                Intent cameraIntent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
                cameraIntent.putExtra(MediaStore.EXTRA_OUTPUT, outputFileUri);

                startActivityForResult(cameraIntent, TAKE_PHOTO_CODE);
            }
        });


    }

        @Override
    protected void onActivityResult(int requestCode, int resultCode, Intent data)
    {
        super.onActivityResult(requestCode, resultCode, data);

        if (requestCode == TAKE_PHOTO_CODE && resultCode == RESULT_OK) {
            Log.d("CameraDemo", "Pic saved");
        }
    }


    private void doOCR()
    {
     //   String temp = mTessOCR.getOCRResult(bitmap);

    }
}

Manifest:

<?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="com.m.textdetection">

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

    <application
        android:allowBackup="true"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:roundIcon="@mipmap/ic_launcher_round"
        android:supportsRtl="true"
        android:theme="@style/AppTheme">
        <activity android:name=".MainActivity">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>

        <provider
            android:name="android.support.v4.content.FileProvider"
            android:authorities="${applicationId}.my.package.name.provider"
            android:exported="false"
            android:grantUriPermissions="true"
            tools:replace="android:authorities">
            <meta-data
                android:name="android.support.FILE_PROVIDER_PATHS"
                android:resource="@xml/provider_paths"
                tools:replace="android:resource"/>
        </provider>

    </application>

</manifest>

build.gradle(app):

apply plugin: 'com.android.application'

android {
    compileSdkVersion 27
    buildToolsVersion "27.0.3"
    defaultConfig {
        applicationId "com.m.textdetection"
        minSdkVersion 21
        targetSdkVersion 27
        versionCode 1
        versionName "1.0"
        testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
    }
    buildTypes {
        release {
            minifyEnabled false
            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
        }
    }
}

dependencies {
    compile fileTree(dir: 'libs', include: ['*.jar'])
    androidTestCompile('com.android.support.test.espresso:espresso-core:2.2.2', {
        exclude group: 'com.android.support', module: 'support-annotations'
    })
    compile 'com.android.support:appcompat-v7:27.0.2'
    compile 'com.android.support.constraint:constraint-layout:1.0.2'
    testCompile 'junit:junit:4.12'

    compile 'com.rmtheis:tess-two:6.0.3'
    compile 'com.android.support:support-v4:27.0.2'

}

And this is the new error:

java.lang.NullPointerException: Attempt to invoke virtual method 'android.content.res.XmlResourceParser android.content.pm.ProviderInfo.loadXmlMetaData(android.content.pm.PackageManager, java.lang.String)' on a null object reference

Occurs in this line:

        Uri outputFileUri = FileProvider.getUriForFile(MainActivity.this, BuildConfig.APPLICATION_ID, newfile);

Edir2:

package com.m.textdetection;


import android.content.Context;
import android.content.res.AssetManager;
import android.graphics.Bitmap;
import android.os.Environment;
import android.util.Log;

import com.googlecode.tesseract.android.TessBaseAPI;

import java.io.File;
import java.io.FileOutputStream;
import java.io.InputStream;
import java.io.OutputStream;

public class MyTessOCR {
    private String datapath;
    private TessBaseAPI mTess;
    Context context;
    public MyTessOCR(Context context)
    {
        this.context = context;
        datapath = Environment.getExternalStorageDirectory() + "/ocrctz/";
        File dir = new File(datapath + "/tessdata/");
        File file = new File(datapath + "/tessdata/" + "eng.traineddata");
        if (!file.exists())
        {
            Log.d("mylog", "in file doesn't exist");
            dir.mkdirs();
            copyFile(context);
        }

        mTess = new TessBaseAPI();
        String language = "eng";
        mTess.init(datapath, language);
        //Auto only
        mTess.setPageSegMode(TessBaseAPI.PageSegMode.PSM_AUTO_ONLY);
    }

    public void stopRecognition() {
        mTess.stop();
    }

    public String getOCRResult(Bitmap bitmap)
    {
        mTess.setImage(bitmap);
        String result = mTess.getUTF8Text();
        return result;
    }

    public void onDestroy()
    {
        if (mTess != null)
            mTess.end();
    }

    private void copyFile(Context context)
    {
        AssetManager assetManager = context.getAssets();
        try
        {   InputStream in = assetManager.open("eng.traineddata");
            OutputStream out = new FileOutputStream(datapath + "/tessdata/" + "eng.traineddata");
            byte[] buffer = new byte[1024];
            int read = in.read(buffer);
            while (read != -1) {
                out.write(buffer, 0, read);
                read = in.read(buffer);            }
        } catch (Exception e)
        {
            Log.d("mylog", "couldn't copy with the following error : "+e.toString());
        }
    }
}

回答1:

If your targetSdkVersion >= 24, then we have to use FileProvider class to give access to the particular file or folder to make them accessible for other apps.

1) First Add a FileProvider tag in AndroidManifest.xml under tag as below:

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    ...
    <application
        ...
        <provider
        android:name="android.support.v4.content.FileProvider"
        android:authorities="${applicationId}.my.package.name.provider"
        android:exported="false"
        android:grantUriPermissions="true"
        tools:replace="android:authorities">
        <meta-data
            android:name="android.support.FILE_PROVIDER_PATHS"
            android:resource="@xml/provider_paths"
            tools:replace="android:resource"/>
    </provider> 
    </application>
</manifest>

2) Then create a provider_paths.xml file in res/xml folder. Folder may be needed to created if it doesn't exist.

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

3) Now edit your activity class file as below:

Uri outputFileUri = Uri.fromFile(newfile);

to

Uri outputFileUri = FileProvider.getUriForFile(MainActivity.this, BuildConfig.APPLICATION_ID, newfile);

UPDATE #1

Update your MainActivity.java with this:

import android.Manifest;
import android.content.Intent;
import android.content.pm.PackageManager;
import android.net.Uri;
import android.os.Build;
import android.os.Environment;
import android.provider.MediaStore;
import android.support.v4.app.ActivityCompat;
import android.support.v4.content.ContextCompat;
import android.support.v4.content.FileProvider;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.Button;
import android.widget.ImageView;
import android.widget.Toast;

import java.io.File;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;

public class MainActivity extends AppCompatActivity {

//    private MyTessOCR mTessOCR = new MyTessOCR(MainActivity.this);

    private Button takePictureButton;
    private ImageView imageView;





    int TAKE_PHOTO_CODE = 0;
    public static int count = 0;


    @Override
    protected void onCreate(Bundle savedInstanceState)
    {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        if (checkPermissions()){
            //  permissions  granted.

        }

        final String dir = Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_PICTURES) + "/picFolder/";
        File newdir = new File(dir);
        if (!newdir.exists()) {
            newdir.mkdir();
        }

        Button capture = (Button) findViewById(R.id.btnCapture);
        capture.setOnClickListener(new View.OnClickListener() {
            public void onClick(View v) {

                // Here, the counter will be incremented each time, and the
                // picture taken by camera will be stored as 1.jpg,2.jpg
                // and likewise.
                count++;
                String file = dir+count+".jpg";
                File newfile = new File(file);
                try {
                    newfile.createNewFile();
                }
                catch (IOException e)
                {
                }

                //     Uri outputFileUri = Uri.fromFile(newfile);
                Uri outputFileUri = FileProvider.getUriForFile(MainActivity.this, BuildConfig.APPLICATION_ID, newfile);

                Intent cameraIntent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
                cameraIntent.putExtra(MediaStore.EXTRA_OUTPUT, outputFileUri);

                startActivityForResult(cameraIntent, TAKE_PHOTO_CODE);
            }
        });


    }

    @Override
    protected void onActivityResult(int requestCode, int resultCode, Intent data)
    {
        super.onActivityResult(requestCode, resultCode, data);

        if (requestCode == TAKE_PHOTO_CODE && resultCode == RESULT_OK) {
            Log.d("CameraDemo", "Pic saved");
        }
    }





    public static final int MULTIPLE_PERMISSIONS = 10; // code you want.

    String[] permissions= new String[]{
            Manifest.permission.WRITE_EXTERNAL_STORAGE,
            Manifest.permission.CAMERA,
            Manifest.permission.ACCESS_COARSE_LOCATION,
            Manifest.permission.ACCESS_FINE_LOCATION};




    private  boolean checkPermissions() {
        int result;
        List<String> listPermissionsNeeded = new ArrayList<>();
        for (String p:permissions) {
            result = ContextCompat.checkSelfPermission(MainActivity.this,p);
            if (result != PackageManager.PERMISSION_GRANTED) {
                listPermissionsNeeded.add(p);
            }
        }
        if (!listPermissionsNeeded.isEmpty()) {
            ActivityCompat.requestPermissions(this, listPermissionsNeeded.toArray(new String[listPermissionsNeeded.size()]),MULTIPLE_PERMISSIONS );
            return false;
        }
        return true;
    }


    @Override
    public void onRequestPermissionsResult(int requestCode, String permissions[], int[] grantResults) {
        switch (requestCode) {
            case MULTIPLE_PERMISSIONS:{
                if(grantResults.length > 0 && grantResults[0] == PackageManager.PERMISSION_GRANTED){
                    // permissions granted.
                } else {
//                    Toast.makeText(this, "Go to settings and enable permissions", Toast.LENGTH_LONG)
//                            .show();
                    }
                    // permissions list of don't granted permission
                }
                return;
            }
        }



    private void doOCR()
    {
        //   String temp = mTessOCR.getOCRResult(bitmap);

    }
}

回答2:

Try this! Just paste the below code in activity onCreate()

StrictMode.VmPolicy.Builder builder = new StrictMode.VmPolicy.Builder();
StrictMode.setVmPolicy(builder.build());

It will ignore URI exposure