这篇文章记录使用ContentProvider的方法，，提供了最简单安全的移植方法
首先在工程目录建立包名对应的database目录
放入如下三个文件：
DBHelper.java:
package com.sprd.fileexplorer.database;import android.content.Context;import android.database.sqlite.SQLiteDatabase;import android.database.sqlite.SQLiteOpenHelper;import android.util.Log;/** * DBHelper * @author chrison.chai * */public final class DBHelper extends SQLiteOpenHelper {private static final String TAG = "DBHelper"; private static final int DB_VERSION = 1; private static final String DB_NAME = "fileexplorer.db"; public static final String ID = "_id";//favorate table public static final String TABLE_NAME_FAVORATE = "favorates"; public static final String FAVORATE_TITLE = "title"; public static final String FAVORATE_DATA = "_data"; public static final String FAVORATE_DATE_MODIFIED = "date_modified"; public static final String FAVORATE_SIZE = "_size";public DBHelper(Context context) {super(context, DB_NAME, null, DB_VERSION); }private SQLiteDatabase mWritableDatabase; private SQLiteDatabase mReadableDatabase;public synchronized SQLiteDatabase openWritableDatabase() { if (mWritableDatabase == null) {mWritableDatabase = getWritableDatabase(); } return mWritableDatabase; }public synchronized SQLiteDatabase openReadableDatabase() { if (mReadableDatabase == null) {mReadableDatabase = getReadableDatabase(); } return mReadableDatabase; }public synchronized void closeReadableDatabase() { if (mReadableDatabase != null && mReadableDatabase.isOpen()) {mReadableDatabase.close();mReadableDatabase = null; } }public synchronized void closeWritableDatabase() { if (mWritableDatabase != null && mWritableDatabase.isOpen()) {mWritableDatabase.close();mWritableDatabase = null; } }public synchronized void closeDatabase() { closeReadableDatabase(); closeWritableDatabase(); } @Override public void onCreate(SQLiteDatabase sqLiteDatabase) { Log.d("huasong", "oncreate db helper..");createFavorateTable(sqLiteDatabase); }private void createFavorateTable(SQLiteDatabase sqLiteDatabase) { sqLiteDatabase.execSQL("CREATE TABLE " + TABLE_NAME_FAVORATE + " (" +ID + " INTEGER PRIMARY KEY AUTOINCREMENT, " +FAVORATE_TITLE + " TEXT, " +FAVORATE_DATA + " TEXT, " +FAVORATE_DATE_MODIFIED + " TEXT, " +FAVORATE_SIZE + " TEXT" +");"); }@Override public void onUpgrade(SQLiteDatabase sqLiteDatabase, int oldVersion, int newVersion) { sqLiteDatabase.execSQL("DROP TABLE IF EXISTS "+ TABLE_NAME_FAVORATE + ";");onCreate(sqLiteDatabase); }}FavorateContent.java:
package com.sprd.fileexplorer.database;import android.content.ContentResolver;import android.content.ContentValues;import android.database.Cursor;import android.net.Uri;public class FavorateContent {public static final String PKG_NAME = "com.sprd.fileexplorer";public static final String AUTHORITY = PKG_NAME + ".provider.FavorateProvider";public static final String NOTIFIER_AUTHORITY = PKG_NAME + ".notify.FavorateProvider";public static final Uri CONTENT_URI = Uri.parse("content://" + AUTHORITY);public static final String _ID = "_id";public static final String[] COUNT_COLUMNS = new String[]{"count(*)"};public static final String[] ID_PROJECTION = new String[] {_ID};public static final int ID_PROJECTION_COLUMN = 0;public static class FavorateFile extends FavorateContent{public static final Uri CONTENT_URI = Uri.withAppendedPath(FavorateContent.CONTENT_URI, "favoratefile");}public static long existed(ContentResolver cr, Uri uri, String where, String[] selectionArgs) {long id = -1;Cursor c = cr.query(uri, ID_PROJECTION, where, selectionArgs, null);if (c != null) {if (c.moveToNext()) {id = c.getLong(0);}c.close();}return id;}public static int update(ContentResolver cr, Uri uri, ContentValues values, String where, String[] selectionArgs) {return cr.update(uri, values, where, selectionArgs);}public static Uri insert(ContentResolver cr, Uri uri, ContentValues values) {return cr.insert(uri, values);}public static int delete(ContentResolver cr, Uri uri, String where, String[] selectionArgs) {return cr.delete(uri, where, selectionArgs);}}FavorateProvider.java:package com.sprd.fileexplorer.database;import android.content.ContentProvider;import android.content.ContentResolver;import android.content.ContentUris;import android.content.ContentValues;import android.content.Context;import android.content.UriMatcher;import android.database.Cursor;import android.database.sqlite.SQLiteDatabase;import android.net.Uri;import android.provider.MediaStore;import android.text.TextUtils;import android.util.Log;public class FavorateProvider extends ContentProvider{private static final String TAG = "BjnoteProvider";private SQLiteDatabase mContactDatabase;private String[] mTables = new String[]{DBHelper.TABLE_NAME_FAVORATE,};private static final int BASE = 8;private static final int FAVORATE = 0x0000;private static final int FAVORATE_ID = 0x0001;private static final UriMatcher sURIMatcher = new UriMatcher(UriMatcher.NO_MATCH); static {// URI matching tableUriMatcher matcher = sURIMatcher;matcher.addURI(FavorateContent.AUTHORITY, "favoratefile", FAVORATE);matcher.addURI(FavorateContent.AUTHORITY, "favoratefile/#", FAVORATE_ID);}synchronized SQLiteDatabase getDatabase(Context context) {Log.d("huasong", "getDatabase..");// Always return the cached database, if we've got oneif (mContactDatabase != null) {return mContactDatabase;}DBHelper helper = new DBHelper(context);mContactDatabase = helper.getWritableDatabase();mContactDatabase.setLockingEnabled(true);return mContactDatabase;}@Overridepublic boolean onCreate() {Log.d("huasong", "onCreate return false..");return false;}/*** Wrap the UriMatcher call so we can throw a runtime exception if an unknown Uri is passed in* @param uri the Uri to match* @return the match value*/private static int findMatch(Uri uri, String methodName) {int match = sURIMatcher.match(uri);if (match < 0) {throw new IllegalArgumentException("Unknown uri: " + uri);}return match;}private void notifyChange(int match) {Context context = getContext();Uri notify = FavorateContent.CONTENT_URI;switch(match) {case FAVORATE:case FAVORATE_ID:notify = FavorateContent.FavorateFile.CONTENT_URI;break;}ContentResolver resolver = context.getContentResolver();resolver.notifyChange(notify, null);}@Overridepublic int delete(Uri uri, String selection, String[] selectionArgs) {int match = findMatch(uri, "delete");Context context = getContext();SQLiteDatabase db = getDatabase(context);String table = mTables[match>>BASE];int count = 0;switch(match) {default:count = db.delete(table, buildSelection(match, uri, selection), selectionArgs);}if (count >0) notifyChange(match);return count;}@Overridepublic String getType(Uri uri) {return null;}@Overridepublic Uri insert(Uri uri, ContentValues values) { int match = findMatch(uri, "insert");Context context = getContext();SQLiteDatabase db = getDatabase(context);String table = mTables[match>>BASE];if (values.containsKey(DBHelper.ID)) {values.remove(DBHelper.ID);}long id = db.insert(table, null, values);if (id > 0) {notifyChange(match);return ContentUris.withAppendedId(uri, id);} return null;}private static final String[] COLUMN_NAME = { MediaStore.Images.ImageColumns.DATA};@Overridepublic Cursor query(Uri uri, String[] projection, String selection,String[] selectionArgs, String sortOrder) { int match = findMatch(uri, "query");Context context = getContext();SQLiteDatabase db = getDatabase(context);int i =match>>BASE;String table = mTables[i];Cursor result = null;switch(match) {default:result = db.query(table, projection, selection, selectionArgs, null, null, sortOrder);}if(result != null)result.setNotificationUri(getContext().getContentResolver(), uri);return result;}@Overridepublic int update(Uri uri, ContentValues values, String selection,String[] selectionArgs) {int match = findMatch(uri, "update");Context context = getContext();SQLiteDatabase db = getDatabase(context);String table = mTables[match>>BASE];int count = 0;switch(match) {default:count = db.update(table, values, buildSelection(match, uri, selection), selectionArgs);}if (count >0) notifyChange(match);return count;}private String buildSelection(int match, Uri uri, String selection) {long id = -1;switch(match) {case FAVORATE_ID:try {id = ContentUris.parseId(uri);} catch(java.lang.NumberFormatException e) {e.printStackTrace();}break;}if (id == -1) {return selection;}StringBuilder sb = new StringBuilder();sb.append(DBHelper.ID);sb.append("=").append(id);if (!TextUtils.isEmpty(selection)) {sb.append(" and ");sb.append(selection);}return sb.toString();}}AndroidManifest.xml里面加入：
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