HADOOP-13400. Update the ApplicationClassLoader implementation in line with latest Java ClassLoader implementation. Contributed by Vrushali C.
diff --git a/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/util/ApplicationClassLoader.java b/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/util/ApplicationClassLoader.java
index 2f46e1f..9b89889 100644
--- a/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/util/ApplicationClassLoader.java
+++ b/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/util/ApplicationClassLoader.java
@@ -158,49 +158,49 @@
}
@Override
- protected synchronized Class<?> loadClass(String name, boolean resolve)
+ protected Class<?> loadClass(String name, boolean resolve)
throws ClassNotFoundException {
-
- if (LOG.isDebugEnabled()) {
- LOG.debug("Loading class: " + name);
- }
+ synchronized (getClassLoadingLock(name)) {
+ if (LOG.isDebugEnabled()) {
+ LOG.debug("Loading class: " + name);
+ }
- Class<?> c = findLoadedClass(name);
- ClassNotFoundException ex = null;
+ Class<?> c = findLoadedClass(name);
+ ClassNotFoundException ex = null;
- if (c == null && !isSystemClass(name, systemClasses)) {
- // Try to load class from this classloader's URLs. Note that this is like
- // the servlet spec, not the usual Java 2 behaviour where we ask the
- // parent to attempt to load first.
- try {
- c = findClass(name);
+ if (c == null && !isSystemClass(name, systemClasses)) {
+ // Try to load class from this classloader's URLs. Note that this is
+ // like the servlet spec, not the usual Java 2 behaviour where we ask
+ // the parent to attempt to load first.
+ try {
+ c = findClass(name);
+ if (LOG.isDebugEnabled() && c != null) {
+ LOG.debug("Loaded class: " + name + " ");
+ }
+ } catch (ClassNotFoundException e) {
+ if (LOG.isDebugEnabled()) {
+ LOG.debug(e);
+ }
+ ex = e;
+ }
+ }
+
+ if (c == null) { // try parent
+ c = parent.loadClass(name);
if (LOG.isDebugEnabled() && c != null) {
- LOG.debug("Loaded class: " + name + " ");
+ LOG.debug("Loaded class from parent: " + name + " ");
}
- } catch (ClassNotFoundException e) {
- if (LOG.isDebugEnabled()) {
- LOG.debug(e);
- }
- ex = e;
}
- }
- if (c == null) { // try parent
- c = parent.loadClass(name);
- if (LOG.isDebugEnabled() && c != null) {
- LOG.debug("Loaded class from parent: " + name + " ");
+ if (c == null) {
+ throw ex != null ? ex : new ClassNotFoundException(name);
}
- }
- if (c == null) {
- throw ex != null ? ex : new ClassNotFoundException(name);
+ if (resolve) {
+ resolveClass(c);
+ }
+ return c;
}
-
- if (resolve) {
- resolveClass(c);
- }
-
- return c;
}
/**
