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day02Android数据存储.md

@@ -42,6 +42,215 @@ day02Android数据存储
         ```
     4. SQLiteDatabase    
         Store structured data in a private database.
+		Android平台中嵌入了一个关系型数据库SQLite，和其他数据库不同的是SQLite存储数据时不区分类型，例如一个字段声明为Integer类型，我们也可以将一个字符串存入，一个字段声明为布尔型，我们也可以存入浮点数。除非是主键被定义为Integer，这时只能存储64位整数创建数据库的表时可以不指定数据类型，例如：
+        `CREATE TABLE person(id INTEGER PRIMARY KEY AUTOINCREMENT, name VARCHAR(20))`
+        `CREATE TABLE person(id INTEGER PRIMARY KEY AUTOINCREMENT, name)`
+        SQLite支持大部分标准SQL语句，增删改查语句都是通用的，分页查询语句和MySQL相同
+        `SELECT * FROM person LIMIT 20 OFFSET 10`
+        `SELECT * FROM person LIMIT 10,20`
+		1. 继承SQLiteOpenHelper
+		    ```java
+			public class NoteSQLiteOpenHelper extends SQLiteOpenHelper {
+
+				private static final String TAG = "NoteSQLiteOpenHelper";
+				/**
+				 * context 上下文 name 数据库的名称 cursorfactory 游标工厂 一般设置null 默认游标工厂 version 数据库的版本
+				 * 版本号从1开始的
+				 * 
+				 * @param context
+				 */
+				public NoteSQLiteOpenHelper(Context context) {
+					super(context, "note.db", null, 1);
+				}
+
+				/**
+				 * oncreate 方法 会在数据库第一创建的时候的是被调用 适合做数据库表结构的初始化
+				 */
+				@Override
+				public void onCreate(SQLiteDatabase db) {
+					Log.i(TAG, "oncreate 方法被调用了...");
+					db.execSQL("create table account (id integer primary key autoincrement , name  varchar(20), money varchar(20) )");
+				}
+
+				@Override
+				public void onUpgrade(SQLiteDatabase db, int arg1, int arg2) {
+					Log.i(TAG,"onupdate 方法被调用了 ,在这个方法里面做更新数据库表结构的操作");
+					db.execSQL("DROP TABLE IF EXISTS " + account);
+					this.onCreate(db);
+				}
+			}
+			```
+			2. 获取
+			```java
+			public class NoteDao {
+				// 因为 任何一个操作都是需要 得到 NoteSQLiteOpenHelper helper
+				// 把他放在构造方法里面初始化
+				private NoteSQLiteOpenHelper helper;
+
+				public NoteDao(Context context) {
+					helper = new NoteSQLiteOpenHelper(context);
+				}
+
+				/**
+				 * 添加一条账目信息 到数据库
+				 * 
+				 * @param name
+				 *            花销的名称
+				 * @param money
+				 *            金额
+				 */
+				public void add(String name, float money) {
+					SQLiteDatabase db = helper.getWritableDatabase();
+					db.execSQL("insert into account (name,money) values (?,?)",
+							new Object[] { name, money });
+					// 记住 关闭.
+					db.close();
+				}
+
+				public void delete(int id) {
+					SQLiteDatabase db = helper.getWritableDatabase();
+					db.execSQL("delete from account where id=?", new Object[] { id });
+					db.close();
+				}
+
+				public void update(int id, float newmoney) {
+					SQLiteDatabase db = helper.getWritableDatabase();
+					db.execSQL("update account set money =? where id=?", new Object[] {
+							newmoney, id });
+					db.close();
+				}
+
+				/**
+				 * 返回数据库所有的条目
+				 * 
+				 * @return
+				 */
+				public List<NoteBean> findAll() {
+					// 得到可读的数据库
+					SQLiteDatabase db = helper.getReadableDatabase();
+					List<NoteBean> noteBeans = new ArrayList<NoteBean>();
+					// 获取到数据库查询的结果游标
+					Cursor cursor = db.rawQuery("select id,money,name from account ", null);
+					while (cursor.moveToNext()) {
+						int id = cursor.getInt(cursor.getColumnIndex("id"));
+						String name = cursor.getString(cursor.getColumnIndex("name"));
+						float money = cursor.getFloat(cursor.getColumnIndex("money"));
+						NoteBean bean = new NoteBean(id, money, name);
+						noteBeans.add(bean);
+						bean = null;
+					}
+
+					db.close();
+					return noteBeans;
+				}
+
+				/**
+				 * 模拟一个转账的操作. 使用数据库的事务
+				 * 
+				 * @throws Exception
+				 */
+				public void testTransaction() throws Exception {
+					// 得到可写的数据库
+					SQLiteDatabase db = helper.getWritableDatabase();
+					db.beginTransaction(); // 开始事务
+					try {
+						db.execSQL("update account set money = money - 5 where id=? ",
+								new String[] { "2" });
+						db.execSQL("update account set money = money + 5 where id=? ",
+								new String[] { "3" });
+						db.setTransactionSuccessful();
+					} catch (Exception e) {
+						// TODO: handle exception
+					} finally {
+						db.endTransaction();//关闭事务.
+						db.close();
+					}
+				}
+			}
+			```
+
+			```java
+			public class NoteDao2 {
+				private NoteSQLiteOpenHelper helper;
+
+				public NoteDao2(Context context) {
+					helper = new NoteSQLiteOpenHelper(context);
+				}
+
+				/**
+				 * 添加一条账目信息 到数据库
+				 * 
+				 * @param name
+				 *            花销的名称
+				 * @param money
+				 *            金额
+				 * 
+				 * @return true 插入成功 false 失败
+				 */
+				public boolean add(String name, float money) {
+					SQLiteDatabase db = helper.getWritableDatabase();
+					ContentValues values = new ContentValues();
+					values.put("name", name);
+					values.put("money", money);
+					long rawid = db.insert("account", null, values);
+					db.close();
+					if (rawid > 0) {
+						return true;
+					} else {
+						return false;
+					}
+				}
+
+				public boolean delete(int id) {
+					SQLiteDatabase db = helper.getWritableDatabase();
+					int result = db.delete("account", "id=?", new String[] { id + "" });
+					db.close();
+					if (result > 0) {
+						return true;
+					} else {
+						return false;
+					}
+				}
+
+				public boolean update(int id, float newmoney) {
+					SQLiteDatabase db = helper.getWritableDatabase();
+					ContentValues values = new ContentValues();
+					values.put("id", id);
+					values.put("money", newmoney);
+					int result = db.update("account", values, "id=?", new String[] { id
+							+ "" });
+					db.close();
+					if (result > 0) {
+						return true;
+					} else {
+						return false;
+					}
+				}
+
+				/**
+				 * 返回数据库所有的条目
+				 * 
+				 * @return
+				 */
+				public List<NoteBean> findAll() {
+					// 得到可读的数据库
+					SQLiteDatabase db = helper.getReadableDatabase();
+					List<NoteBean> noteBeans = new ArrayList<NoteBean>();
+					Cursor cursor = db.query("account", new String[] { "id", "name",
+							"money" }, null, null, null, null, null);
+					while (cursor.moveToNext()) {
+						int id = cursor.getInt(cursor.getColumnIndex("id"));
+						String name = cursor.getString(cursor.getColumnIndex("name"));
+						float money = cursor.getFloat(cursor.getColumnIndex("money"));
+						NoteBean bean = new NoteBean(id, money, name);
+						noteBeans.add(bean);
+						bean = null;
+					}
+					db.close();
+					return noteBeans;
+				}
+			}
+			```
     5. Network    
         Store data on the web with your own network server.
 

day03内容提供者.md

@@ -0,0 +1,152 @@
+day02Android数据存储
+===
+
+1. ContentProvider
+    一个可以在不同应用程序间共享数据的组件，相当于一个中间人，一边把数据暴露给这个中间人，另一边是别的应用通过这个中间人获取相应的数据。
+    1. 继承ContentProvider,并实现相应的方法，由于是一个中间人，我们要检查这个中间人是不是冒牌的，所以就要去验证URI
+	```java
+	public class NoteInfoProvider extends ContentProvider {
+
+		private static final int QUERY = 1;
+		private static final int INSERT = 2;
+		private static final int DELETE = 3;
+		private static final int UPDATE = 4;
+
+		// 参数code 代表如果uri不匹配的返回值
+		// 在当前应用程序的内部 声明一个路径的检查者
+		private static UriMatcher matcher = new UriMatcher(UriMatcher.NO_MATCH);
+		private SQLiteDatabase db;
+
+		static {
+			// 建立一个匹配规则
+			// 1.如果发现一个路径 com.itheima.note.noteprovider/query 查询的操作
+			matcher.addURI("com.itheima.note.noteprovider", "query", QUERY);
+			matcher.addURI("com.itheima.note.noteprovider", "insert", INSERT);
+			matcher.addURI("com.itheima.note.noteprovider", "delete", DELETE);
+			matcher.addURI("com.itheima.note.noteprovider", "update", UPDATE);
+		}
+
+		@Override
+		public boolean onCreate() {
+			NoteSQLiteOpenHelper helper = new NoteSQLiteOpenHelper(getContext());
+			db = helper.getWritableDatabase();
+			return false;
+		}
+
+		/**
+		 * 内容提供者暴露的查询的方法.
+		 */
+		@Override
+		public Cursor query(Uri uri, String[] projection, String selection,
+				String[] selectionArgs, String sortOrder) {
+			// 1.重要的事情 ,检查 uri的路径.
+			int code = matcher.match(uri);
+			if (code == QUERY) {
+				// 查询处理
+				NoteSQLiteOpenHelper helper = new NoteSQLiteOpenHelper(getContext());
+				SQLiteDatabase db = helper.getReadableDatabase();
+				Cursor cursor = db.rawQuery("select * from account", null);
+				return cursor;
+			} else {
+				throw new IllegalArgumentException("路径不能被识别,我不认识你...");
+			}
+		}
+
+		@Override
+		public String getType(Uri uri) {
+			int code = matcher.match(uri);
+			if (code == QUERY) {
+				//返回一条数据
+				return "vnd.android.cursor.item/note";
+				//返回多条数据
+				//return "vnd.android.cursor.dir/note"
+			}
+		
+			
+			return null;
+		}
+
+		@Override
+		public Uri insert(Uri uri, ContentValues values) {
+			int code = matcher.match(uri);
+			if (code == INSERT) {
+				db.insert("account", null, values);
+			} else {
+				throw new IllegalArgumentException("路径不能被识别,我不认识你...");
+			}
+
+			return null;
+		}
+
+		@Override
+		public int delete(Uri uri, String selection, String[] selectionArgs) {
+			int code = matcher.match(uri);
+			if (code == DELETE) {
+				db.delete("account", selection, selectionArgs);
+			} else {
+				throw new IllegalArgumentException("路径不能被识别,我不认识你...");
+			}
+
+			return 0;
+		}
+
+		@Override
+		public int update(Uri uri, ContentValues values, String selection,
+				String[] selectionArgs) {
+			int code = matcher.match(uri);
+			if (code == UPDATE) {
+				db.update("account", values, selection, selectionArgs);
+			} else {
+				throw new IllegalArgumentException("路径不能被识别,我不认识你...");
+			}
+			return 0;
+		}
+	}
+	```
+	2. 在清单文件中进行注册，并且指定其authorities
+	```xml
+	<provider
+		android:name="com.itheima.note.provider.NoteInfoProvider"
+		android:authorities="com.itheima.note.noteprovider" >
+	```
+	3. 在另外一个应用程序中使用内容提供者获取数据,使用ContentResolver去操作ContentProvider,ContentResolver用于管理ContentProvider实例，并且可实现找到指定的Contentprovider并获取到Contentprovider的数据。
+	```java
+	public void query(View view){
+		//得到内容提供者的解析器  中间人
+		ContentResolver resolver = getContentResolver();
+		Uri uri = Uri.parse("content://com.itheima.note.noteprovider/queryaa");
+		Cursor cursor = resolver.query(uri, null, null, null, null);
+		while(cursor.moveToNext()){
+			String name = cursor.getString(cursor.getColumnIndex("name"));
+			int id = cursor.getInt(cursor.getColumnIndex("id"));
+			float money = cursor.getFloat(cursor.getColumnIndex("money"));
+			System.out.println("id="+id+",name="+name+",money="+money);
+		}
+		cursor.close();
+	}
+	public void insert(View view){
+		ContentResolver resolver = getContentResolver();
+		Uri uri = Uri.parse("content://com.itheima.note.noteprovider/insert");
+		ContentValues values = new ContentValues();
+		values.put("name", "买洗头膏");
+		values.put("money", 22.58f);
+		resolver.insert(uri, values);
+	}
+	public void update(View view){
+		ContentResolver resolver = getContentResolver();
+		Uri uri = Uri.parse("content://com.itheima.note.noteprovider/update");
+		ContentValues values = new ContentValues();
+		values.put("name", "买洗头膏");
+		values.put("money", 42.58f);
+		resolver.update(uri, values, "name=?", new String[]{"买洗头膏"});
+	}
+	public void delete(View view){
+		ContentResolver resolver = getContentResolver();
+		Uri uri = Uri.parse("content://com.itheima.note.noteprovider/delete");
+		resolver.delete(uri, "name=?", new String[]{"买洗头膏"});
+	}
+	```
+---
+
+- 邮箱 ：[email protected]  
+- Good Luck!