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 table
UriMatcher 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 one
if (mContactDatabase != null) {
return mContactDatabase;
}
DBHelper helper = new DBHelper(context);
mContactDatabase = helper.getWritableDatabase();
mContactDatabase.setLockingEnabled(true);
return mContactDatabase;
}
@Override
public 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);
}
@Override
public 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;
}
@Override
public String getType(Uri uri) {
return null;
}
@Override
public 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};
@Override
public 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;
}
@Override
public 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：
<provider android:name="com.sprd.fileexplorer.database.FavorateProvider"
android:authorities="com.sprd.fileexplorer.provider.FavorateProvider"/>调用insert方法保存数据：
ContentValues values = new ContentValues();
values.put(DBHelper.FAVORATE_TITLE, mClickedFile.getName());
values.put(DBHelper.FAVORATE_DATA, mClickedFile.getPath());
values.put(DBHelper.FAVORATE_DATE_MODIFIED, System.currentTimeMillis());
values.put(DBHelper.FAVORATE_SIZE, mClickedFile.length());
FavorateContent.insert(mContext.getContentResolver(), FavorateContent.FavorateFile.CONTENT_URI, values);调用uri = FavorateContent.FavorateFile.CONTENT_URI;进行查询数据库的值
原文地址：http://blog.csdn.net/chaihuasong/article/details/46049523
