Kamis, 05 Juni 2014

java.lang.ClassNotFoundException: oracle.jdbc.driver.OracleDriver - cause and solution




java.lang.ClassNotFoundException:
oracle.jdbc.driver.OracleDriver Exception
comes when you try to connect
Oracle database from Java program and Oracle driver is not available in Classpath. We have already
seen How to connect Oracle database from Java
program
and found that, In order to connect to Oracle database, we
load and register driver using
Class.forName("oracle.jdbc.driver.OracleDriver") and this
code loads class at runtime using
Reflection which throws
ClassNotFoundException if class in question e.g.
"
oracle.jdbc.driver.OracleDriver" is not found. I have
already listed down various reason of ClassNotFoundExcepiton in Java,
which is also applicable in this case. By the way
java.lang.ClassNotFoundException:
oracle.jdbc.driver.OracleDriver
is similar to 
java.lang.ClassNotFoundException:
mysql.jdbc.driver.MySQLDriver
w
hich comes if you try to connect
MySQL database from Java program and corresponding driver is not in your
classpath. You can refer link for getting more ideas which can be used to fix
java.lang.ClassNotFoundException:
oracle.jdbc.driver.OracleDriver
error as well.




How to solve
java.lang.ClassNotFoundException: oracle.jdbc.driver.OracleDriver



How to fix java.lang.ClassNotFoundException: oracle.jdbc.driver.OracleDriver in Java


In order to solve java.lang.ClassNotFoundException:
oracle.jdbc.driver.OracleDriver
, we need these class either in form of JAR or classes in your
application classpath. For Oracle 10g and 11g these are present in
ojdbc6.jar or ojdbc6_g.jar, which are
same except later is compiled with
javac -g option to
include debug information and tracing code. If you don't have this JAR then you
can download it from http://www.oracle.com/technetwork/database/enterprise-edition/jdbc-112010-090769.html.
Just download this JAR file and add into your Classpath by following steps
given in How to set Classpath in Java.
If
you are not very comfortable with setting classpath then you can also put
this JAR file in JRE/ext directory
C:\Program
Files\Java\jdk1.6.0_20\jre\lib\ext
which is used by extension class loader to load class file, though its not advisable and you should only do
this for testing, as chances of leaving that
ojdbc6.jar is more
which may cause in future if you have a new version of driver some where else
in Application classpath but your Java application still picking this old
drivers. See How classloader works in Java
for more details on this issue.





That's all on How to fix java.lang.ClassNotFoundException:
oracle.jdbc.driver.OracleDriver
in Java. This is like any other standard java.lang.ClassNotFoundException except
that you should know on which JAR file you can find this driver i.e.
ojdbc6.jar. If you
are using Eclipse then you can just include this JAR in your build path by
selecting project, right click, properties, Java Build path and then adding JAR
on libraries tab. You can even verify whether
oracle.jdbc.driver.OracleDriver is in your
Classpath or not by using Eclipse shortcut for checking classes in
project classpath
.





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Source:http://javarevisited.blogspot.com/2012/12/classnotfoundexception-oracle-jdbc-driver-oracledriver.html

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