将联系人备份到 .VCF 文件不起作用

Question

因为我是 Java 新手，所以我自己编写了这段代码，其中一些部分是从其他来源学习的。我想将所有联系人信息备份到主存储或 sdcard 中的 .vcf 文件中（没关系），最后将它们取回。但在这段代码中你只能看到备份部分：

public class MainActivity extends Activity
{
    Cursor cursor;
    ArrayList<String> vCard ;
    String vfile;

    @Override
    public void onCreate(Bundle savedInstanceState)
    {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        vfile = "Contacts" + "_" + System.currentTimeMillis()+".vcf";
        getVcardString();

    }
    private void getVcardString() {
        vCard = new ArrayList<String>();
        cursor = getContentResolver().query(ContactsContract.CommonDataKinds.Phone.CONTENT_URI, null, null, null, null);
        if(cursor!=null&&cursor.getCount()>0)
        {
            cursor.moveToFirst();
            for(int i =0;i<cursor.getCount();i++)
            {

                get(cursor);
                Log.d("TAG", "Contact "+(i+1)+"VcF String is"+vCard.get(i));
                cursor.moveToNext();
            }

        }
        else
        {
            Log.d("TAG", "No Contacts in Your Phone");
        }

    }

    public void get(Cursor cursor)
    {

        String lookupKey = cursor.getString(cursor.getColumnIndex(ContactsContract.Contacts.LOOKUP_KEY));
        Uri uri = Uri.withAppendedPath(ContactsContract.Contacts.CONTENT_VCARD_URI, lookupKey);
        AssetFileDescriptor fd;
        try {
            fd = this.getContentResolver().openAssetFileDescriptor(uri, "r");

            FileInputStream fis = fd.createInputStream();
            byte[] buf = new byte[(int) fd.getDeclaredLength()];
            fis.read(buf);
            String vcardstring= new String(buf);
            vCard.add(vcardstring);

            String storage_path = Environment.getRootDirectory().toString() + File.separator + vfile;
            FileOutputStream mFileOutputStream = new FileOutputStream(storage_path, false);
            mFileOutputStream.write(vcardstring.toString().getBytes());

        } catch (Exception e1)
        {
            e1.printStackTrace();
        }
    }

}

问题是代码不起作用并且没有出现异常或任何错误。我搜索了根目录和所有文件夹，但没有 .vcf 文件。我的权限是：<uses-permission android:name="android.permission.READ_CONTACTS" /> <uses-permission android:name="android.permission.WRITE_CONTACTS" /> 我在 API 17 和 24 上运行了它。知道为什么它不起作用吗？

Answer 1

public void shoro(View v) throws IOException {

    Toast.makeText(this,"ok2",Toast.LENGTH_SHORT).show();
    vfile = "Contacts" + "_" + System.currentTimeMillis()+".vcf";
    vCard = new ArrayList<String>();
    cursor = getContentResolver().query(ContactsContract.CommonDataKinds.Phone.CONTENT_URI, null, null, null, null);
    if(cursor!=null&&cursor.getCount()>0)
    {
        Toast.makeText(this,"ok3",Toast.LENGTH_SHORT).show();
        cursor.moveToFirst();
        for(int i =0;i<cursor.getCount();i++)
        {

            get(cursor);
            Log.d("TAG", "Contact "+(i+1)+"VcF String is"+vCard.get(i));
            cursor.moveToNext();
        }

    }
    else
    {
        Log.d("TAG", "No Contacts in Your Phone");
    }

}

public void get(Cursor cursor) throws IOException {
    Toast.makeText(this,"ok4",Toast.LENGTH_SHORT).show();

    String lookupKey = cursor.getString(cursor.getColumnIndex(ContactsContract.Contacts.LOOKUP_KEY));
    Uri uri = Uri.withAppendedPath(ContactsContract.Contacts.CONTENT_VCARD_URI, lookupKey);
    AssetFileDescriptor fd;

    fd = this.getContentResolver().openAssetFileDescriptor(uri, "r");

    FileInputStream fis = fd.createInputStream();
    byte[] buf = new byte[(int) fd.getDeclaredLength()];
    fis.read(buf);
    String vcardstring= new String(buf);
    vCard.add(vcardstring);

    String storage_path = Environment.getDataDirectory().toString() + File.separator + vfile;
    FileOutputStream mFileOutputStream = new FileOutputStream(storage_path, false);
    mFileOutputStream.write(vcardstring.toString().getBytes());


}

首先看一下那些 Toast，我把它们放出来看看应用程序运行到哪一行。奇怪的是，我第一次问这些问题时忘记将电话号码添加到我的联系人中（我有 3 个联系人进行测试），当我运行应用程序时（当我没有添加号码时）应用程序继续运行没有任何错误，但没有不行（我们之前的谈话是关于这个的，我的错：D）。然后，当我检查 Toast 时，我发现该应用程序永远不会达到“ok3” Toast。之后，当我将号码添加到联系人时，现在该应用程序甚至无法运行。当我按下按钮时，它崩溃并关闭。我将运行中的行放在下面链接（API 17）中的记事本中：

https://ufile.io/i3gu4

我也在 API 24 和 21 上对此进行了测试，但同样的问题。可能是什么问题？

Answer 2

public void terp(View v) 抛出 IOException { Toast.makeText(this,"ok",Toast.LENGTH_SHORT).show();

    if (ActivityCompat.checkSelfPermission(this, Manifest.permission.WRITE_CONTACTS) != PackageManager.PERMISSION_GRANTED) {
        ActivityCompat.requestPermissions(this,new String[]{ Manifest.permission.READ_CONTACTS, Manifest.permission.WRITE_CONTACTS }, 12345);
    } else {
        // WE ALREADY HAVE PERMISSION, RUN THE MAIN FUNCTION
        shoro();
    }

}


public void onRequestPermissionsResult(int requestCode, String[] permissions, int[] grantResults) {
    Toast.makeText(this,"salam1",Toast.LENGTH_SHORT).show();
    if ((requestCode == 12345) && (grantResults[0] == PackageManager.PERMISSION_GRANTED)) {
        Toast.makeText(this,"salam2",Toast.LENGTH_SHORT).show();
        // WE GOT THE PERMISSION, RUN THE MAIN FUNCTION
        try {
            shoro();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

shoro() 是主函数。

Answer 3

Android 不允许您在 Environment.getDataDirectoy() 中创建文件。这指向供系统使用的 /data 文件夹。如果你想使用内部存储，你可以使用 /data/data/your_app_package 存储。要访问它，您只需更改 1 行代码 -

String storage_path = getFilesDir().getAbsolutePath() + File.separator + vfile;

要验证您的文件是否已创建，您可以执行以下步骤

1. 从工具打开 Android 设备监视器 -> Android -> Android 设备监视器
2. 在左侧的“设备”选项卡中选择模拟器。
3. 选择右侧部分的文件资源管理器选项卡
4. 转到 /data/data/YOUR_PACKAGE_NAME 文件夹。在里面，您将看到创建文件的文件部分

如果您想使用外部存储，请使用 Environment.getExternalStorageDirectory() 方法。

要了解 Android 设备中的不同路径，请查看here

更新 1 讨论后这里是更新的代码。有多个问题 - 1）我们需要接受多个权限并满足 API >= 23 的所有权限 2) AssetFileDescriptor 将 API > = 24 的长度设为 -1 因此代码被破坏了。

所以在 2 个地方改变 - 改变你的 get 方法 -

 public void get(Cursor cursor) throws IOException {
    Toast.makeText(this,"ok4",Toast.LENGTH_SHORT).show();

    String lookupKey = cursor.getString(cursor.getColumnIndex(ContactsContract.Contacts.LOOKUP_KEY));
    Uri vCardUri = Uri.withAppendedPath(ContactsContract.Contacts.CONTENT_VCARD_URI, lookupKey);
    AssetFileDescriptor assetFileDescriptor;
    String vcardstring="";
    if (Build.VERSION.SDK_INT >= 24) {

        FileInputStream inputStream=null;
        byte[] buffer = new byte[4096];
        ByteArrayOutputStream ous = null;
        try {
            assetFileDescriptor = this.getContentResolver().openAssetFileDescriptor(vCardUri, "r");

            if (assetFileDescriptor != null) {
                ous = new ByteArrayOutputStream();
                int read = 0;
                inputStream = assetFileDescriptor.createInputStream();
                while ((read = inputStream.read(buffer)) != -1) {
                    ous.write(buffer, 0, read);
                }
            }
        } catch (FileNotFoundException e) {
            Log.e(TAG, "Vcard for the contact " + lookupKey + " not found", e);
        } catch (IOException e) {
            Log.e(TAG, "Problem creating stream from the assetFileDescriptor.", e);
        }finally {
            try {
                if (ous != null)
                    ous.close();
            } catch (IOException e) {
            }

            try {
                if (inputStream != null)
                    inputStream.close();
            } catch (IOException e) {
            }
        }
        vcardstring= new String(ous.toByteArray());

    }else{

        assetFileDescriptor = this.getContentResolver().openAssetFileDescriptor(vCardUri, "r");

        FileInputStream fis = assetFileDescriptor.createInputStream();
        byte[] buf = new byte[(int) assetFileDescriptor.getDeclaredLength()];
        fis.read(buf);
        vcardstring= new String(buf);

    }


    vCard.add(vcardstring);
    Log.i("File Kapil", "path "+getFilesDir().getAbsolutePath().toString());
    String storage_path = getFilesDir().getAbsolutePath() + File.separator + vfile;
    FileOutputStream mFileOutputStream = new FileOutputStream(storage_path, false);
    mFileOutputStream.write(vcardstring.toString().getBytes());

}

对于请求权限更改 -

public  boolean isStoragePermissionGranted() {
    if (Build.VERSION.SDK_INT >= 23) {

        if (checkSelfPermission(android.Manifest.permission.WRITE_EXTERNAL_STORAGE)
                == PackageManager.PERMISSION_GRANTED && checkSelfPermission(Manifest.permission.WRITE_CONTACTS)
                == PackageManager.PERMISSION_GRANTED && checkSelfPermission(Manifest.permission.READ_CONTACTS)
                == PackageManager.PERMISSION_GRANTED) {
            Log.v(TAG,"Permission is granted");
            return true;
        } else {

            Log.v(TAG,"Permission is revoked");
            ActivityCompat.requestPermissions(this, new String[]{Manifest.permission.WRITE_EXTERNAL_STORAGE, Manifest.permission.WRITE_CONTACTS, Manifest.permission.READ_CONTACTS}, 1);
            return false;
        }
    }
    else { //permission is automatically granted on sdk<23 upon installation
        Log.v(TAG,"Permission is granted");
        return true;
    }
}

@Override
public void onRequestPermissionsResult(int requestCode, String permissions[], int[] grantResults) {
    switch (requestCode) {
        case 0:
            boolean isPerpermissionForAllGranted = false;
            if (grantResults.length > 0 && permissions.length==grantResults.length) {
                for (int i = 0; i < permissions.length; i++){
                    if (grantResults[i] == PackageManager.PERMISSION_GRANTED){
                        isPerpermissionForAllGranted=true;
                    }else{
                        isPerpermissionForAllGranted=false;
                    }
                }

                Log.e("value", "Permission Granted, Now you can use local drive .");
            } else {
                isPerpermissionForAllGranted=true;
                Log.e("value", "Permission Denied, You cannot use local drive .");
            }
            if(isPerpermissionForAllGranted){
                shoro();
            }
            break;
    }
}

在你的 Shoro 方法中稍微修改一下代码——

 public void shoro(){
   boolean isPermissionGiven =  isStoragePermissionGranted();
   Toast.makeText(this,"ok2",Toast.LENGTH_SHORT).show();
    if (isPermissionGiven){
        // Do stuff
    }
 }

完整代码可见-Here