如何在Android应用中集成搜索功能

Question

I'm trying to create an application to display the call logs based on the call type (incoming calls, outgoing calls, or missing calls). In addition I'm trying to add search and delete functionalities so the user can search for the call (by number) and delete the call. The layout of the app is shown here:

The search functionality works if I hit the 'All' button to display all calls and search by number there, but upon going to other sections to search for a number, such as received or missed, the app crashes.

So far I have managed to run the logcat on Android Studio, and found that the main issue is in my main activity file. I have attached the logcat image here:

There seems to be issues with these pieces of code: my getCalls Method, afterTextChanged Method, and my updateCursor Method.

private Cursor getCalls(int type, String searchString) {
        Uri callUri = CallLog.Calls.CONTENT_URI;
        ContentResolver contentResolver = getContentResolver();

        String[] projection = new String[]{Calls._ID, Calls.NUMBER, Calls.DURATION, Calls.TYPE};

        String selection=null;
        String[] selectionArgs=null;

    if(type != 0){
        // filter type calls
        selection = Calls.TYPE + "=?";
        selectionArgs = new String[]{String.valueOf(type)};
    }

    if(!TextUtils.isEmpty(searchString)) {
        // has some search string
        if(TextUtils.isEmpty(selection)) {
            // all call types
            selection = Calls.NUMBER + " LIKE ?";
            selectionArgs = new String[]{"%"+searchString+"%"};
        } else {
            // some type of call and add search String
            selection = selection+" && " + Calls.NUMBER+" LIKE ?";
            selectionArgs = new String[]{selectionArgs[0],"'%"+searchString+"%'"};
        }
    }

    String order = Calls.DATE + " DESC ";

    //verify permissions to access the user's call log
    int permissionCheck = ContextCompat.checkSelfPermission(this, Manifest.permission.READ_CALL_LOG);

    if (permissionCheck == PackageManager.PERMISSION_GRANTED) {
        cursor = contentResolver.query(callUri,   // URI content provider
                projection,
                selection,
                selectionArgs,
                order);
    }
    return cursor;
}

@Override
public void afterTextChanged(Editable s) {
    updateCursor();
}

//updates the search
void updateCursor() {
    if (cursor != null && !cursor.isClosed()) {
        cursor.close();
        cursor = null;
    }
    cursor = getCalls(currentCallType, searchET.getText().toString());
    adapter.swapCursor(cursor);
}

Upon running the app, I expected to be able to go to different sections (for example, I go to the received call section) and search for a number, however upon going to the section and tapping on the search bar, the app crashes. I do not understand how there could be issues with these methods.

Answer 1

SQLException says the error is near the & symbol, so the error should be in this line:

selection = selection+" && " + Calls.NUMBER+" LIKE ?";

Let's replace it with this one, because 'AND' should be used in SQL instead of double &:

selection = selection+" AND " + Calls.NUMBER+" LIKE ?";