Static blocks do not automatically run when a class is loaded in Java 5.0
-------------------------------------------------------------------------
Key: HADOOP-367
URL: http://issues.apache.org/jira/browse/HADOOP-367
Project: Hadoop
Issue Type: Bug
Components: dfs
Affects Versions: 0.4.0
Environment: Java 5.0
Reporter: Benjamin Reed
There seems to be a change that happened between 1.4 and 1.5 with respect to
static initializers. I can't find this documented, but I can reproduce with a
very simple program. Basically, a static initializer is not called unless a
static member/method of the class is accessed or an instance is created. This
is actually what the JLS says, but until 1.5 the static initializers ran when
the class was loaded. Note that this behavior only occurs when running with the
1.5 JRE AND compiling for 1.5.
For many Writables this isn't an issue, so the fallback behavior of the
WritableFactory works, but Block is package private, so loadEdits fails when
called from org.apache.hadoop.io.ArrayWritable.readFields() yielding the
following trace:
Caused by: java.lang.RuntimeException: java.lang.IllegalAccessException: Class
org.apache.hadoop.io.WritableFactories can not access a member of class
org.apache.hadoop.dfs.Block with modifiers "public"
at
org.apache.hadoop.io.WritableFactories.newInstance(WritableFactories.java:49)
at org.apache.hadoop.io.ArrayWritable.readFields(ArrayWritable.java:81)
at org.apache.hadoop.dfs.FSDirectory.loadFSEdits(FSDirectory.java:532)
at org.apache.hadoop.dfs.FSDirectory.loadFSImage(FSDirectory.java:470)
at org.apache.hadoop.dfs.FSDirectory.<init>(FSDirectory.java:307)
at org.apache.hadoop.dfs.FSNamesystem.<init>(FSNamesystem.java:177)
at org.apache.hadoop.dfs.NameNode.<init>(NameNode.java:91)
at org.apache.hadoop.dfs.NameNode.<init>(NameNode.java:84)
at org.apache.hadoop.dfs.NameNode.main(NameNode.java:491)
--
This message is automatically generated by JIRA.
-
If you think it was sent incorrectly contact one of the administrators:
http://issues.apache.org/jira/secure/Administrators.jspa
-
For more information on JIRA, see: http://www.atlassian.com/software/jira
