in javax-el-api-3.0.2/src/main/java/javax/el/FactoryFinder.java [130:213]
static Object find(String factoryId, String fallbackClassName,
Properties properties)
{
try {
// If we are deployed into an OSGi environment, leverage it
Class factoryClass = null;
try {
factoryClass = FactoryFinder.class.getClassLoader().loadClass(factoryId);
} catch (Throwable t) {
throw t;
}
Class spiClass = org.apache.servicemix.specs.locator.OsgiLocator.locate(factoryClass, factoryId);
if (spiClass != null) {
return spiClass.newInstance();
}
} catch (Throwable e) {
}
ClassLoader classLoader;
try {
classLoader = Thread.currentThread().getContextClassLoader();
} catch (Exception x) {
throw new ELException(x.toString(), x);
}
String serviceId = "META-INF/services/" + factoryId;
// try to find services in CLASSPATH
try {
InputStream is=null;
if (classLoader == null) {
is=ClassLoader.getSystemResourceAsStream(serviceId);
} else {
is=classLoader.getResourceAsStream(serviceId);
}
if( is!=null ) {
BufferedReader rd =
new BufferedReader(new InputStreamReader(is, "UTF-8"));
String factoryClassName = rd.readLine();
rd.close();
if (factoryClassName != null &&
! "".equals(factoryClassName)) {
return newInstance(factoryClassName, classLoader, properties);
}
}
} catch( Exception ex ) {
}
// try to read from $java.home/lib/el.properties
try {
String javah=System.getProperty( "java.home" );
String configFile = javah + File.separator +
"lib" + File.separator + "el.properties";
File f=new File( configFile );
if( f.exists()) {
Properties props=new Properties();
props.load( new FileInputStream(f));
String factoryClassName = props.getProperty(factoryId);
return newInstance(factoryClassName, classLoader, properties);
}
} catch(Exception ex ) {
}
// Use the system property
try {
String systemProp =
System.getProperty( factoryId );
if( systemProp!=null) {
return newInstance(systemProp, classLoader, properties);
}
} catch (SecurityException se) {
}
if (fallbackClassName == null) {
throw new ELException(
"Provider for " + factoryId + " cannot be found", null);
}
return newInstance(fallbackClassName, classLoader, properties);
}