在Content Provider

Question

我一直在尝试在我的应用中添加内容提供商，但它显示的网址未找到。我尝试在Android清单文件中添加标记，并将权限地址设置为我的包地址，但结果仍然相同。有数据库和合同java文件也有，但问题仅在于FCMprovider.java。请帮助

错误：

java.lang.RuntimeException: Unable to start activity ComponentInfo{fcm.bio.fcm/fcm.bio.MainActivity}: java.lang.IllegalArgumentException: Unknown URL content://fcm.bio.ayushsharma.fcm.provider.provider/messages

FCMprovider.java

@ContentProvider(
    authority = FCMprovider.AUTHORITY,
    database = FCMdatabase.class
)

public class FCMprovider {
public static final String 
AUTHORITY="fcm.bio.ayushsharma.fcm.provider.provider";

@TableEndpoint(table = FCMdatabase.FCM_MESSAGES)
public static class FCMmessages{
    @ContentUri(
            path = "messages",
            type="vnd.android.cursor.dir/message",
            defaultSort = FCMcontract.COLUMN_DATE+"DESC")
    public static final Uri CONTENT_URI=Uri.parse("content://"+ AUTHORITY + "/messages");
}

}

AndroidManifest.java

 <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">

    <provider
        android:authorities="com.bio.ayushsharma.fcm.provider.provider"
        android:name=".provider.generated.FCMprovider"
        android:exported="false"/>
    <activity android:name=".MainActivity">
        <intent-filter>
            <action android:name="android.intent.action.MAIN" />

            <category android:name="android.intent.category.LAUNCHER" />
        </intent-filter>
    </activity>
    <activity android:name=".following.followingPreferenceActivity">
        <meta-data
            android:name="android.support.PARENT_ACTIVITY"
            android:value=".MainActivity"/>
    </activity>
</application>

mainActivity.java

public class MainActivity extends AppCompatActivity implements
    LoaderManager.LoaderCallbacks<Cursor> {

private static String LOG_TAG = MainActivity.class.getSimpleName();
private static final int LOADER_ID_MESSAGES = 0;

RecyclerView mRecyclerView;
LinearLayoutManager mLayoutManager;
SquawkAdapter mAdapter;

static final String[] MESSAGES_PROJECTION = {
        SquawkContract.COLUMN_AUTHOR,
        SquawkContract.COLUMN_MESSAGE,
        SquawkContract.COLUMN_DATE,
        SquawkContract.COLUMN_AUTHOR_KEY
};

static final int COL_NUM_AUTHOR = 0;
static final int COL_NUM_MESSAGE = 1;
static final int COL_NUM_DATE = 2;
static final int COL_NUM_AUTHOR_KEY = 3;


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

    mRecyclerView = (RecyclerView) findViewById(R.id.squawks_recycler_view);

    // Use this setting to improve performance if you know that changes
    // in content do not change the layout size of the RecyclerView
    mRecyclerView.setHasFixedSize(true);

    // Use a linear layout manager
    mLayoutManager = new LinearLayoutManager(this);
    mRecyclerView.setLayoutManager(mLayoutManager);

    // Add dividers
    DividerItemDecoration dividerItemDecoration = new DividerItemDecoration(
            mRecyclerView.getContext(),
            mLayoutManager.getOrientation());
    mRecyclerView.addItemDecoration(dividerItemDecoration);

    // Specify an adapter
    mAdapter = new SquawkAdapter();
    mRecyclerView.setAdapter(mAdapter);

    // Start the loader
    getSupportLoaderManager().initLoader(LOADER_ID_MESSAGES, null, this);

}

@Override
public boolean onCreateOptionsMenu(Menu menu) {
    MenuInflater inflater = getMenuInflater();
    inflater.inflate(R.menu.main_menu, menu);
    return true;
}

@Override
public boolean onOptionsItemSelected(MenuItem item) {
    int id = item.getItemId();
    if (id == R.id.action_following_preferences) {
        // Opens the following activity when the menu icon is pressed
        Intent startFollowingActivity = new Intent(this, FollowingPreferenceActivity.class);
        startActivity(startFollowingActivity);
        return true;
    }
    return super.onOptionsItemSelected(item);
}


/**
 * Loader callbacks
 */

@Override
public Loader<Cursor> onCreateLoader(int id, Bundle args) {
    // This method generates a selection off of only the current followers
    String selection = SquawkContract.createSelectionForCurrentFollowers(
            PreferenceManager.getDefaultSharedPreferences(this));
    Log.d(LOG_TAG, "Selection is " + selection);
    return new CursorLoader(this, SquawkProvider.SquawkMessages.CONTENT_URI,
            MESSAGES_PROJECTION, selection, null, SquawkContract.COLUMN_DATE + " DESC");
}

@Override
public void onLoadFinished(Loader<Cursor> loader, Cursor data) {
    mAdapter.swapCursor(data);
}

@Override
public void onLoaderReset(Loader<Cursor> loader) {
    mAdapter.swapCursor(null);
}
}

Answer 1

android:authorities="com.bio.ayushsharma.fcm.provider.provider"

这从com.

开始

AUTHORITY="fcm.bio.ayushsharma.fcm.provider.provider";

这从fcm开始。

这些不一样，它们必须相同。所以，改变其中一个。