Abgeschickt von Eric am 01 Maerz, 2006 um 23:10:33
<p>This is a great project... saved me from implementing the wheel again for liveitup.com, which requires us to log our message to a database. Makes it easier to read and generate troubleshooting reports... especially in a high-traffic and clustered server environment. I'm getting off topic now.</p>
<p>I setup our log4j environment to use JDBCAppenders; create the tables and configured appender. Some of the columns I have are of type DYNAMIC and it's giving me some problems. Here's the error message I'm getting:</p>
<p><pre>[3/1/06 16:54:04:734 EST] 42bd42bd SystemErr R log4j:ERROR JDBCAppender::configure()
[3/1/06 16:54:04:734 EST] 42bd42bd SystemErr R java.lang.Exception: JDBCLogger::setLogType(), Cannot cast value of class class java.lang.String to class JDBCColumnHandler !
[3/1/06 16:54:04:859 EST] 42bd42bd SystemErr R at java.lang.Throwable.<init>(Throwable.java)
[3/1/06 16:54:04:859 EST] 42bd42bd SystemErr R at java.lang.Throwable.<init>(Throwable.java)
[3/1/06 16:54:04:859 EST] 42bd42bd SystemErr R at org.apache.log4j.jdbcplus.JDBCLogger.setLogType(JDBCLogger.java)
[3/1/06 16:54:04:859 EST] 42bd42bd SystemErr R at org.apache.log4j.jdbcplus.JDBCAppender.configure(JDBCAppender.java:1027)
[3/1/06 16:54:04:859 EST] 42bd42bd SystemErr R at org.apache.log4j.jdbcplus.JDBCAppender.ready(JDBCAppender.java:921)
[3/1/06 16:54:04:859 EST] 42bd42bd SystemErr R at org.apache.log4j.jdbcplus.JDBCAppender.append(JDBCAppender.java)
[3/1/06 16:54:04:859 EST] 42bd42bd SystemErr R at org.apache.log4j.AppenderSkeleton.doAppend(AppenderSkeleton.java)
[3/1/06 16:54:04:859 EST] 42bd42bd SystemErr R at org.apache.log4j.helpers.AppenderAttachableImpl.appendLoopOnAppenders(AppenderAttachableImpl.java)
[3/1/06 16:54:04:859 EST] 42bd42bd SystemErr R at org.apache.log4j.Category.callAppenders(Category.java)
[3/1/06 16:54:04:859 EST] 42bd42bd SystemErr R at org.apache.log4j.Category.forcedLog(Category.java)
[3/1/06 16:54:04:859 EST] 42bd42bd SystemErr R at org.apache.log4j.Category.log(Category.java)
[3/1/06 16:54:04:875 EST] 42bd42bd SystemErr R at org.apache.commons.logging.impl.Log4JLogger.info(Log4JLogger.java:133)
[3/1/06 16:54:04:875 EST] 42bd42bd SystemErr R at org.springframework.web.servlet.mvc.multiaction.MultiActionController.setDelegate(MultiActionController.java:213)</pre></p>
<p><br/>I started debugging through and the error is occuring in JDBCLogger on line 251 with version 2.1.01, which is the following:</p>
<p>logcol.columnHandler = (JDBCColumnHandler) (Class
.forName((String) _value).newInstance());
</p>
<p>Has anyone encountered this before? Why can't it seem to properly load my column handler class? Also, what is strange is that the exception message is reporting that it's trying to cass a String to a JDBCColumnHandler, which is fine considering the code listed in previous paragraph is suppose to load a new instance of the column handler class using the FQN string of the class. No?</p>
<p>I'm wondering if this might not be a class loader issue?</p>