package org.jgroups.conf;
import org.w3c.dom.Element;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.jgroups.ChannelException;
import org.jgroups.JChannel;
import org.jgroups.util.Util;
import java.io.*;
import java.net.MalformedURLException;
import java.net.URL;
import java.util.Properties;
import java.util.HashMap;
import java.util.Map;
import java.util.Iterator;
import java.security.AccessControlException;
/**
* The ConfigurationFactory is a factory that returns a protocol stack configurator.
* The protocol stack configurator is an object that read a stack configuration and
* parses it so that the ProtocolStack can create a stack.
* <BR>
* Currently the factory returns one of the following objects:<BR>
* 1. XmlConfigurator - parses XML files<BR>
* 2. PlainConfigurator - uses the old style strings UDP:FRAG: etc etc<BR>
*
* @author Filip Hanik (<a href="mailto:filip@filip.net">filip@filip.net)
* @author Bela Ban
* @version $Id: ConfiguratorFactory.java,v 1.23 2007/06/06 11:02:35 belaban Exp $
*/
public class ConfiguratorFactory {
public static final String JAXP_MISSING_ERROR_MSG=
"JAXP Error: the required XML parsing classes are not available; " +
"make sure that JAXP compatible libraries are in the classpath.";
static final String FORCE_CONFIGURATION="force.properties";
static final Log log=LogFactory.getLog(ConfiguratorFactory.class);
static String propertiesOverride=null;
// Check for the presence of the system property "force.properties", and
// act appropriately if it is set. We only need to do this once since the
// system properties are highly unlikely to change.
static {
try {
Properties properties = System.getProperties();
propertiesOverride = properties.getProperty(FORCE_CONFIGURATION);
}
catch (SecurityException e) {
propertiesOverride = null;
}
if(propertiesOverride != null && log.isDebugEnabled()) {
log.debug("using properties override: " + propertiesOverride);
}
}
protected ConfiguratorFactory() {
}
/**
* Returns a protocol stack configurator based on the XML configuration
* provided by the specified File.
*
* @param file a File with a JGroups XML configuration.
*
* @return a <code>ProtocolStackConfigurator</code> containing the stack
* configuration.
*
* @throws ChannelException if problems occur during the configuration of
* the protocol stack.
*/
public static ProtocolStackConfigurator getStackConfigurator(File file) throws ChannelException {
ProtocolStackConfigurator returnValue;
if (propertiesOverride != null) {
returnValue = getStackConfigurator(propertiesOverride);
}
else {
try {
checkJAXPAvailability();
InputStream input=getConfigStream(file);
returnValue=XmlConfigurator.getInstance(input);
}
catch(Exception ex) {
throw createChannelConfigurationException(ex);
}
}
return returnValue;
}
/**
* Returns a protocol stack configurator based on the XML configuration
* provided at the specified URL.
*
* @param url a URL pointing to a JGroups XML configuration.
*
* @return a <code>ProtocolStackConfigurator</code> containing the stack
* configuration.
*
* @throws ChannelException if problems occur during the configuration of
* the protocol stack.
*/
public static ProtocolStackConfigurator getStackConfigurator(URL url) throws ChannelException {
ProtocolStackConfigurator returnValue;
if (propertiesOverride != null) {
returnValue = getStackConfigurator(propertiesOverride);
}
else {
checkForNullConfiguration(url);
checkJAXPAvailability();
try {
returnValue=XmlConfigurator.getInstance(url);
}
catch (IOException ioe) {
throw createChannelConfigurationException(ioe);
}
}
return returnValue;
}
/**
* Returns a protocol stack configurator based on the XML configuration
* provided by the specified XML element.
*
* @param element a XML element containing a JGroups XML configuration.
*
* @return a <code>ProtocolStackConfigurator</code> containing the stack
* configuration.
*
* @throws ChannelException if problems occur during the configuration of
* the protocol stack.
*/
public static ProtocolStackConfigurator getStackConfigurator(Element element) throws ChannelException {
ProtocolStackConfigurator returnValue;
if (propertiesOverride != null) {
returnValue = getStackConfigurator(propertiesOverride);
}
else {
checkForNullConfiguration(element);
// Since Element is a part of the JAXP specification and because an
// Element instance already exists, there is no need to check for
// JAXP availability.
//
// checkJAXPAvailability();
try {
returnValue=XmlConfigurator.getInstance(element);
}
catch (IOException ioe) {
throw createChannelConfigurationException(ioe);
}
}
return returnValue;
}
/**
* Returns a protocol stack configurator based on the provided properties
* string.
*
* @param properties an old style property string, a string representing a
* system resource containing a JGroups XML configuration,
* a string representing a URL pointing to a JGroups XML
* XML configuration, or a string representing a file name
* that contains a JGroups XML configuration.
*/
public static ProtocolStackConfigurator getStackConfigurator(String properties) throws ChannelException {
if (propertiesOverride != null) {
properties = propertiesOverride;
}
// added by bela: for null String props we use the default properties
if(properties == null)
properties=JChannel.DEFAULT_PROTOCOL_STACK;
checkForNullConfiguration(properties);
ProtocolStackConfigurator returnValue;
// Attempt to treat the properties string as a pointer to an XML
// configuration.
XmlConfigurator configurator = null;
try {
configurator=getXmlConfigurator(properties);
}
catch (IOException ioe) {
throw createChannelConfigurationException(ioe);
}
// Did the properties string point to a JGroups XML configuration?
if (configurator != null) {
returnValue=configurator;
}
else {
// Attempt to process the properties string as the old style
// property string.
returnValue=new PlainConfigurator(properties);
}
return returnValue;
}
/**
* Returns a protocol stack configurator based on the properties passed in.<BR>
* If the properties parameter is a plain string UDP:FRAG:MERGE:GMS etc, a PlainConfigurator is returned.<BR>
* If the properties parameter is a string that represents a url for example http://www.filip.net/test.xml
* or the parameter is a java.net.URL object, an XmlConfigurator is returned<BR>
*
* @param properties old style property string, url string, or java.net.URL object
* @return a ProtocolStackConfigurator containing the stack configuration
* @throws IOException if it fails to parse the XML content
* @throws IOException if the URL is invalid or a the content can not be reached
* @deprecated Used by the JChannel(Object) constructor which has been deprecated.
*/
public static ProtocolStackConfigurator getStackConfigurator(Object properties) throws IOException {
InputStream input=null;
if (propertiesOverride != null) {
properties = propertiesOverride;
}
// added by bela: for null String props we use the default properties
if(properties == null)
properties=JChannel.DEFAULT_PROTOCOL_STACK;
if(properties instanceof URL) {
try {
input=((URL)properties).openStream();
}
catch(Throwable t) {
}
}
// if it is a string, then it could be a plain string or a url
if(input == null && properties instanceof String) {
try {
input=new URL((String)properties).openStream();
}
catch(Exception ignore) {
// if we get here this means we don't have a URL
}
// another try - maybe it is a resource, e.g. udp.xml
if(input == null && ((String)properties).endsWith("xml")) {
try {
input=Util.getResourceAsStream((String)properties, ConfiguratorFactory.class);
}
catch(Throwable ignore) {
}
}
// try a regular file name
//
// This code was moved from the parent block (below) because of the
// possibility of causing a ClassCastException.
if(input == null) {
try {
input=new FileInputStream((String)properties);
}
catch(Throwable t) {
}
}
}
// try a regular file
if(input == null && properties instanceof File) {
try {
input=new FileInputStream((File)properties);
}
catch(Throwable t) {
}
}
if(input != null) {
return XmlConfigurator.getInstance(input);
}
if(properties instanceof Element) {
return XmlConfigurator.getInstance((Element)properties);
}
return new PlainConfigurator((String)properties);
}
public static InputStream getConfigStream(File file) throws Exception {
if(propertiesOverride != null)
return getConfigStream(propertiesOverride);
checkForNullConfiguration(file);
try {
return new FileInputStream(file);
}
catch(IOException ioe) {
throw createChannelConfigurationException(ioe);
}
}
public static InputStream getConfigStream(URL url) throws Exception {
if (propertiesOverride != null)
return getConfigStream(propertiesOverride);
try {
checkJAXPAvailability();
return url.openStream();
}
catch(Exception ex) {
throw createChannelConfigurationException(ex);
}
}
/**
* Returns a JGroups XML configuration InputStream based on the provided
* properties string.
*
* @param properties a string representing a system resource containing a
* JGroups XML configuration, a string representing a URL
* pointing to a JGroups ML configuration, or a string
* representing a file name that contains a JGroups XML
* configuration.
*
* @throws IOException if the provided properties string appears to be a
* valid URL but is unreachable.
*/
public static InputStream getConfigStream(String properties) throws IOException {
InputStream configStream = null;
if (propertiesOverride != null)
return getConfigStream(propertiesOverride);
// Check to see if the properties string is the name of a file.
try {
configStream=new FileInputStream(properties);
}
catch(FileNotFoundException fnfe) {
// the properties string is likely not a file
}
catch(AccessControlException access_ex) {
// fixes http://jira.jboss.com/jira/browse/JGRP-94
}
// Check to see if the properties string is a URL.
if(configStream == null) {
try {
configStream=new URL(properties).openStream();
}
catch (MalformedURLException mre) {
// the properties string is not a URL
}
}
// Commented so the caller is notified of this condition, but left in
// the code for documentation purposes.
//
// catch (IOException ioe) {
// the specified URL string was not reachable
// }
// Check to see if the properties string is the name of a resource,
// e.g. udp.xml.
if(configStream == null && properties.endsWith("xml")) {
configStream=Util.getResourceAsStream(properties, ConfiguratorFactory.class);
}
return configStream;
}
public static InputStream getConfigStream(Object properties) throws IOException {
InputStream input=null;
if (propertiesOverride != null)
return getConfigStream(propertiesOverride);
// added by bela: for null String props we use the default properties
if(properties == null)
properties=JChannel.DEFAULT_PROTOCOL_STACK;
if(properties instanceof URL) {
try {
input=((URL)properties).openStream();
}
catch(Throwable t) {
}
}
// if it is a string, then it could be a plain string or a url
if(input == null && properties instanceof String) {
input=getConfigStream((String)properties);
}
// try a regular file
if(input == null && properties instanceof File) {
try {
input=new FileInputStream((File)properties);
}
catch(Throwable t) {
}
}
if(input != null)
return input;
if(properties instanceof Element) {
return getConfigStream((Element)properties);
}
return new ByteArrayInputStream(((String)properties).getBytes());
}
/**
* Returns an XmlConfigurator based on the provided properties string (if
* possible).
*
* @param properties a string representing a system resource containing a
* JGroups XML configuration, a string representing a URL
* pointing to a JGroups ML configuration, or a string
* representing a file name that contains a JGroups XML
* configuration.
*
* @return an XmlConfigurator instance based on the provided properties
* string; <code>null</code> if the provided properties string does
* not point to an XML configuration.
*
* @throws IOException if the provided properties string appears to be a
* valid URL but is unreachable, or if the JGroups XML
* configuration pointed to by the URL can not be
* parsed.
*/
static XmlConfigurator getXmlConfigurator(String properties) throws IOException {
XmlConfigurator returnValue=null;
InputStream configStream=getConfigStream(properties);
if (configStream != null) {
checkJAXPAvailability();
returnValue=XmlConfigurator.getInstance(configStream);
}
return returnValue;
}
/**
* Creates a <code>ChannelException</code> instance based upon a
* configuration problem.
*
* @param cause the exceptional configuration condition to be used as the
* created <code>ChannelException</code>'s cause.
*/
static ChannelException createChannelConfigurationException(Throwable cause) {
return new ChannelException("unable to load the protocol stack", cause);
}
/**
* Check to see if the specified configuration properties are
* <code>null</null> which is not allowed.
*
* @param properties the specified protocol stack configuration.
*
* @throws NullPointerException if the specified configuration properties
* are <code>null</code>.
*/
static void checkForNullConfiguration(Object properties) {
if(properties == null)
throw new NullPointerException("the specifed protocol stack configuration was null");
}
/**
* Checks the availability of the JAXP classes on the classpath.
*
* @throws NoClassDefFoundError if the required JAXP classes are not
* availabile on the classpath.
*/
static void checkJAXPAvailability() {
try {
// TODO: Do some real class checking here instead of forcing the
// load of a JGroups class that happens (by default) to do it
// for us.
XmlConfigurator.class.getName();
}
catch (NoClassDefFoundError error) {
Error tmp=new NoClassDefFoundError(JAXP_MISSING_ERROR_MSG);
tmp.initCause(error);
throw tmp;
}
}
/** Replace variables of the form ${var:default} with the getProperty(var, default)
* @param configurator
*/
public static void substituteVariables(ProtocolStackConfigurator configurator) {
ProtocolData[] protocols;
try {
protocols=configurator.getProtocolStack();
}
catch(Exception e) {
protocols=null;
}
if(protocols == null)
return;
for(int i=0; i < protocols.length; i++) {
ProtocolData protocol=protocols[i];
if(protocol != null) {
HashMap parms=protocol.getParameters();
Map.Entry entry;
ProtocolParameter parm;
for(Iterator it=parms.entrySet().iterator(); it.hasNext();) {
entry=(Map.Entry)it.next();
parm=(ProtocolParameter)entry.getValue();
String val=parm.getValue();
String replacement=Util.substituteVariable(val);
if(!replacement.equals(val)) {
parm.setValue(replacement);
}
}
}
}
}
}