第一行代码 第7章 内容提供器 --实现跨程序数据共享

DatabaseTest.apk源码如下:

MainActivity.java

public class MainActivity extends AppCompatActivity implements View.OnClickListener {    private MyDatabaseHelper myDatabaseHelper;    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_main);        myDatabaseHelper = new MyDatabaseHelper(this, "BookStore.db", null, 1);        Button createDatabase = (Button)findViewById(R.id.create_database);        createDatabase.setOnClickListener(this);        Button addData = (Button)findViewById(R.id.add_data);        addData.setOnClickListener(this);        Button updateData = (Button)findViewById(R.id.update_data);        updateData.setOnClickListener(this);        Button deleteData = (Button)findViewById(R.id.delete_data);        deleteData.setOnClickListener(this);        Button queryData = (Button)findViewById(R.id.query_data);        queryData.setOnClickListener(this);    }    @Override    public void onClick(View view) {        SQLiteDatabase db = myDatabaseHelper.getReadableDatabase();        ContentValues values = new ContentValues();        switch (view.getId()){            case R.id.create_database:                //myDatabaseHelper.getReadableDatabase();                break;            case R.id.add_data:                values.put("author", "admin");                values.put("book_name", "Android");                values.put("pages", 800);                values.put("price", 68.4);                db.insert("Book", null, values);                values.clear();                values.put("author", "sky");                values.put("book_name", "Iphone");                values.put("pages", 1000);                values.put("price", 78.2);                db.insert("Book", null, values);                break;            case R.id.update_data:                values.put("price", 12.02);                db.update("Book", values, "book_name=?", new String[]{"Android"});                break;            case R.id.delete_data:                db.delete("Book", "book_name=?", new String[]{"Android"});                break;            case R.id.query_data:                int count = 0;                Cursor cursor = db.query("Book", null, null, null, null, null,null);                if(cursor.moveToFirst()){                    do{                        String author = cursor.getString(cursor.getColumnIndex("author"));                        Toast.makeText(this,author+":"+count,Toast.LENGTH_SHORT).show();                        count++;                    }while (cursor.moveToNext());                }                cursor.close();                break;            default:                break;        }    }}

MyDatabaseHelper.java

public class MyDatabaseHelper extends SQLiteOpenHelper {    private Context context;    public static final String CREATE_BOOK = "create table Book (" +            "id integer primary key autoincrement," +            "author text," +            "price real," +            "pages integer," +            "book_name text)";    public static final String CREATE_CATEGORY = "create table Category (" +            "id integer primary key autoincrement, " +            "category_name text, " +            "category_code integer)" ;    public MyDatabaseHelper(Context context, String name, SQLiteDatabase.CursorFactory factory, int version) {        super(context, name, factory, version);        this.context = context;    }    @Override    public void onCreate(SQLiteDatabase sqLiteDatabase) {        sqLiteDatabase.execSQL(CREATE_BOOK);    }    @Override    public void onUpgrade(SQLiteDatabase sqLiteDatabase, int i, int i1) {        sqLiteDatabase.execSQL(CREATE_CATEGORY);    }}

MyContentProvider.java

public class MyContentProvider extends ContentProvider {    public static final int BOOK_DIR = 0;    public static final int BOOK_ITEM = 1;    public static final int CATEGORY_DIR = 2;    public static final int CATEGORY_ITEM = 3;    public static final String AUTHORITY = "com.sky.databasetest.provider";    private static UriMatcher uriMatcher;    private MyDatabaseHelper dbHelper;    static {        uriMatcher = new UriMatcher(UriMatcher.NO_MATCH);        uriMatcher.addURI(AUTHORITY, "Book", BOOK_DIR);        uriMatcher.addURI(AUTHORITY, "Book/#", BOOK_ITEM);        uriMatcher.addURI(AUTHORITY, "Category", CATEGORY_DIR);        uriMatcher.addURI(AUTHORITY, "Category/#", CATEGORY_ITEM);    }    public MyContentProvider() {    }    @Override    public boolean onCreate() {        dbHelper = new MyDatabaseHelper(getContext(), "BookStore.db", null, 2);        return true;    }    @Override    public String getType(Uri uri) {        String type = null;        switch (uriMatcher.match(uri)){            case BOOK_DIR:                type = "vnd.android.cursor.dir/vnd.com.sky.databasetest.provider.Book";                break;            case BOOK_ITEM:                type = "vnd.android.cursor.item/vnd.com.sky.databasetest.provider.Book";                break;            case CATEGORY_DIR:                type = "vnd.android.cursor.dir/vnd.com.sky.databasetest.provider.Category";                break;            case CATEGORY_ITEM:                type = "vnd.android.cursor.item/vnd.com.sky.databasetest.provider.Category";                break;            default:                break;        }        return type;    }    @Override    public Uri insert(Uri uri, ContentValues values) {        SQLiteDatabase db = dbHelper.getReadableDatabase();        Uri uriRet=null;        switch (uriMatcher.match(uri)){            case BOOK_DIR:            case BOOK_ITEM:                long newBookId = db.insert("Book", null, values);                uriRet = Uri.parse("content://" + AUTHORITY + "/Book/"+newBookId);                break;            case CATEGORY_DIR:            case CATEGORY_ITEM:                long newCategoryId = db.insert("Category", null, values);                uriRet = Uri.parse("content://" + AUTHORITY + "/Category/"+newCategoryId);                break;            default:break;        }        return uriRet;    }    @Override    public Cursor query(Uri uri, String[] projection, String selection,                        String[] selectionArgs, String sortOrder) {        SQLiteDatabase db = dbHelper.getReadableDatabase();        Cursor cursor = null;        switch (uriMatcher.match(uri)){            case BOOK_DIR:                cursor = db.query("Book", projection, selection, selectionArgs, null, null, sortOrder);                break;            case BOOK_ITEM:                String bookId = uri.getPathSegments().get(1);                cursor = db.query("Book", projection, "id=?", new String[]{bookId}, null, null, sortOrder);                break;            case CATEGORY_DIR:                cursor = db.query("Category", projection, selection, selectionArgs, null, null, sortOrder);                break;            case CATEGORY_ITEM:                String categoryId = uri.getPathSegments().get(1);                cursor = db.query("Category", projection, "id=?", new String[]{categoryId}, null, null, sortOrder);                break;            default:break;        }        return cursor;    }    @Override    public int update(Uri uri, ContentValues values, String selection,                      String[] selectionArgs) {        SQLiteDatabase db = dbHelper.getReadableDatabase();        int updateRows = 0;        switch (uriMatcher.match(uri)){            case BOOK_DIR:                updateRows = db.update("Book", values, selection, selectionArgs);                break;            case BOOK_ITEM:                String bookId = uri.getPathSegments().get(1);                updateRows = db.update("Book", values, "id=?", new String[]{bookId});                break;            case CATEGORY_DIR:                updateRows = db.update("Category", values, selection, selectionArgs);                break;            case CATEGORY_ITEM:                String categoryId = uri.getPathSegments().get(1);                updateRows = db.update("Category", values, "id=?", new String[]{categoryId});                break;            default:break;        }        return updateRows;    }    @Override    public int delete(Uri uri, String selection, String[] selectionArgs) {        SQLiteDatabase db = dbHelper.getReadableDatabase();        int deleteRows = 0;        switch (uriMatcher.match(uri)){            case BOOK_DIR:                deleteRows = db.delete("Book", selection, selectionArgs);                break;            case BOOK_ITEM:                String bookId = uri.getPathSegments().get(1);                deleteRows = db.delete("Book", "id=?", new String[]{bookId});                break;            case CATEGORY_DIR:                deleteRows = db.delete("Category", selection, selectionArgs);                break;            case CATEGORY_ITEM:                String categoryId = uri.getPathSegments().get(1);                deleteRows = db.delete("Category", "id=?", new String[]{categoryId});                break;            default:break;        }        return deleteRows;    }}

AndroidManifest.xml

<?xml version="1.0" encoding="utf-8"?><manifest xmlns:android="http://schemas.android.com/apk/res/android"    package="com.sky.databasetest">    <application        android:allowBackup="true"        android:icon="@mipmap/ic_launcher"        android:label="@string/app_name"        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=".MyContentProvider"            android:authorities="com.sky.databasetest.provider"            android:enabled="true"            android:exported="true">        </provider>    </application></manifest>

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ProviderTest.apk源码如下：
MainActivity.java

public class MainActivity extends AppCompatActivity implements View.OnClickListener {    public static final String AUTHORITY = "com.sky.databasetest.provider";    private String newId;    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_main);        Button btnAddData = (Button)findViewById(R.id.btnAddData);        Button btnQueryData = (Button)findViewById(R.id.btnQueryData);        Button btnUpdateData = (Button)findViewById(R.id.btnUpdateData);        Button btnDeleteData = (Button)findViewById(R.id.btnDeleteData);        btnAddData.setOnClickListener(this);        btnQueryData.setOnClickListener(this);        btnUpdateData.setOnClickListener(this);        btnDeleteData.setOnClickListener(this);    }    @Override    public void onClick(View view) {        switch (view.getId()){            case R.id.btnAddData: {                Uri uri = Uri.parse("content://"+ AUTHORITY + "/Book");                ContentValues values = new ContentValues();                values.put("book_name", "adfsaffsf");                values.put("author", "aha");                values.put("price", "45.3");                values.put("pages", "120");                Uri newUri = getContentResolver().insert(uri, values);                newId = newUri.getPathSegments().get(1);            }                break;            case R.id.btnQueryData: {                Uri uri = Uri.parse("content://"+ AUTHORITY+"/Book");                Cursor cursor = getContentResolver().query(uri, null, null, null, null);                if(cursor!=null){                    while (cursor.moveToNext()){                        String name = cursor.getString(cursor.getColumnIndex("book_name"));                        String author = cursor.getString(cursor.getColumnIndex("author"));                        int page = cursor.getInt(cursor.getColumnIndex("pages"));                        double price = cursor.getDouble(cursor.getColumnIndex("price"));                        Log.d("MainActivity", "book name is :" + name);                        Log.d("MainActivity", "book author is :" + author);                        Log.d("MainActivity", "book page is :" + page);                        Log.d("MainActivity", "book price is :" + price);                    }                    cursor.close();                }            }                break;            case R.id.btnUpdateData:{                Uri uri = Uri.parse("content://"+ AUTHORITY + "/Book/" + newId);                ContentValues values = new ContentValues();                values.put("price", "22.6");                getContentResolver().update(uri, values, null, null);            }                break;            case R.id.btnDeleteData:{                Uri uri = Uri.parse("content://"+ AUTHORITY + "/Book/" + newId);                getContentResolver().delete(uri, null, null);            }                break;            default:                break;        }    }}

AndroidManifest.xml

<?xml version="1.0" encoding="utf-8"?><manifest xmlns:android="http://schemas.android.com/apk/res/android"    package="com.sky.providertest">    <application        android:allowBackup="true"        android:icon="@mipmap/ic_launcher"        android:label="@string/app_name"        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>    </application></manifest>