forked from CharonChui/AndroidNote
-
Notifications
You must be signed in to change notification settings - Fork 0
Commit
This commit does not belong to any branch on this repository, and may belong to a fork outside of the repository.
Merge branch 'master' of https://github.com/CharonChui/AndroidNote.git
- Loading branch information
Showing
5 changed files
with
466 additions
and
67 deletions.
There are no files selected for viewing
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
| Original file line number | Diff line number | Diff line change |
|---|---|---|
| @@ -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! |
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
| Original file line number | Diff line number | Diff line change |
|---|---|---|
| @@ -0,0 +1,60 @@ | ||
| 死锁 | ||
| === | ||
|
|
||
| ```java | ||
| /** | ||
| * 死锁的原因就是同步的嵌套 | ||
| */ | ||
| public class DeadLockTest { | ||
| public static void main(String[] args) { | ||
| Thread t1 = new Thread(new PrintRunnable(true)); | ||
| Thread t2 = new Thread(new PrintRunnable(false)); | ||
| t1.start(); | ||
| t2.start(); | ||
| } | ||
| } | ||
|
|
||
| class MyLock { | ||
| static Object locka = new Object(); | ||
| static Object lockb = new Object(); | ||
| } | ||
|
|
||
| class PrintRunnable implements Runnable { | ||
| private boolean flag; | ||
|
|
||
| PrintRunnable(boolean flag) { | ||
| this.flag = flag; | ||
| } | ||
|
|
||
| public void run() { | ||
| if (flag) { | ||
| while (true) { | ||
| synchronized (MyLock.locka) { | ||
| System.out.println(Thread.currentThread().getName() | ||
| + "...if locka "); | ||
| synchronized (MyLock.lockb) { | ||
| System.out.println(Thread.currentThread().getName() | ||
| + "..if lockb"); | ||
| } | ||
| } | ||
| } | ||
| } else { | ||
| while (true) { | ||
| synchronized (MyLock.lockb) { | ||
| System.out.println(Thread.currentThread().getName() | ||
| + "..else lockb"); | ||
| synchronized (MyLock.locka) { | ||
| System.out.println(Thread.currentThread().getName() | ||
| + ".....else locka"); | ||
| } | ||
| } | ||
| } | ||
| } | ||
| } | ||
| } | ||
| ``` | ||
|
|
||
| --- | ||
|
|
||
| - 邮箱 ：[email protected] | ||
| - Good Luck! |
Oops, something went wrong.