org.xml.sax.helpers
class: NewInstance [javadoc |
source]
java.lang.Object
org.xml.sax.helpers.NewInstance
Create a new instance of a class by name.
This module, both source code and documentation, is in the
Public Domain, and comes with NO WARRANTY.
See http://www.saxproject.org
for further information.
This class contains a static method for creating an instance of a
class from an explicit class name. It tries to use the thread's context
ClassLoader if possible and falls back to using
Class.forName(String). It also takes into account JDK 1.2+'s
AccessController mechanism for performing its actions.
This code is designed to compile and run on JDK version 1.1 and later
including versions of Java 2.
This is not the NewInstance accompanying SAX 2.0.2; it
represents many fixes to that code.
- author:
Edwin - Goei, David Brownell
- version:
2.0.1 - (sax2r2)
| Methods from java.lang.Object: |
|---|
|
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait |
| Method from org.xml.sax.helpers.NewInstance Detail: |
|---|
 static ClassLoader getClassLoader() {
// Figure out which ClassLoader to use for loading the provider
// class. If there is a Context ClassLoader then use it.
ClassLoader cl = SecuritySupport.getContextClassLoader();
if (cl == null) {
// Assert: we are on JDK 1.1 or we have no Context ClassLoader
// so use the current ClassLoader
cl = NewInstance.class.getClassLoader();
}
return cl;
}
Figure out which ClassLoader to use. For JDK 1.2 and later use
the context ClassLoader. |
static Object newInstance(ClassLoader classLoader,
String className) throws ClassNotFoundException, IllegalAccessException, InstantiationException {
Class driverClass;
if (classLoader == null) {
// XXX Use the bootstrap ClassLoader. There is no way to
// load a class using the bootstrap ClassLoader that works
// in both JDK 1.1 and Java 2. However, this should still
// work b/c the following should be true:
//
// (cl == null) iff current ClassLoader == null
//
// Thus Class.forName(String) will use the current
// ClassLoader which will be the bootstrap ClassLoader.
driverClass = Class.forName(className);
} else {
try {
driverClass = classLoader.loadClass(className);
} catch (ClassNotFoundException x) {
if (DO_FALLBACK) {
// Fall back to current classloader
classLoader = NewInstance.class.getClassLoader();
if (classLoader != null) {
driverClass = classLoader.loadClass(className);
}
else {
driverClass = Class.forName(className);
}
} else {
throw x;
}
}
}
Object instance = driverClass.newInstance();
return instance;
} Creates a new instance of the specified class name
Package private so this code is not exposed at the API level. |