Android development path 13 ---- ContentProvider connection

ContentProvider

1. PersonProvider

Package cn. class3g. db;   Import cn. class3g. service. DatabaseHelper; Import android. content. ContentProvider; Import android. content. ContentUris; Import android. content. ContentValues; Import android. content. UriMatcher; Import android. database. Cursor; Import android. database. sqlite. SQLiteDatabase; Import android.net. Uri;   Public class PersonProvider extends ContentProvider { Private static UriMatcher matcher = new UriMatcher (UriMatcher. NO_MATCH );   Private static final int PERSONS = 1; Private static final int PERSON = 2;   Private DatabaseHelper dbHelper;   Static { Matcher. addURI ("cn. class3g. providers. personprovider", "person", PERSONS ); Matcher. addURI ("cn. class3g. providers. personprovider", "person /#", PERSON ); }   Public boolean onCreate (){ DbHelper = new DatabaseHelper (this. getContext ()); Return true; }   // Content: // cn. itcast. provides. personprovider/person Public Uri insert (Uri uri, ContentValues values ){ SQLiteDatabase db = dbHelper. getWritableDatabase (); Long rowId;   Switch (matcher. match (uri )){ Case PERSONS: // Add a new record to the table and return its row number RowId = db. insert ("person", "personid", values ); Return ContentUris. withAppendedId (uri, rowId ); Default: Throw new IllegalArgumentException ("Unknow Uri:" + uri ); } }   Public Cursor query (Uri uri, String [] projection, String selection, String [] selectionArgs, String sortOrder ){ SQLiteDatabase db = dbHelper. getReadableDatabase (); Switch (matcher. match (uri )){ Case PERSONS: Return db. query ("person", projection, selection, selectionArgs, null, null, sortOrder ); Case PERSON: Long personid = ContentUris. parseId (uri ); String where = "personid =" + personid; If (selection! = Null &&! "". Equals (selection )){ Where = where + "and" + selection; } Return db. query ("person", projection, where, selectionArgs, null, null, sortOrder ); Default: Throw new IllegalArgumentException ("Unknown Uri:" + uri ); } }   // Content: // CN. itcast. Provides. personprovider/person update all records in the table // Content: // CN. itcast. Provides. personprovider/person/10 update the record of the specified ID in the table Public int Update (URI Uri, contentvalues values, string selection, String [] selectionargs ){ Sqlitedatabase DB = dbhelper. getwritabledatabase (); Int num; Switch (matcher. match (uri )){ Case PERSONS: // update a specified record Num = db. update ("person", values, selection, selectionArgs ); Break; Case PERSON: Long personid = ContentUris. parseId (uri ); String where = "personid =" + personid; If (selection! = Null ){ Where + = "and" + selection; } Num = db. update ("person", values, where, selectionArgs ); Break; Default: Throw new IllegalArgumentException ("Unknow Uri" + uri ); } Return num; }   Public int delete (Uri uri, String selection, String [] selectionArgs ){ SQLiteDatabase db = dbHelper. getWritableDatabase (); Int num = 0; Switch (matcher. match (uri )){ Case PERSONS: Num = db. delete ("person", selection, selectionArgs ); Break; Case PERSON: Long personid = ContentUris. parseId (uri ); String where = "personid =" + personid; If (selection! = Null &&! "". Equals (selection )){ Where = where + "and" + selection; } Num = db. delete ("person", where, selectionArgs ); Break; Default: Throw new IllegalArgumentException ("Unknown Uri:" + uri ); } Return num; }   Public String getType (Uri uri ){ Switch (matcher. match (uri )){ Case PERSONS: Return "vnd. android. cursor. dir/person "; Case PERSON: Return "vnd. android. cursor. item/person "; Default: Throw new IllegalArgumentException ("Unknown Uri:" + uri ); } } }

2. Configuration

<Provider Android: Authorities ="Cn. class3g. providers. personprovider" Android: Name ="Personprovider"> </Provider>

3. Create a test project and compile the test code.

PackageCN. class3g. Visitor;   ImportAndroid. content. contentresolver; ImportAndroid. content. contentvalues; ImportAndroid. database. cursor; ImportAndroid.net. Uri; ImportAndroid. Test. androidtestcase; ImportAndroid. util. log;   Public classAccesscontentprovidertestExtendsAndroidtestcase { Public voidTestsave ()ThrowsThrowable { ContentResolver resolver =This. GetContext (). getContentResolver (); Uri insertUri = Uri.Parse("Content: // cn. class3g. providers. personprovider/person "); ContentValues values =NewContentValues (); Values. put ("name", "laozhang "); Values. put ("age", "50 "); Uri uri = resolver. insert (insertUri, values ); Log.I("TAG", uri. toString ()); } Public voidTestQuery ()ThrowsThrowable { ContentResolver resolver =This. GetContext (). getContentResolver (); Uri uri = Uri.Parse("Content: // cn. class3g. providers. personprovider/person "); Cursor cursor = resolver. query (uri,Null, Null,Null, "Personid asc "); While(Cursor. moveToNext ()){ IntPersonid = cursor. getInt (cursor. getColumnIndex ("personid ")); String name = cursor. getString (cursor. getColumnIndex ("name ")); Log.I("TAG", "personid =" + personid + ", name =" + name ); } Cursor. close (); } Public voidTestUpdate ()ThrowsThrowable { ContentResolver contentResolver =This. GetContext (). getContentResolver (); Uri updateUri = Uri.Parse("Content: // cn. class3g. providers. personprovider/person/5 "); ContentValues values =NewContentValues (); Values. Put ("name", "Chiang Kai-shek "); Contentresolver. Update (updateuri, values,Null, Null); } Public voidTestdelete ()ThrowsThrowable { Contentresolver =This. Getcontext (). getcontentresolver (); Uri uri = Uri.Parse("Content: // CN. class3g. providers. personprovider/person/5 "); Contentresolver. Delete (Uri,Null, Null); } }

 

4. Test (deploy the provider owner project to the device first)

5. ContentProvider listener