常用简单的ContentProvider的实现差不多,整理了个通用的(基于com.example.android.supportv4.app.LoaderThrottleSupport.SimpleProvider修改), 从这个类继承，再重写几个方法就可以了,测试代码见附件。
import java.util.HashMap;
import android.content.ContentProvider;
import android.content.ContentUris;
import android.content.ContentValues;
import android.content.Context;
import android.content.UriMatcher;
import android.database.Cursor;
import android.database.SQLException;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;
import android.database.sqlite.SQLiteQueryBuilder;
import android.net.Uri;
import android.provider.BaseColumns;
import android.support.v4.database.DatabaseUtilsCompat;
import android.text.TextUtils;
/**
*
* @author J
*
*/
public abstract class SimpleContentProvider extends ContentProvider{
public static final String CONTENT_TYPE = "vnd.android.cursor.dir/vnd.%s.%s";
public static final String CONTENT_ITEM_TYPE = "vnd.android.cursor.item/vnd.%s.%s";
private final UriMatcher mUriMatcher = new UriMatcher(UriMatcher.NO_MATCH);
//
private HashMap<Integer, String> hash_id_tableName = new HashMap<Integer, String>();
private SQLiteOpenHelper mOpenHelper;
protected abstract String getAuthority();
protected abstract SQLiteOpenHelper createDatabaseHelper(Context context);
protected abstract String[] getTableNames();
protected String getIdName(String tableName){
return BaseColumns._ID;
}
protected String getDefaultSort(String tableName){
return null;
}
/**
* If URI is main table
*/
private boolean isMain(int id){
return id % 2 == 1;
}
/**
* Global provider initialization.
*/
public SimpleContentProvider() {
int id_main = 1, id_row = 2;
String[] tableNames = getTableNames();
for (String tableName : tableNames){
//奇数 for main table, 偶数 for row
mUriMatcher.addURI(getAuthority(), tableName, id_main);
mUriMatcher.addURI(getAuthority(), tableName + "/#", id_row);
hash_id_tableName.put(id_main, tableName);
hash_id_tableName.put(id_row, tableName);
id_main += 2;
id_row += 2;
}
}
@Override
public boolean onCreate() {
mOpenHelper = createDatabaseHelper(getContext());
return true;
}
@Override
public Cursor query(Uri uri, String[] projection, String selection,
String[] selectionArgs, String sortOrder) {
// Constructs a new query builder and sets its table name
SQLiteQueryBuilder qb = new SQLiteQueryBuilder();
int id = mUriMatcher.match(uri);
String tableName = hash_id_tableName.get(id);
if (tableName != null){
qb.setTables(tableName);
if (isMain(id)){
//qb.setProjectionMap(mNotesProjectionMap);
}
else{
//qb.setProjectionMap(mNotesProjectionMap);
qb.appendWhere(getIdName(tableName) + "=?");
selectionArgs = DatabaseUtilsCompat.appendSelectionArgs(selectionArgs,
new String[] { uri.getLastPathSegment() });
}
}
else{
throw new IllegalArgumentException("Unknown URI " + uri);
}
if (TextUtils.isEmpty(sortOrder)) {
sortOrder = getDefaultSort(tableName);
}
SQLiteDatabase db = mOpenHelper.getReadableDatabase();
Cursor c = qb.query(db, projection, selection, selectionArgs, null, null, sortOrder);
c.setNotificationUri(getContext().getContentResolver(), uri);
return c;
}
/**
* Return the MIME type for an known URI in the provider.
*/
@Override
public String getType(Uri uri) {
int id = mUriMatcher.match(uri);
String tableName = hash_id_tableName.get(id);
if (tableName != null){
if (isMain(id)){
return String.format(CONTENT_TYPE, getAuthority(), tableName);
}
else{
return String.format(CONTENT_ITEM_TYPE, getAuthority(), tableName);
}
}
else{
throw new IllegalArgumentException("Unknown URI " + uri);
}
}
/**
* Handler inserting new data.
*/
@Override
public Uri insert(Uri uri, ContentValues initialValues) {
int id = mUriMatcher.match(uri);
String tableName = hash_id_tableName.get(id);
if (tableName == null || !isMain(id)){
// Can only insert into to main URI.
throw new IllegalArgumentException("Unknown URI " + uri);
}
ContentValues values;
if (initialValues != null) {
values = new ContentValues(initialValues);
} else {
values = new ContentValues();
}
SQLiteDatabase db = mOpenHelper.getWritableDatabase();
long rowId = db.insert(tableName, null, values);
// If the insert succeeded, the row ID exists.
if (rowId > 0) {
//Uri noteUri = ContentUris.withAppendedId(MainTable.CONTENT_ID_URI_BASE, rowId);
Uri noteUri = ContentUris.withAppendedId(uri, rowId);
getContext().getContentResolver().notifyChange(noteUri, null);
return noteUri;
}
throw new SQLException("Failed to insert row into " + uri);
}
/**
* Handle deleting data.
*/
@Override
public int delete(Uri uri, String where, String[] whereArgs) {
SQLiteDatabase db = mOpenHelper.getWritableDatabase();
String finalWhere;
int count;
int id = mUriMatcher.match(uri);
String tableName = hash_id_tableName.get(id);
if (tableName != null){
if (isMain(id)){
count = db.delete(tableName, where, whereArgs);
}
else{
finalWhere = DatabaseUtilsCompat.concatenateWhere(
getIdName(tableName) + " = " + ContentUris.parseId(uri), where);
count = db.delete(tableName, finalWhere, whereArgs);
}
}
else{
throw new IllegalArgumentException("Unknown URI " + uri);
}
getContext().getContentResolver().notifyChange(uri, null);
return count;
}
/**
* Handle updating data.
*/
@Override
public int update(Uri uri, ContentValues values, String where, String[] whereArgs) {
SQLiteDatabase db = mOpenHelper.getWritableDatabase();
int count;
String finalWhere;
int id = mUriMatcher.match(uri);
String tableName = hash_id_tableName.get(id);
if (tableName != null){
if (isMain(id)){
// If URI is main table, update uses incoming where clause and args.
count = db.update(tableName, values, where, whereArgs);
}
else{
// If URI is for a particular row ID, update is based on incoming
// data but modified to restrict to the given ID.
finalWhere = DatabaseUtilsCompat.concatenateWhere(
getIdName(tableName) + " = " + ContentUris.parseId(uri), where);
count = db.update(tableName, values, finalWhere, whereArgs);
}
}
else{
throw new IllegalArgumentException("Unknown URI " + uri);
}
getContext().getContentResolver().notifyChange(uri, null);
return count;
}
}