package org.jgroups.conf;
import org.jgroups.JChannel;
import org.jgroups.util.Util;
import org.w3c.dom.Element;
import java.io.*;
import java.net.MalformedURLException;
import java.net.URL;
import java.security.AccessControlException;
import java.util.List;
import java.util.Map;
/**
* 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
*/
public class ConfiguratorFactory {
public static final String JAXP_MISSING_ERROR_MSG="the required XML parsing classes are not available; " +
"make sure that JAXP compatible libraries are in the classpath.";
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 Exception if problems occur during the configuration of the protocol stack.
*/
public static ProtocolStackConfigurator getStackConfigurator(File file) throws Exception {
checkJAXPAvailability();
InputStream input=getConfigStream(file);
return XmlConfigurator.getInstance(input);
}
public static ProtocolStackConfigurator getStackConfigurator(InputStream input) throws Exception {
return XmlConfigurator.getInstance(input);
}
/**
* 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 Exception if problems occur during the configuration of the protocol stack.
*/
public static ProtocolStackConfigurator getStackConfigurator(URL url) throws Exception {
checkForNullConfiguration(url);
checkJAXPAvailability();
return XmlConfigurator.getInstance(url);
}
/**
* 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 Exception if problems occur during the configuration of the protocol stack.
*/
public static ProtocolStackConfigurator getStackConfigurator(Element element) throws Exception {
checkForNullConfiguration(element);
return XmlConfigurator.getInstance(element);
}
/**
* 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 configuration,
* or a string representing a file name that contains a JGroups XML configuration.
*/
public static ProtocolStackConfigurator getStackConfigurator(String properties) throws Exception {
// added by bela: for null String props we use the default properties
if(properties == null)
properties=JChannel.DEFAULT_PROTOCOL_STACK;
// Attempt to treat the properties string as a pointer to an XML configuration.
XmlConfigurator configurator = null;
checkForNullConfiguration(properties);
configurator=getXmlConfigurator(properties);
if (configurator != null) // did the properties string point to a JGroups XML configuration ?
return configurator;
else
return new PlainConfigurator(properties); // try to process the properties string as an old style property string
}
public static InputStream getConfigStream(File file) throws Exception {
checkForNullConfiguration(file);
return new FileInputStream(file);
}
public static InputStream getConfigStream(URL url) throws Exception {
checkJAXPAvailability();
return url.openStream();
}
/**
* 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;
// 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
}
}
// 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;
// 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(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 && properties.endsWith(".xml"))
throw new FileNotFoundException(Util.getMessage("FileNotFound", properties));
if (configStream != null) {
checkJAXPAvailability();
returnValue=XmlConfigurator.getInstance(configStream);
}
return returnValue;
}
/**
* 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 {
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) {
List<ProtocolConfiguration> protocols=configurator.getProtocolStack();
for(ProtocolConfiguration data: protocols) {
if(data != null) {
Map<String,String> parms=data.getProperties();
for(Map.Entry<String,String> entry:parms.entrySet()) {
String val=entry.getValue();
String replacement=Util.substituteVariable(val);
if(!replacement.equals(val)) {
entry.setValue(replacement);
}
}
}
}
}
}