Author: veithen
Date: Mon Jul 27 18:00:30 2009
New Revision: 798240
URL: http://svn.apache.org/viewvc?rev=798240&view=rev
Log:
Some improvements of the StAX dialect detection:
* Avoid NPE if the StAX implementation is part of the JRE (in which case
getClassLoader may return null).
* Detect the StAX implementation on Sun's JRE 1.6.
* Fixed another potential NPE when the manifest file doesn't have all expected
attributes.
* Added more logging to warn the user if the StAX implementation can't be
detected.
Modified:
webservices/commons/trunk/modules/axiom/modules/axiom-api/src/main/java/org/apache/axiom/util/stax/dialect/StAXDialectDetector.java
Modified:
webservices/commons/trunk/modules/axiom/modules/axiom-api/src/main/java/org/apache/axiom/util/stax/dialect/StAXDialectDetector.java
URL:
http://svn.apache.org/viewvc/webservices/commons/trunk/modules/axiom/modules/axiom-api/src/main/java/org/apache/axiom/util/stax/dialect/StAXDialectDetector.java?rev=798240&r1=798239&r2=798240&view=diff
==============================================================================
---
webservices/commons/trunk/modules/axiom/modules/axiom-api/src/main/java/org/apache/axiom/util/stax/dialect/StAXDialectDetector.java
(original)
+++
webservices/commons/trunk/modules/axiom/modules/axiom-api/src/main/java/org/apache/axiom/util/stax/dialect/StAXDialectDetector.java
Mon Jul 27 18:00:30 2009
@@ -53,6 +53,14 @@
private static final Attributes.Name IMPLEMENTATION_VERSION =
new Attributes.Name("Implementation-Version");
+ /**
+ * Map that stores detected dialects by location. The location is the URL
corresponding to the
+ * root folder of the classpath entry from which the StAX implementation
is loaded. Note that
+ * in the case of a JAR file, this is not the URL pointing to the JAR, but
a <tt>jar:</tt>
+ * URL that points to the root folder of the archive. The
<code>null</code> location is used
+ * to represent StAX implementations that are loaded from the bootstrap
class loader, i.e.
+ * which are part of the JRE.
+ */
private static final Map/*<URL,StAXDialect>*/ dialectByUrl =
Collections.synchronizedMap(new HashMap());
@@ -119,15 +127,21 @@
* @return the detected dialect
*/
public static StAXDialect getDialect(Class implementationClass) {
- URL rootUrl =
getRootUrlForResource(implementationClass.getClassLoader(),
- implementationClass.getName().replace('.', '/') + ".class");
- if (rootUrl == null) {
- log.warn("Unable to determine location of StAX implementation
containing class "
- + implementationClass.getName() + "; using default
dialect");
- return UnknownStAXDialect.INSTANCE;
+ URL rootUrl;
+ ClassLoader classLoader = implementationClass.getClassLoader();
+ if (classLoader == null) {
+ // null means bootstrap classloader; represent this location as
null
+ rootUrl = null;
} else {
- return getDialect(rootUrl);
+ rootUrl = getRootUrlForResource(classLoader,
+ implementationClass.getName().replace('.', '/') +
".class");
+ if (rootUrl == null) {
+ log.warn("Unable to determine location of StAX implementation
containing class "
+ + implementationClass.getName() + "; using default
dialect");
+ return UnknownStAXDialect.INSTANCE;
+ }
}
+ return getDialect(rootUrl);
}
private static StAXDialect getDialect(URL rootUrl) {
@@ -142,6 +156,35 @@
}
private static StAXDialect detectDialect(URL rootUrl) {
+ StAXDialect dialect;
+ if (rootUrl == null) {
+ dialect = detectDialectFromJRE();
+ } else {
+ dialect = detectDialectFromJar(rootUrl);
+ }
+ if (log.isInfoEnabled()) {
+ log.info("Detected StAX dialect: " + dialect.getName());
+ }
+ return dialect;
+ }
+
+ private static StAXDialect detectDialectFromJRE() {
+ String vendor = System.getProperty("java.vendor");
+ String version = System.getProperty("java.version");
+ if (log.isDebugEnabled()) {
+ log.debug("StAX implementation is part of the JRE:\n" +
+ " Vendor: " + vendor + "\n" +
+ " Version: " + version);
+ }
+ if (vendor.startsWith("Sun") || vendor.startsWith("Apple")) {
+ return SJSXPDialect.INSTANCE;
+ } else {
+ log.warn("Unable to determine dialect of StAX implementation
provided by the JRE");
+ return UnknownStAXDialect.INSTANCE;
+ }
+ }
+
+ private static StAXDialect detectDialectFromJar(URL rootUrl) {
Manifest manifest;
try {
URL metaInfUrl = new URL(rootUrl, "META-INF/MANIFEST.MF");
@@ -167,13 +210,14 @@
}
// For the moment, the dialect detection is quite simple, but in the
future we will probably
// have to differentiate by version number
- if(vendor != null) {
- if (vendor.toLowerCase().indexOf("woodstox") != -1) {
- return WoodstoxDialect.INSTANCE;
- } else if (title.indexOf("SJSXP") != -1) {
- return SJSXPDialect.INSTANCE;
- }
+ if (vendor != null && vendor.toLowerCase().indexOf("woodstox") != -1) {
+ return WoodstoxDialect.INSTANCE;
+ } else if (title != null && title.indexOf("SJSXP") != -1) {
+ return SJSXPDialect.INSTANCE;
+ } else {
+ log.warn("Unable to determine dialect of the StAX implementation
at " + rootUrl
+ + " (using JAR manifest)");
+ return UnknownStAXDialect.INSTANCE;
}
- return UnknownStAXDialect.INSTANCE;
}
}
