package org.jboss.resteasy.spi;
import java.io.BufferedReader;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.security.AccessController;
import java.security.PrivilegedAction;
import java.security.PrivilegedActionException;
import java.security.PrivilegedExceptionAction;
import java.util.Properties;
import java.util.logging.Level;
import java.util.logging.Logger;
final class FactoryFinder {
private static final Logger LOGGER = Logger.getLogger(FactoryFinder.class.getName());
private static final String RESTEASY_JAXRS_API_MODULE = "org.jboss.resteasy.resteasy-jaxrs-api";
private FactoryFinder() {
// prevents instantiation
}
static ClassLoader getContextClassLoader() {
return AccessController.doPrivileged(
new PrivilegedAction<ClassLoader>() {
@Override
public ClassLoader run() {
ClassLoader cl = null;
try {
cl = Thread.currentThread().getContextClassLoader();
} catch (SecurityException ex) {
LOGGER.log(
Level.WARNING,
"Unable to get context classloader instance.",
ex);
}
return cl;
}
});
}
/**
* Creates an instance of the specified class using the specified
* {@code ClassLoader} object.
*
* @param className name of the class to be instantiated.
* @param classLoader class loader to be used.
* @return instance of the specified class.
* @throws ClassNotFoundException if the given class could not be found
* or could not be instantiated.
*/
private static Object newInstance(final String className,
final ClassLoader classLoader) throws ClassNotFoundException {
try {
Class spiClass;
if (classLoader == null) {
spiClass = Class.forName(className);
} else {
try {
spiClass = Class.forName(className, false, classLoader);
} catch (ClassNotFoundException ex) {
LOGGER.log(
Level.FINE,
"Unable to load provider class " + className
+ " using custom classloader " + classLoader.getClass().getName()
+ " trying again with current classloader.",
ex);
spiClass = Class.forName(className);
}
}
return spiClass.newInstance();
} catch (ClassNotFoundException x) {
throw x;
} catch (Exception x) {
throw new ClassNotFoundException("Provider " + className + " could not be instantiated: " + x, x);
}
}
/**
* Finds the implementation {@code Class} object for the given
* factory name, or if that fails, finds the {@code Class} object
* for the given fallback class name. The arguments supplied MUST be
* used in order. If using the first argument is successful, the second
* one will not be used.
* <p>
* This method is package private so that this code can be shared.
* </p>
*
* @param factoryId the name of the factory to find, which is
* a system property.
* @param fallbackClassName the implementation class name, which is
* to be used only if nothing else.
* is found; {@code null} to indicate that
* there is no fallback class name.
* @return the {@code Class} object of the specified message factory;
* may not be {@code null}.
* @throws ClassNotFoundException if there is an error.
*/
static Object find(final String factoryId, final String fallbackClassName) throws ClassNotFoundException {
ClassLoader classLoader = getContextClassLoader();
String serviceId = "META-INF/services/" + factoryId;
BufferedReader rd = null;
InputStream is = null;
// try to find services in CLASSPATH
try {
if (classLoader == null) {
is = ClassLoader.getSystemResourceAsStream(serviceId);
} else {
is = classLoader.getResourceAsStream(serviceId);
}
if (is != null) {
rd = new BufferedReader(new InputStreamReader(is, "UTF-8"));
String factoryClassName = rd.readLine();
if (factoryClassName != null && !"".equals(factoryClassName)) {
return newInstance(factoryClassName, classLoader);
}
}
} catch (Exception ex) {
LOGGER.log(Level.FINER, "Failed to load service " + factoryId + " from " + serviceId, ex);
} finally {
try {
if (rd != null)
rd.close();
if (is != null)
is.close();
} catch (IOException ex) {
LOGGER.log(Level.FINER, "Failed to close BufferedReader/InputStream.", ex);
}
}
FileInputStream fis = null;
// try to read from $java.home/lib/jaxrs.properties
try {
String javah = System.getProperty("java.home");
String configFile = javah + File.separator
+ "lib" + File.separator + "jaxrs.properties";
File f = new File(configFile);
if (f.exists()) {
Properties props = new Properties();
fis = new FileInputStream(f);
props.load(fis);
String factoryClassName = props.getProperty(factoryId);
return newInstance(factoryClassName, classLoader);
}
} catch (Exception ex) {
LOGGER.log(Level.FINER, "Failed to load service " + factoryId
+ " from $java.home/lib/jaxrs.properties", ex);
} finally {
try {
if (fis != null)
fis.close();
} catch (IOException ex) {
LOGGER.log(Level.FINER, "Failed to close FileInputStream.", ex);
}
}
// Use the system property
try {
String systemProp = System.getProperty(factoryId);
if (systemProp != null) {
return newInstance(systemProp, classLoader);
}
} catch (SecurityException se) {
LOGGER.log(Level.FINER, "Failed to load service " + factoryId
+ " from a system property", se);
}
ClassLoader moduleClassLoader = getModuleClassLoader();
rd = null;
is = null;
if (moduleClassLoader != null) {
try {
is = moduleClassLoader.getResourceAsStream(serviceId);
if( is!=null ) {
rd = new BufferedReader(new InputStreamReader(is, "UTF-8"));
String factoryClassName = rd.readLine();
if (factoryClassName != null &&
! "".equals(factoryClassName)) {
return newInstance(factoryClassName, moduleClassLoader);
}
}
} catch( Exception ex ) {
} finally {
try {
if (rd != null)
rd.close();
if (is != null)
is.close();
} catch (IOException ex) {
LOGGER.log(Level.FINER, "Failed to close BufferedReader/InputStream.", ex);
}
}
}
if (fallbackClassName == null) {
throw new ClassNotFoundException(
"Provider for " + factoryId + " cannot be found", null);
}
return newInstance(fallbackClassName, classLoader);
}
private static ClassLoader getModuleClassLoader() {
try {
final Class<?> moduleClass = Class.forName("org.jboss.modules.Module");
final Class<?> moduleIdentifierClass = Class.forName("org.jboss.modules.ModuleIdentifier");
final Class<?> moduleLoaderClass = Class.forName("org.jboss.modules.ModuleLoader");
final Object moduleLoader;
final SecurityManager sm = System.getSecurityManager();
if (sm == null) {
moduleLoader = moduleClass.getMethod("getBootModuleLoader").invoke(null);
} else {
try {
moduleLoader = AccessController.doPrivileged(new PrivilegedExceptionAction<Object>() {
public Object run() throws Exception {
return moduleClass.getMethod("getBootModuleLoader").invoke(null);
}
});
} catch (PrivilegedActionException pae) {
throw pae.getException();
}
}
Object moduleIdentifier = moduleIdentifierClass.getMethod("create", String.class).invoke(null, RESTEASY_JAXRS_API_MODULE);
Object module = moduleLoaderClass.getMethod("loadModule", moduleIdentifierClass).invoke(moduleLoader, moduleIdentifier);
return (ClassLoader)moduleClass.getMethod("getClassLoader").invoke(module);
} catch (ClassNotFoundException e) {
//ignore, JBoss Modules might not be available at all
return null;
} catch (RuntimeException e) {
throw e;
} catch (Exception e) {
throw new RuntimeException(e);
}
}
}