src/javax/xml/stream/FactoryFinder.java
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rev 406 : 8005954: JAXP Plugability Layer should use java.util.ServiceLoader
Summary: This fix replaces manual processing of files under META-INF/services in JAXP factories by calls to java.util.ServiceLoader.
Reviewed-by: alanb, joehw, mchung
*** 1,7 ****
/*
! * Copyright (c) 2005, 2006, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation. Oracle designates this
--- 1,7 ----
/*
! * Copyright (c) 2005, 2013, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation. Oracle designates this
*** 23,41 ****
* questions.
*/
package javax.xml.stream;
- import java.io.BufferedReader;
import java.io.File;
! import java.io.IOException;
! import java.io.InputStream;
! import java.io.InputStreamReader;
import java.util.Properties;
/**
! * <p>Implements pluggable Datatypes.</p>
*
* <p>This class is duplicated for each JAXP subpackage so keep it in
* sync. It is package private for secure class loading.</p>
*
* @author Santiago.PericasGeertsen@sun.com
--- 23,42 ----
* questions.
*/
package javax.xml.stream;
import java.io.File;
! import java.security.AccessController;
! import java.security.PrivilegedAction;
! import java.util.Iterator;
import java.util.Properties;
+ import java.util.ServiceConfigurationError;
+ import java.util.ServiceLoader;
/**
! * <p>Implements pluggable streams.</p>
*
* <p>This class is duplicated for each JAXP subpackage so keep it in
* sync. It is package private for secure class loading.</p>
*
* @author Santiago.PericasGeertsen@sun.com
*** 50,72 ****
private static boolean debug = false;
/**
* Cache for properties in java.home/lib/jaxp.properties
*/
! static Properties cacheProps = new Properties();
/**
* Flag indicating if properties from java.home/lib/jaxp.properties
* have been cached.
*/
! static volatile boolean firstTime = true;
/**
* Security support class use to check access control before
* getting certain system resources.
*/
! static SecuritySupport ss = new SecuritySupport();
// Define system property "jaxp.debug" to get output
static {
// Use try/catch block to support applets, which throws
// SecurityException out of this code.
--- 51,73 ----
private static boolean debug = false;
/**
* Cache for properties in java.home/lib/jaxp.properties
*/
! final private static Properties cacheProps = new Properties();
/**
* Flag indicating if properties from java.home/lib/jaxp.properties
* have been cached.
*/
! private static volatile boolean firstTime = true;
/**
* Security support class use to check access control before
* getting certain system resources.
*/
! final private static SecuritySupport ss = new SecuritySupport();
// Define system property "jaxp.debug" to get output
static {
// Use try/catch block to support applets, which throws
// SecurityException out of this code.
*** 101,129 ****
boolean doFallback, boolean useBSClsLoader) throws ClassNotFoundException
{
try {
if (cl == null) {
if (useBSClsLoader) {
! return Class.forName(className, true, FactoryFinder.class.getClassLoader());
} else {
cl = ss.getContextClassLoader();
if (cl == null) {
throw new ClassNotFoundException();
}
else {
! return cl.loadClass(className);
}
}
}
else {
! return cl.loadClass(className);
}
}
catch (ClassNotFoundException e1) {
if (doFallback) {
// Use current class loader - should always be bootstrap CL
! return Class.forName(className, true, FactoryFinder.class.getClassLoader());
}
else {
throw e1;
}
}
--- 102,130 ----
boolean doFallback, boolean useBSClsLoader) throws ClassNotFoundException
{
try {
if (cl == null) {
if (useBSClsLoader) {
! return Class.forName(className, false, FactoryFinder.class.getClassLoader());
} else {
cl = ss.getContextClassLoader();
if (cl == null) {
throw new ClassNotFoundException();
}
else {
! return Class.forName(className, false, cl);
}
}
}
else {
! return Class.forName(className, false, cl);
}
}
catch (ClassNotFoundException e1) {
if (doFallback) {
// Use current class loader - should always be bootstrap CL
! return Class.forName(className, false, FactoryFinder.class.getClassLoader());
}
else {
throw e1;
}
}
*** 131,159 ****
/**
* Create an instance of a class. Delegates to method
* <code>getProviderClass()</code> in order to load the class.
*
* @param className Name of the concrete class corresponding to the
* service provider
*
* @param cl <code>ClassLoader</code> used to load the factory class. If <code>null</code>
* current <code>Thread</code>'s context classLoader is used to load the factory class.
*
* @param doFallback True if the current ClassLoader should be tried as
* a fallback if the class is not found using cl
*/
! static Object newInstance(String className, ClassLoader cl, boolean doFallback)
! throws ConfigurationError
{
! return newInstance(className, cl, doFallback, false);
}
/**
* Create an instance of a class. Delegates to method
* <code>getProviderClass()</code> in order to load the class.
*
* @param className Name of the concrete class corresponding to the
* service provider
*
* @param cl <code>ClassLoader</code> used to load the factory class. If <code>null</code>
* current <code>Thread</code>'s context classLoader is used to load the factory class.
--- 132,166 ----
/**
* Create an instance of a class. Delegates to method
* <code>getProviderClass()</code> in order to load the class.
*
+ * @param type Base class / Service interface of the factory to
+ * instantiate.
+ *
* @param className Name of the concrete class corresponding to the
* service provider
*
* @param cl <code>ClassLoader</code> used to load the factory class. If <code>null</code>
* current <code>Thread</code>'s context classLoader is used to load the factory class.
*
* @param doFallback True if the current ClassLoader should be tried as
* a fallback if the class is not found using cl
*/
! static <T> T newInstance(Class<T> type, String className, ClassLoader cl, boolean doFallback)
! throws FactoryConfigurationError
{
! return newInstance(type, className, cl, doFallback, false);
}
/**
* Create an instance of a class. Delegates to method
* <code>getProviderClass()</code> in order to load the class.
*
+ * @param type Base class / Service interface of the factory to
+ * instantiate.
+ *
* @param className Name of the concrete class corresponding to the
* service provider
*
* @param cl <code>ClassLoader</code> used to load the factory class. If <code>null</code>
* current <code>Thread</code>'s context classLoader is used to load the factory class.
*** 162,225 ****
* a fallback if the class is not found using cl
*
* @param useBSClsLoader True if cl=null actually meant bootstrap classLoader. This parameter
* is needed since DocumentBuilderFactory/SAXParserFactory defined null as context classLoader.
*/
! static Object newInstance(String className, ClassLoader cl, boolean doFallback, boolean useBSClsLoader)
! throws ConfigurationError
{
// make sure we have access to restricted packages
if (System.getSecurityManager() != null) {
if (className != null && className.startsWith(DEFAULT_PACKAGE)) {
cl = null;
useBSClsLoader = true;
}
}
try {
! Class providerClass = getProviderClass(className, cl, doFallback, useBSClsLoader);
Object instance = providerClass.newInstance();
if (debug) { // Extra check to avoid computing cl strings
dPrint("created new instance of " + providerClass +
" using ClassLoader: " + cl);
}
! return instance;
}
catch (ClassNotFoundException x) {
! throw new ConfigurationError(
"Provider " + className + " not found", x);
}
catch (Exception x) {
! throw new ConfigurationError(
"Provider " + className + " could not be instantiated: " + x,
x);
}
}
/**
* Finds the implementation Class object in the specified order.
*
* @return Class object of factory, never null
*
! * @param factoryId Name of the factory to find, same as
! * a property name
* @param fallbackClassName Implementation class name, if nothing else
* is found. Use null to mean no fallback.
*
* Package private so this code can be shared.
*/
! static Object find(String factoryId, String fallbackClassName)
! throws ConfigurationError
{
! return find(factoryId, null, fallbackClassName);
}
/**
* Finds the implementation Class object in the specified order. Main
* entry point.
* @return Class object of factory, never null
*
* @param factoryId Name of the factory to find, same as
* a property name
*
* @param cl ClassLoader to be used to load the class, null means to use
* the bootstrap ClassLoader
--- 169,242 ----
* a fallback if the class is not found using cl
*
* @param useBSClsLoader True if cl=null actually meant bootstrap classLoader. This parameter
* is needed since DocumentBuilderFactory/SAXParserFactory defined null as context classLoader.
*/
! static <T> T newInstance(Class<T> type, String className, ClassLoader cl,
! boolean doFallback, boolean useBSClsLoader)
! throws FactoryConfigurationError
{
+ assert type != null;
+
// make sure we have access to restricted packages
if (System.getSecurityManager() != null) {
if (className != null && className.startsWith(DEFAULT_PACKAGE)) {
cl = null;
useBSClsLoader = true;
}
}
try {
! Class<?> providerClass = getProviderClass(className, cl, doFallback, useBSClsLoader);
! if (!type.isAssignableFrom(providerClass)) {
! throw new ClassCastException(className + " cannot be cast to " + type.getName());
! }
Object instance = providerClass.newInstance();
if (debug) { // Extra check to avoid computing cl strings
dPrint("created new instance of " + providerClass +
" using ClassLoader: " + cl);
}
! return type.cast(instance);
}
catch (ClassNotFoundException x) {
! throw new FactoryConfigurationError(
"Provider " + className + " not found", x);
}
catch (Exception x) {
! throw new FactoryConfigurationError(
"Provider " + className + " could not be instantiated: " + x,
x);
}
}
/**
* Finds the implementation Class object in the specified order.
*
* @return Class object of factory, never null
*
! * @param type Base class / Service interface of the
! * factory to find.
! *
* @param fallbackClassName Implementation class name, if nothing else
* is found. Use null to mean no fallback.
*
* Package private so this code can be shared.
*/
! static <T> T find(Class<T> type, String fallbackClassName)
! throws FactoryConfigurationError
{
! return find(type, type.getName(), null, fallbackClassName);
}
/**
* Finds the implementation Class object in the specified order. Main
* entry point.
* @return Class object of factory, never null
*
+ * @param type Base class / Service interface of the
+ * factory to find.
+ *
* @param factoryId Name of the factory to find, same as
* a property name
*
* @param cl ClassLoader to be used to load the class, null means to use
* the bootstrap ClassLoader
*** 227,258 ****
* @param fallbackClassName Implementation class name, if nothing else
* is found. Use null to mean no fallback.
*
* Package private so this code can be shared.
*/
! static Object find(String factoryId, ClassLoader cl, String fallbackClassName)
! throws ConfigurationError
{
dPrint("find factoryId =" + factoryId);
// Use the system property first
try {
String systemProp = ss.getSystemProperty(factoryId);
if (systemProp != null) {
dPrint("found system property, value=" + systemProp);
! return newInstance(systemProp, null, true);
}
}
catch (SecurityException se) {
if (debug) se.printStackTrace();
}
// Try read $java.home/lib/stax.properties followed by
// $java.home/lib/jaxp.properties if former not present
String configFile = null;
try {
- String factoryClassName = null;
if (firstTime) {
synchronized (cacheProps) {
if (firstTime) {
configFile = ss.getSystemProperty("java.home") + File.separator +
"lib" + File.separator + "stax.properties";
--- 244,276 ----
* @param fallbackClassName Implementation class name, if nothing else
* is found. Use null to mean no fallback.
*
* Package private so this code can be shared.
*/
! static <T> T find(Class<T> type, String factoryId, ClassLoader cl, String fallbackClassName)
! throws FactoryConfigurationError
{
dPrint("find factoryId =" + factoryId);
// Use the system property first
try {
String systemProp = ss.getSystemProperty(factoryId);
if (systemProp != null) {
dPrint("found system property, value=" + systemProp);
! // There's a bug here - because 'cl' is ignored.
! // This will be handled separately.
! return newInstance(type, systemProp, null, true);
}
}
catch (SecurityException se) {
if (debug) se.printStackTrace();
}
// Try read $java.home/lib/stax.properties followed by
// $java.home/lib/jaxp.properties if former not present
String configFile = null;
try {
if (firstTime) {
synchronized (cacheProps) {
if (firstTime) {
configFile = ss.getSystemProperty("java.home") + File.separator +
"lib" + File.separator + "stax.properties";
*** 272,398 ****
}
}
}
}
}
! factoryClassName = cacheProps.getProperty(factoryId);
if (factoryClassName != null) {
dPrint("found in " + configFile + " value=" + factoryClassName);
! return newInstance(factoryClassName, null, true);
}
}
catch (Exception ex) {
if (debug) ex.printStackTrace();
}
// Try Jar Service Provider Mechanism
! Object provider = findJarServiceProvider(factoryId);
if (provider != null) {
return provider;
}
if (fallbackClassName == null) {
! throw new ConfigurationError(
"Provider for " + factoryId + " cannot be found", null);
}
dPrint("loaded from fallback value: " + fallbackClassName);
! return newInstance(fallbackClassName, cl, true);
}
/*
! * Try to find provider using Jar Service Provider Mechanism
*
* @return instance of provider class if found or null
*/
! private static Object findJarServiceProvider(String factoryId)
! throws ConfigurationError
! {
! String serviceId = "META-INF/services/" + factoryId;
! InputStream is = null;
!
! // First try the Context ClassLoader
! ClassLoader cl = ss.getContextClassLoader();
! boolean useBSClsLoader = false;
! if (cl != null) {
! is = ss.getResourceAsStream(cl, serviceId);
!
! // If no provider found then try the current ClassLoader
! if (is == null) {
! cl = FactoryFinder.class.getClassLoader();
! is = ss.getResourceAsStream(cl, serviceId);
! useBSClsLoader = true;
! }
! } else {
! // No Context ClassLoader, try the current ClassLoader
! cl = FactoryFinder.class.getClassLoader();
! is = ss.getResourceAsStream(cl, serviceId);
! useBSClsLoader = true;
! }
!
! if (is == null) {
! // No provider found
! return null;
! }
!
! if (debug) { // Extra check to avoid computing cl strings
! dPrint("found jar resource=" + serviceId + " using ClassLoader: " + cl);
! }
!
! BufferedReader rd;
! try {
! rd = new BufferedReader(new InputStreamReader(is, "UTF-8"));
! }
! catch (java.io.UnsupportedEncodingException e) {
! rd = new BufferedReader(new InputStreamReader(is));
! }
!
! String factoryClassName = null;
try {
! // XXX Does not handle all possible input as specified by the
! // Jar Service Provider specification
! factoryClassName = rd.readLine();
! rd.close();
! } catch (IOException x) {
! // No provider found
! return null;
! }
!
! if (factoryClassName != null && !"".equals(factoryClassName)) {
! dPrint("found in resource, value=" + factoryClassName);
!
! // Note: here we do not want to fall back to the current
! // ClassLoader because we want to avoid the case where the
! // resource file was found using one ClassLoader and the
! // provider class was instantiated using a different one.
! return newInstance(factoryClassName, cl, false, useBSClsLoader);
! }
!
! // No provider found
return null;
}
-
- static class ConfigurationError extends Error {
- private Exception exception;
-
- /**
- * Construct a new instance with the specified detail string and
- * exception.
- */
- ConfigurationError(String msg, Exception x) {
- super(msg);
- this.exception = x;
}
!
! Exception getException() {
! return exception;
! }
! /**
! * use the exception chaining mechanism of JDK1.4
! */
! @Override
! public Throwable getCause() {
! return exception;
}
}
}
--- 290,366 ----
}
}
}
}
}
! final String factoryClassName = cacheProps.getProperty(factoryId);
if (factoryClassName != null) {
dPrint("found in " + configFile + " value=" + factoryClassName);
! // There's a bug here - because 'cl' is ignored.
! // This will be handled separately.
! return newInstance(type, factoryClassName, null, true);
}
}
catch (Exception ex) {
if (debug) ex.printStackTrace();
}
+ if (type.getName().equals(factoryId)) {
// Try Jar Service Provider Mechanism
! final T provider = findServiceProvider(type);
if (provider != null) {
return provider;
}
+ } else {
+ // We're in the case where a 'custom' factoryId was provided,
+ // and in every case where that happens, we expect that
+ // fallbackClassName will be null.
+ assert fallbackClassName == null;
+ }
if (fallbackClassName == null) {
! throw new FactoryConfigurationError(
"Provider for " + factoryId + " cannot be found", null);
}
dPrint("loaded from fallback value: " + fallbackClassName);
! return newInstance(type, fallbackClassName, cl, true);
}
/*
! * Try to find provider using the ServiceLoader API
! *
! * @param type Base class / Service interface of the factory to find.
*
* @return instance of provider class if found or null
*/
! private static <T> T findServiceProvider(final Class<T> type) {
try {
! return AccessController.doPrivileged(new PrivilegedAction<T>() {
! @Override
! public T run() {
! final ServiceLoader<T> serviceLoader = ServiceLoader.load(type);
! final Iterator<T> iterator = serviceLoader.iterator();
! if (iterator.hasNext()) {
! return iterator.next();
! } else {
return null;
}
}
! });
! } catch(ServiceConfigurationError e) {
! // It is not possible to wrap an error directly in
! // FactoryConfigurationError - so we need to wrap the
! // ServiceConfigurationError in a RuntimeException.
! // The alternative would be to modify the logic in
! // FactoryConfigurationError to allow setting a
! // Throwable as the cause, but that could cause
! // compatibility issues down the road.
! final RuntimeException x = new RuntimeException(
! "Provider for " + type + " cannot be created", e);
! final FactoryConfigurationError error =
! new FactoryConfigurationError(x, x.getMessage());
! throw error;
}
}
}