/*
* Copyright (C) Tony Green, Litepal Framework Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.litepal.parser;
import java.io.IOException;
import java.io.InputStream;
import javax.xml.parsers.ParserConfigurationException;
import javax.xml.parsers.SAXParserFactory;
import org.litepal.LitePalApplication;
import org.litepal.exceptions.ParseConfigurationFileException;
import org.litepal.util.Const;
import org.xml.sax.InputSource;
import org.xml.sax.SAXException;
import org.xml.sax.XMLReader;
import org.xmlpull.v1.XmlPullParser;
import org.xmlpull.v1.XmlPullParserException;
import org.xmlpull.v1.XmlPullParserFactory;
import android.content.res.AssetManager;
import android.content.res.Resources.NotFoundException;
/**
* The class is used to parse the litepal.xml file. There're three usual ways to
* parse XML in android, SAX, Pull and DOM. LitePal use SAX as default option,
* and DOM parser will be added soon.
*
* @author Tony Green
* @since 1.0
*/
public class LitePalParser {
/**
* Node name dbname.
*/
static final String NODE_DB_NAME = "dbname";
/**
* Node name version.
*/
static final String NODE_VERSION = "version";
/**
* Node name list. Currently not used.
*/
static final String NODE_LIST = "list";
/**
* Node name mapping.
*/
static final String NODE_MAPPING = "mapping";
/**
* Node name column case.
*/
static final String NODE_CASES = "cases";
/**
* Attribute name value, for dbname and version node.
*/
static final String ATTR_VALUE = "value";
/**
* Attribute name class, for mapping node.
*/
static final String ATTR_CLASS = "class";
/**
* Store the parsed value of litepal.xml.
*/
private static LitePalParser parser;
/**
* Analyze litepal.xml, and store the analyzed result in LitePalParser. Use
* DomParse to parse the configuration file as default. SAXParser and
* XmlPullParser is also optional, but not visible to developers.
*/
public static void parseLitePalConfiguration() {
if (parser == null) {
parser = new LitePalParser();
}
parser.useSAXParser();
}
/**
* Use SAXParser to parse the litepal.xml file. It will get the parsed
* result from LitePalContentHandler and stored in the instance of
* LitePalAttr.
*
* Note while analyzing litepal.xml file, ParseConfigurationFileException
* could be thrown. Be careful of writing litepal.xml file, or developer's
* application may be crash.
*/
void useSAXParser() {
LitePalContentHandler handler = null;
try {
SAXParserFactory factory = SAXParserFactory.newInstance();
XMLReader xmlReader = factory.newSAXParser().getXMLReader();
handler = new LitePalContentHandler();
xmlReader.setContentHandler(handler);
xmlReader.parse(new InputSource(getConfigInputStream()));
return;
} catch (NotFoundException e) {
throw new ParseConfigurationFileException(
ParseConfigurationFileException.CAN_NOT_FIND_LITEPAL_FILE);
} catch (SAXException e) {
throw new ParseConfigurationFileException(
ParseConfigurationFileException.FILE_FORMAT_IS_NOT_CORRECT);
} catch (ParserConfigurationException e) {
throw new ParseConfigurationFileException(
ParseConfigurationFileException.PARSE_CONFIG_FAILED);
} catch (IOException e) {
throw new ParseConfigurationFileException(ParseConfigurationFileException.IO_EXCEPTION);
}
}
/**
* Use XmlPullParser to parse the litepal.xml file. It will store the result
* in the instance of LitePalAttr.
*
* Note while analyzing litepal.xml file, ParseConfigurationFileException
* could be thrown. Be careful of writing litepal.xml file, or developer's
* application may be crash.
*/
void usePullParse() {
try {
LitePalAttr litePalAttr = LitePalAttr.getInstance();
XmlPullParserFactory factory = XmlPullParserFactory.newInstance();
XmlPullParser xmlPullParser = factory.newPullParser();
xmlPullParser.setInput(getConfigInputStream(), "UTF-8");
int eventType = xmlPullParser.getEventType();
while (eventType != XmlPullParser.END_DOCUMENT) {
String nodeName = xmlPullParser.getName();
switch (eventType) {
case XmlPullParser.START_TAG: {
if (NODE_DB_NAME.equals(nodeName)) {
String dbName = xmlPullParser.getAttributeValue("", ATTR_VALUE);
litePalAttr.setDbName(dbName);
} else if (NODE_VERSION.equals(nodeName)) {
String version = xmlPullParser.getAttributeValue("", ATTR_VALUE);
litePalAttr.setVersion(Integer.parseInt(version));
} else if (NODE_MAPPING.equals(nodeName)) {
String className = xmlPullParser.getAttributeValue("", ATTR_CLASS);
litePalAttr.addClassName(className);
} else if (NODE_CASES.equals(nodeName)) {
String cases = xmlPullParser.getAttributeValue("", ATTR_VALUE);
litePalAttr.setCases(cases);
}
break;
}
default:
break;
}
eventType = xmlPullParser.next();
}
} catch (XmlPullParserException e) {
throw new ParseConfigurationFileException(
ParseConfigurationFileException.FILE_FORMAT_IS_NOT_CORRECT);
} catch (IOException e) {
throw new ParseConfigurationFileException(ParseConfigurationFileException.IO_EXCEPTION);
}
}
/**
* Iterates all files in the root of assets folder. If find litepal.xml,
* open this file and return the input stream. Or throw
* ParseConfigurationFileException.
*
* @return The input stream of litepal.xml.
* @throws IOException
*/
private InputStream getConfigInputStream() throws IOException {
AssetManager assetManager = LitePalApplication.getContext().getAssets();
String[] fileNames = assetManager.list("");
if (fileNames != null && fileNames.length > 0) {
for (String fileName : fileNames) {
if (Const.LitePal.CONFIGURATION_FILE_NAME.equalsIgnoreCase(fileName)) {
return assetManager.open(fileName, AssetManager.ACCESS_BUFFER);
}
}
}
throw new ParseConfigurationFileException(
ParseConfigurationFileException.CAN_NOT_FIND_LITEPAL_FILE);
}
}