/*******************************************************************************
* Copyright (c) 1998, 2015 Oracle and/or its affiliates. All rights reserved.
* This program and the accompanying materials are made available under the
* terms of the Eclipse Public License v1.0 and Eclipse Distribution License v. 1.0
* which accompanies this distribution.
* The Eclipse Public License is available at http://www.eclipse.org/legal/epl-v10.html
* and the Eclipse Distribution License is available at
* http://www.eclipse.org/org/documents/edl-v10.php.
*
* Contributors:
* Oracle - initial API and implementation from Oracle TopLink
******************************************************************************/
package org.eclipse.persistence.internal.helper;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.security.AccessController;
import java.security.PrivilegedAction;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;
import java.util.regex.Pattern;
import java.util.regex.PatternSyntaxException;
import org.eclipse.persistence.logging.SessionLog;
/**
* @author Mitesh Meswani
* This class is responsible to translate given database name to a DatabasePlatform.
*/
public class DBPlatformHelper {
private static final String DEFAULTPLATFORM = "org.eclipse.persistence.platform.database.DatabasePlatform"; // NOI18N
private final static String PROPERTY_PATH = "org/eclipse/persistence/internal/helper/"; // NOI18N
private final static String VENDOR_NAME_TO_PLATFORM_RESOURCE_NAME =
PROPERTY_PATH + "VendorNameToPlatformMapping.properties"; //NOI18N
/**
* Holds mapping between possible vendor names to internal platforms defined above.
* vendor names are treated as regular expressions.
*/
private static List<String[]> _nameToVendorPlatform = null;
/** Get Database Platform from vendor name.
* @param vendorName Input vendor name. Typically this is obtained by querying
* <code>DatabaseMetaData</code>.
* @param logger The logger.
* @return Database platform that corresponds to <code>vendorName</code>.
* If vendorName does not match any of predefined vendor names, <code>
* DEFAULTPLATFORM </code> is returned.
*/
public static String getDBPlatform(String vendorName, SessionLog logger) {
initializeNameToVendorPlatform(logger);
String detectedDbPlatform = null;
if(vendorName != null) {
detectedDbPlatform = matchVendorNameInProperties(vendorName, _nameToVendorPlatform, logger);
}
if (logger.shouldLog(SessionLog.FINE) ) {
logger.log(SessionLog.FINE, SessionLog.CONNECTION, "dbPlatformHelper_detectedVendorPlatform", detectedDbPlatform ); // NOI18N
}
if (detectedDbPlatform == null) {
if(logger.shouldLog(SessionLog.INFO)) {
logger.log(SessionLog.INFO, SessionLog.CONNECTION, "dbPlatformHelper_defaultingPlatform", vendorName, DEFAULTPLATFORM); // NOI18N
}
detectedDbPlatform = DEFAULTPLATFORM;
}
return detectedDbPlatform;
}
/**
* Allocate and initialize nameToVendorPlatform if not already done.
*/
private static List<String[]> initializeNameToVendorPlatform(SessionLog logger) {
synchronized(DBPlatformHelper.class) {
if(_nameToVendorPlatform == null) {
_nameToVendorPlatform = new ArrayList<String[]>();
try {
loadFromResource(_nameToVendorPlatform, VENDOR_NAME_TO_PLATFORM_RESOURCE_NAME,
DBPlatformHelper.class.getClassLoader() );
} catch (IOException e) {
logger.log(SessionLog.WARNING, SessionLog.CONNECTION, "dbPlatformHelper_noMappingFound", VENDOR_NAME_TO_PLATFORM_RESOURCE_NAME);
}
}
}
return _nameToVendorPlatform;
}
/**
* Match vendorName in properties specified by _nameToVendorPlatform.
*/
private static String matchVendorNameInProperties(String vendorName,
List<String[]> nameToVendorPlatform, SessionLog logger) {
String dbPlatform = null;
//Iterate over all properties till we find match.
for( Iterator<String[]> iterator = nameToVendorPlatform.iterator();
dbPlatform == null && iterator.hasNext();) {
String[] entry = iterator.next();
String regExpr = entry[0];
String value = entry[1];
if (logger.shouldLog(SessionLog.FINEST)) {
logger.log(SessionLog.FINEST, SessionLog.CONNECTION, "dbPlatformHelper_regExprDbPlatform", regExpr,
value); // NOI18N
}
if( matchPattern(regExpr, vendorName, logger) ) {
dbPlatform = value;
}
}
return dbPlatform;
}
/** Matches target to pattern specified regExp. Returns false if there is
* any error compiling regExp.
* @param regExp The regular expression.
* @param target The target against which we are trying to match regExp.
* @param logger
* @return false if there is error compiling regExp or target does not
* match regExp. true if regExp matches pattern.
*/
private static boolean matchPattern(String regExp, String target, SessionLog logger) {
boolean matches = false;
try {
matches = Pattern.matches(regExp,target);
} catch (PatternSyntaxException e){
if(logger.shouldLog(SessionLog.FINE)) {
logger.log(SessionLog.FINE, SessionLog.CONNECTION, "dbPlatformHelper_patternSyntaxException", e); // NOI18N
}
}
return matches;
}
//-----Property Loading helper methods ----/
private static void loadFromResource(List<String[]> properties, String resourceName, ClassLoader classLoader)
throws IOException {
load(properties, resourceName, classLoader);
}
/**
* Loads properties list from the specified resource
* into specified Properties object.
* @param properties Properties object to load
* @param resourceName Name of resource.
* If loadFromFile is true, this is fully qualified path name to a file.
* param classLoader is ignored.
* If loadFromFile is false,this is resource name.
* @param classLoader The class loader that should be used to load the resource. If null,primordial
* class loader is used.
*/
private static void load(List<String[]> properties, final String resourceName,
final ClassLoader classLoader)
throws IOException {
try (BufferedReader bin = new BufferedReader(
new InputStreamReader(openResourceInputStream(resourceName,classLoader)))) {
for (String line = bin.readLine(); line != null; line = bin.readLine()) {
String[] keyValue = validateLineForReturnAsKeyValueArray(line);
if (keyValue != null) {
properties.add(keyValue);
}
}
}
}
/**
* Open resourceName as input stream inside doPriviledged block
*/
private static InputStream openResourceInputStream(final String resourceName, final ClassLoader classLoader) {
return (InputStream) AccessController.doPrivileged(
new PrivilegedAction() {
public Object run() {
if (classLoader != null) {
return classLoader.getResourceAsStream(resourceName);
} else {
return ClassLoader.getSystemResourceAsStream(resourceName);
}
}
}
);
}
private static String[] validateLineForReturnAsKeyValueArray(String line) {
if (line == null || line.length() == 0) {
return null;
}
// trim leading AND trailing space
line = line.trim();
// check for comment and empty line
if (line.length() == 0 || line.startsWith("#")) {
return null;
}
// check line contains valid properties '=' separator
int indexOfEquals = line.indexOf('=');
if (indexOfEquals == -1) {
return null;
}
String key = line.substring(0, indexOfEquals);
String value = line.substring(indexOfEquals + 1, line.length());
return new String[] { key, value };
}
}