How to Use contentprovider for data storage in android

Metadata interface package com. example. contentproviderprojecrt; import android.net. uri; import android. provider. baseColumns; public interface MLDNbatabaseMetaData {// external access, content address: // com. example. contentproviderprojectpublic static final String AUTHORITY = "com. example. contentproviderproject "; // database name public static final String DATABASE_NAME =" mldn. db "; // The database VERSION public static final int VERSION = 1; // The Element Definition of the member table, directly inherited with _ ID and _ COUNT static variable public static interface MemberTableMetaData extends BaseColumns {// data table name public static final String TABLE_NAME = "member"; // The URI address for external access public static final Uri CONTENT_URI = Uri. parse ("content: //" + AUTHORITY + "/" + TABLE_NAME); // obtain all data in the member table public static final String CONTACT_LIST = "vnd. android. cursor. dir/vnd. contentproviderproject. member "; // get the public static final String CONTACT_ITEM =" vnd. Android. cursor. item/vnd. contentproviderproject. member "; // field name public static final String MEMBER_NAME =" name "; public static final String MEMBER_AGE =" age "; public static final String MEMBER_BIRTHDAY =" birthday "; // The sort field public static final String SORT_ORDER = "_ id DESC" ;}} displayed defines the database operation assistant package com. example. contentproviderprojecrt; import android. content. context; import android. database. sqlite. SQLiteDatabase; Import android. database. sqlite. SQLiteDatabase. cursorFactory; import android. database. sqlite. SQLiteOpenHelper; public class MyDatabaseHelper extends SQLiteOpenHelper {public MyDatabaseHelper (Context context) {// create a database super (context, MLDNbatabaseMetaData. DATABASE_NAME, null, MLDNbatabaseMetaData. VERSION) ;}@ Overridepublic void onCreate (SQLiteDatabase db) {// CREATE a TABLE String SQL = "CREATE TABLE" + MLDNbatabaseMeta Data. memberTableMetaData. TABLE_NAME + "(" + MLDNbatabaseMetaData. memberTableMetaData. _ ID + "integer primary key," + MLDNbatabaseMetaData. memberTableMetaData. MEMBER_NAME + "VARCHAR (50) not null," + MLDNbatabaseMetaData. memberTableMetaData. MEMBER_AGE + "integer not null," + MLDNbatabaseMetaData. memberTableMetaData. MEMBER_BIRTHDAY + "date not null" + ")" mongodb.exe cSQL (SQL); // Execute SQL statements} @ Overridepublic void onUpgrade (SQLi TeDatabase db, int oldVersion, int newVersion) {// update TABLE String SQL = "drop table if exists" comment mldnbatabasemetadata.membertablemetadata.table_name1_db.exe cSQL (SQL); // execute the SQL statement this. onCreate (db); // update database} defines the table operation contentProvider class package com. example. contentproviderprojecrt; import android. content. contentProvider; import android. content. contentUris; import android. content. contentValues; import android. content. uriMatc Her; import android. database. cursor; import android. database. sqlite. SQLiteDatabase; import android.net. uri; public class MemberContentProvider extends ContentProvider {private static UriMatcher uriMatcher = null; // defines the UriMatcher object private static final int GET_MEMBER_LIST = 1; // mark all constants in the query as private static final int GET_MEMBER_ITEM = 2; // mark private MyDatabaseHelper helper = null according to the constant in the ID query; // The static {uriMatcher of the database operation class Object = New UriMatcher (uriMatcher. NO_MATCH); // instantiate UriMatcheruriMatcher. addURI (MLDNbatabaseMetaData. AUTHORITY, MLDNbatabaseMetaData. memberTableMetaData. TABLE_NAME, GET_MEMBER_LIST); // Add the matching item uriMatcher. addURI (MLDNbatabaseMetaData. AUTHORITY, MLDNbatabaseMetaData. memberTableMetaData. TABLE_NAME + "/#", GET_MEMBER_ITEM); // Add a match} // delete data operation @ Overridepublic int delete (Uri uri, String selection, String [] selectionArgs) {S QLiteDatabase db = this. helper. getWritableDatabase (); // enable int result = 0 in write mode; // switch (uriMatcher. match (uri) {// match the imported Uricase GET_MEMBER_LIST: result = db. delete (MLDNbatabaseMetaData. memberTableMetaData. TABLE_NAME, selection, selectionArgs); break; case GET_MEMBER_ITEM: long id = ContentUris. parseId (uri); String where = "_ id =" + id; result = db. delete (MLDNbatabaseMetaData. memberTableMetaData. TABLE_NAME, where, sel EctionArgs); break; default: throw new UnsupportedOperationException ("not support operation" + uri);} return result ;}@ Overridepublic String getType (Uri uri) {switch (uriMatcher. match (uri) {// match the input Uricase GET_MEMBER_LIST: return MLDNbatabaseMetaData. memberTableMetaData. CONTACT_LIST; case GET_MEMBER_ITEM: return MLDNbatabaseMetaData. memberTableMetaData. CONTACT_ITEM; default: throw new UnsupportedOperationExcep Tion ("not support operation" + uri); // throw an exception} @ Overridepublic Uri insert (Uri uri, ContentValues values) {SQLiteDatabase db = this. helper. getWritableDatabase (); // enable long id = 0 in write mode; // The added IDswitch (uriMatcher. match (uri) {// match the imported Uricase GET_MEMBER_LIST: id = db. insert (MLDNbatabaseMetaData. memberTableMetaData. TABLE_NAME, MLDNbatabaseMetaData. memberTableMetaData. _ ID, values); String uriPath = uri. toString (); // retrieves the address S Tring path = uriPath + "/" + id; // create a new URI address, return Uri. parse (path); case GET_MEMBER_ITEM: return null; default: throw new UnsupportedOperationException ("not support operation" + uri) ;}@ Overridepublic boolean onCreate () {this. helper = new MyDatabaseHelper (super. getContext (); // instantiate DatabaseHelperreturn true; // operation successful} @ Overridepublic Cursor query (Uri uri, String [] projection, String selection, String [] selectionArg S, String sortOrder) {SQLiteDatabase db = this. helper. getReadableDatabase (); // open the switch (uriMatcher. match (uri) {// match the input Uricase GET_MEMBER_LIST: return db. query (MLDNbatabaseMetaData. memberTableMetaData. TABLE_NAME, projection, selection, selectionArgs, null, null, sortOrder); case GET_MEMBER_ITEM: long id = ContentUris. parseId (uri); String where = "_ id =" + id; return db. query (MLDNbatabaseMetaData. memberTableM EtaData. TABLE_NAME, projection, where, selectionArgs, null, null, sortOrder); default: throw new UnsupportedOperationException ("not support operation" + uri); }}@ Overridepublic int update (Uri uri, contentValues values, String selection, String [] selectionArgs) {SQLiteDatabase db = this. helper. getWritableDatabase (); // enable int result = 0 in write mode; // switch (uriMatcher. match (uri) {// match the imported Uricase GET_MEMBER_LIST: r Esult = db. update (MLDNbatabaseMetaData. memberTableMetaData. TABLE_NAME, values, null, null); break; case GET_MEMBER_ITEM: long id = ContentUris. parseId (uri); String where = "_ id =" + id; result = db. update (MLDNbatabaseMetaData. memberTableMetaData. TABLE_NAME, values, where, selectionArgs); break; default: throw new UnsupportedOperationException ("not support operation" + uri);} return result ;}} Acitivity Program package com. ex Ample. contentproviderprojecrt; import java. text. simpleDateFormat; import java. util. arrayList; import java. util. date; import java. util. hashMap; import java. util. list; import java. util. map; import android.net. uri; import android. OS. bundle; import android. app. activity; import android. content. contentResolver; import android. content. contentUris; import android. content. contentValues; import android. database. cursor; I Mport android. view. menu; import android. view. view; import android. view. view. onClickListener; import android. widget. button; import android. widget. listView; import android. widget. simpleAdapter; import android. widget. toast; public class MainActivity extends Activity {private Button insertBut = null; private Button updateBut = null; private Button deleteBut = null; private Button queryBut = null; private ListView me MberList = null; @ Overrideprotected void onCreate (Bundle savedInstanceState) {super. onCreate (savedInstanceState); super. setContentView (R. layout. activity_main); this. insertBut = (Button) super. findViewById (R. id. insertBut); // obtain the button this. insertBut. setOnClickListener (new InsertOnClickListener (); // click the event this. updateBut = (Button) super. findViewById (R. id. updateBut); // obtain the button this. updateBut. setOnClickListener (new Update OnClickListener (); // click the event this. deleteBut = (Button) super. findViewById (R. id. deleteBut); // obtain the button this. deleteBut. setOnClickListener (new DeleteOnClickListener (); // click the event this. queryBut = (Button) super. findViewById (R. id. queryBut); // obtain the button this. queryBut. setOnClickListener (new QueryOnClickListener (); // click the event this. memberList = (ListView) super. findViewById (R. id. memberList); // get ListView} private class QueryOnClick Listener implements OnClickListener {// query button event @ Overridepublic void onClick (View v) {Cursor result = MainActivity. this. textQuery (null); // query result set List <Map <String, Object> list = new ArrayList <Map <String, Object> (); // set SimpleAdapterfor (result. moveToFirst ();! Result. isAfterLast (); result. moveToNext () {// cyclically retrieve the data Map <String, Object> map = new HashMap <String, Object> (); map. put ("_ id", result. getInt (0); map. put ("name", result. getString (1); map. put ("age", result. getInt (2); map. put ("birthday", result. getString (3); list. add (map); // Save the Retrieved Data} MainActivity. this. memberList. setAdapter (new SimpleAdapter (MainActivity. this, // encapsulate the data list, // data set R. layout. member, // display layout file new String [] {"_ id", "name", "age", "birthday"}, // matched Map key new int [] {R. id. _ id, R. id. name, R. id. age, R. id. birthday}); // ID in the layout file} private class DeleteOnClickListener implements OnClickListener {// delete button event @ Overridepublic void onClick (View v) {long result = 0; // return the number of deleted data records. result = MainActivity. this. textDelete (String. valueOf (2); Toast. makeText (MainActivity. this, "result =" + result, Toast. LENGTH_LONG ). show () ;}} priv Ate class UpdateOnClickListener implements OnClickListener {// Update button event @ Overridepublic void onClick (View v) {long result = 0; // return the number of updated data records result = MainActivity. this. textUpdate ("1", "Li yuanjing", 18, "1998-01-01"); Toast. makeText (MainActivity. this, "result =" + result, Toast. LENGTH_LONG ). show () ;}} private class InsertOnClickListener implements OnClickListener {// Add button event @ Overridepublic void onClick (View v) {long id = 0; // save Accept IDid = MainActivity. this. textInsert ("Li yuanjing", 21, new SimpleDateFormat ("yyyy-MM-dd "). format (new Date (); Toast. makeText (MainActivity. this, "id =" + id, Toast. LENGTH_LONG ). show () ;}} private Cursor textQuery (String _ id) {if (_ id = null | "". equals (_ id) {// query all data return super. getContentResolver (). query (MLDNbatabaseMetaData. memberTableMetaData. CONTENT_URI, null, MLDNbatabaseMetaData. memberTableMetaDa Ta. SORT_ORDER);} else {// query the specified ID data return super. getContentResolver (). query (Uri. withAppendedPath (MLDNbatabaseMetaData. memberTableMetaData. CONTENT_URI, _ id), null, MLDNbatabaseMetaData. memberTableMetaData. SORT_ORDER) ;}} private long textDelete (String _ id) {ContentResolver contentSesolver = super. getContentResolver (); // define to obtain the ContentResolver object int result = 0; if (_ id = null | "". equals (_ id) {// delete all data resul T = contentSesolver. delete (MLDNbatabaseMetaData. memberTableMetaData. CONTENT_URI, null, null);} else {// Delete the specified data result = contentSesolver. delete (Uri. withAppendedPath (MLDNbatabaseMetaData. memberTableMetaData. CONTENT_URI, _ id), null, null);} return result;} private long textInsert (String name, int age, String birthday) {ContentResolver contentSesolver = null; // define ContentResolvercontentSesolver = super. getContentResolve R (); // get contentSesolverContentValues values = new ContentValues (); // set the content values. put (MLDNbatabaseMetaData. memberTableMetaData. MEMBER_NAME, name); values. put (MLDNbatabaseMetaData. memberTableMetaData. MEMBER_AGE, age); values. put (MLDNbatabaseMetaData. memberTableMetaData. MEMBER_BIRTHDAY, birthday); Uri resultUri = contentSesolver. insert (MLDNbatabaseMetaData. memberTableMetaData. CONTENT_URI, values); return Conte NtUris. parseId (resultUri); // resolution ID returned} private long textUpdate (String _ id, String name, int age, String birthday) {long result = 0; ContentResolver contentSesolver = null; // define ContentResolvercontentSesolver = super. getContentResolver (); // get contentSesolverContentValues values = new ContentValues (); // set the content values. put (MLDNbatabaseMetaData. memberTableMetaData. MEMBER_NAME, name); values. put (MLDNbatabaseMetaData. memberTabl EMetaData. MEMBER_AGE, age); values. put (MLDNbatabaseMetaData. memberTableMetaData. MEMBER_BIRTHDAY, birthday); if (_ id = null | "". equals (_ id) {// update all result = contentSesolver. update (MLDNbatabaseMetaData. memberTableMetaData. CONTENT_URI, values, null, null);} else {// update formulated data result = contentSesolver. update (Uri. withAppendedPath (MLDNbatabaseMetaData. memberTableMetaData. CONTENT_URI, _ id), values, null, null);} Uri res UltUri = contentSesolver. insert (MLDNbatabaseMetaData. memberTableMetaData. CONTENT_URI, values); return result;} @ Overridepublic boolean onCreateOptionsMenu (Menu menu) {// Inflate the menu; this adds items to the action bar if it is present. getMenuInflater (). inflate (R. menu. main, menu); return true ;}} Layout: activity_mail.xml <LinearLayout xmlns: android = "http://schemas.android.com/apk/res/android" android: Orientation = "vertical" android: layout_width = "fill_parent" android: layout_height = "fill_parent"> <LinearLayout android: orientation = "horizontal" android: layout_width = "fill_parent" android: layout_height = "wrap_content"> <Button android: id = "@ + id/insertBut" android: layout_width = "wrap_content" android: layout_height = "wrap_content" android: text = "add data"/> <Button android: id = "@ + id/updateBut" android: layout _ Width = "wrap_content" android: layout_height = "wrap_content" android: text = "modify data"/> <Button android: id = "@ + id/deleteBut" android: layout_width = "wrap_content" android: layout_height = "wrap_content" android: text = "delete data"/> <Button android: id = "@ + id/queryBut" android: layout_width = "wrap_content" android: layout_height = "wrap_content" android: text = "query data"/> </LinearLayout> <ListView android: id = "@ + id/memberList" androi D: layout_width = "wrap_content" android: layout_height = "wrap_content"/> </LinearLayout> member. xml <? Xml version = "1.0" encoding = "UTF-8"?> <TableLayout xmlns: android = "http://schemas.android.com/apk/res/android" android: layout_width = "wrap_content" android: layout_height = "wrap_content"> <TableRow> <TextView android: id = "@ + id/_ id" android: layout_width = "30px" android: layout_height = "wrap_content"/> <TextView android: id = "@ + id/name" android: layout_width = "100px" android: layout_height = "wrap_content"/> <TextView android: id = "@ + id/age" android: layout_width = "30px" android: layout_height = "wrap_content"/> <TextView android: id = "@ + id/birthday" android: layout_width = "150px" android: layout_height = "wrap_content"/> </TableRow> </TableLayout>