I have extracted a jar from a Maven project that runs the MapReduce job. However, I keep receiving the error "java.lang.ClassNotFoundException". The things that I have tried to use to repair this is:
Configured the classpath
Tried doing job.setJar(.jar)
Attempted job.setJarbyClass(.class)
Changing JobConf path file
Caress Hadoop and tell it everything is going to be okay
I extracted the jar file from Maven and transferred it to a Linux server, and running it from there.
The full error message is:
Exception in thread "main" java.lang.ClassNotFoundException: BLAMapAttempt2
at java.net.URLClassLoader.findClass(URLClassLoader.java:381)
at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
at java.lang.Class.forName0(Native Method)
at java.lang.Class.forName(Class.java:348)
at org.apache.hadoop.util.RunJar.run(RunJar.java:214)
at org.apache.hadoop.util.RunJar.main(RunJar.java:136)
If there is any missing information needed to answer this question, please let me know, and thank you for reading.
When exporting the jar out of Eclipse, I unchecked "classpath" because I was not running it locally. This fixed my error.
Related
I am trying to run a program on the command line that uses the JavaMail API. This program also reads in a message from a text file. However, I'm getting this error:
Error: A JNI error has occurred, please check your installation and try again
Exception in thread "main" java.lang.NoClassDefFoundError: javax/mail/Address
at java.lang.Class.getDeclaredMethods0(Native Method)
at java.lang.Class.privateGetDeclaredMethods(Class.java:2701)
at java.lang.Class.privateGetMethodRecursive(Class.java:3048)
at java.lang.Class.getMethod0(Class.java:3018)
at java.lang.Class.getMethod(Class.java:1784)
at sun.launcher.LauncherHelper.validateMainClass(LauncherHelper.java:544)
at sun.launcher.LauncherHelper.checkAndLoadMain(LauncherHelper.java:526)
Caused by: java.lang.ClassNotFoundException: javax.mail.Address
at java.net.URLClassLoader.findClass(URLClassLoader.java:381)
at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:331)
at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
... 7 more
Originally I used java -cp /path/to/mail.jar mailTest < message.txt
I configured the classpath for the jar successfully (as far as I know). Can anyone give me some pointers? :/
Your classpath is definitely wrong. The classpath needs to include both the javax.mail.jar file and the classes for your application. Exactly where is the JavaMail jar file, exactly where are your application classes, and exactly what java command line did you use? If your application classes are in the current directory, you need something like
java -cp /path/to/javax.mail.jar:. mailTest
Actually if you look at the error message:
Caused by: java.lang.ClassNotFoundException: javax.mail.Address
That's probably because your jar depends on another jar (probably mail-x.y.z.jar) and you did not include it on your classpath when trying to run your jar.
Either include the missing jar(s) on the command line, see this post, or add them to your manifest file, see the doc
When I execute mycode from intelliJ Idea it works fine but when I run the jar on my server it throws the below error. I am using 'org.mongodb:mongodb-driver:3.4.1' version.
Exception in thread "main" java.lang.NoClassDefFoundError: org/bson/conversions/Bson
at com.myapp.server.mongo.MongoDbHandler.prepareMongoDb(MongoDbHandler.java:68)
at com.myapp.server.mongo.MongoDbHandler.<init>(MongoDbHandler.java:22)
at com.myapp.server.Client.main(Client.java:167)
Caused by: java.lang.ClassNotFoundException: org.bson.conversions.Bson
at java.net.URLClassLoader$1.run(URLClassLoader.java:372)
at java.net.URLClassLoader$1.run(URLClassLoader.java:361)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(URLClassLoader.java:360)
at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:308)
at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
... 3 more
I know its an old thread and its just for those who have the similar issues. Few days back I was also facing the same issue with same error trace while running the jar by command line.After rechecking the code found that
It was not a problem of the jar version but its problem of the packaging of the
jar
After packing the jar with all proper dependencies will solve this issue.
I have used
maven-assembly-plugin
for packaging and its works.
.
If I had to guess you need to get yourself whatever BSON library you're using; I wouldn't say that Mongo is your problem.
key line here is:
"Caused by: java.lang.ClassNotFoundException: org.bson.conversions.Bson"
So it's saying that it's not finding that particular class, I would look in IntelliJ and see what BSON library it is, then put it in your build directory (or java lib) on your server.
We are trying to execute basic Hbase example on hortonworks sandbox (2.3).
hadoop jar /usr/hdp/2.3.0.0-2557/hbase/lib/hbase-examples.jar org.apache.hadoop.hbase.mapreduce.IndexBuilder
We are getting below exception after executing this program.
Exception in thread "main" java.lang.NoClassDefFoundError: org/apache/hadoop/hbase/util/Bytes
at org.apache.hadoop.hbase.mapreduce.IndexBuilder.<clinit>(IndexBuilder.java:67)
at java.lang.Class.forName0(Native Method)
at java.lang.Class.forName(Class.java:278)
at org.apache.hadoop.util.RunJar.run(RunJar.java:214)
at org.apache.hadoop.util.RunJar.main(RunJar.java:136)
Caused by: java.lang.ClassNotFoundException: org.apache.hadoop.hbase.util.Bytes
at java.net.URLClassLoader$1.run(URLClassLoader.java:366)
at java.net.URLClassLoader$1.run(URLClassLoader.java:355)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(URLClassLoader.java:354)
at java.lang.ClassLoader.loadClass(ClassLoader.java:425)
at java.lang.ClassLoader.loadClass(ClassLoader.java:358)
... 5 more
Based on this error we tried to set the Hadoop classpath in Hbase-env.sh.
/usr/hdp/2.3.0.0-2557/hbase/lib/hbase-client-1.1.1.2.3.0.0-2557.jar:/usr/hdp/2.3.0.0-2557/hbase/lib/hbase-common-1.1.1.2.3.0.0-2557.jar:/usr/hdp/2.3.0.0-2557/hbase/lib/protobuf-java-2.5.0.jar:/usr/hdp/2.3.0.0-2557/hbase/lib/guava-12.0.1.jar:$/usr/hdp/2.3.0.0-2557/hbase/lib/zookeeper.jar:/usr/hdp/2.3.0.0-2557/hbase/lib/hbase-protocol-1.1.1.2.3.0.0-2557.jar:/usr/hdp/2.3.0.0-2557/hbase/lib/commons-configuration-1.6.jar:/usr/hdp/2.3.0.0-2557/hbase/lib/hadoop-common.jar:/usr/hdp/2.3.0.0-2557/hbase/lib/hbase-0.94.27.jar
But still getting the same error.
Instead of manually adding jars into classpath you can directly use below command.
$(hbase classpath) recursively search in hortonworks hadoop folders and finds the required jars from sandbox.
HADOOP_CLASSPATH=$(hbase classpath):/usr/hdp/2.3.0.0-2557/hbase/conf hadoop jar /usr/hdp/2.3.0.0-2557/hbase/lib/hbase-examples.jar org.apache.hadoop.hbase.mapreduce.IndexBuilder
When I face NoClassDefFoundError error with mapreduce, I add jar using one of the jar class in JobBuilder to resolve it.
e.g.
Job job = new Job(conf);
job.setJarByClass(org.apache.hadoop.hbase.util.Bytes.class);
Supply jars using libjars parameter to your job-
e.g.
LIB=hbase-x.x.x.jar
hadoop jar /usr/hdp/2.3.0.0-2557/hbase/lib/hbase-examples.jar org.apache.hadoop.hbase.mapreduce.IndexBuilder -libjars ${LIB}
you can also add jar to HADOOP_CLASSPATH variable before launch job.
Is all the latest code included in the jar? Use a java decompiler such as jd-gui to look inside the jar file to make sure this class you are referencing is actually there. Also check that the necessary import statements are present in the Java class.
I downloaded the confluent package which includes camus jars and I followed the instructions online enter link description here.
Hadoop is properly setup (meaning I can use hadoop fs -ls commands and other hadoop jar commands). However, when i tried to run
hadoop jar confluent-camus-1.0.jar com.linkedin.camus.etl.kafka.CamusJob
I got "main" classNotFound error
Exception in thread "main" java.lang.ClassNotFoundException: com.linkedin.camus.
etl.kafka.CamusJob
at java.net.URLClassLoader$1.run(URLClassLoader.java:372)
at java.net.URLClassLoader$1.run(URLClassLoader.java:361)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(URLClassLoader.java:360)
at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
at java.lang.Class.forName0(Native Method)
at java.lang.Class.forName(Class.java:344)
at org.apache.hadoop.util.RunJar.main(RunJar.java:205)
The the path to the "confluent-camus-1.0.jar" is correct (right under the folder). I didn't start the kafka service, just to try to run it.
Anyone got similar problems?
Thanks.
You should try to inspect your jar file:
jar tvf confluent-camus-1.0.jar | grep com.linkedin.camus.etl.kafka.CamusJob
If you do not find this class, try to find it in other jar, which generated by camus.
After you should add target jar with
hadoop jar confluent-camus-1.0.jar com.linkedin.camus.etl.kafka.CamusJob -libjars {JAR_NAME}
I'm trying to make a Java program that can communicate with JavaDB. I've made the Database class, started a server and made a tiny client program to check if they would communicate.
The program crashes when i try to run it, giving a class not found exception at the line where i try to set the database driver. I googled it and found that this error appears if derbyclient.jar and derby.jar are not found in the classpath. I also read that the scripts setNetworkClientCP and setNetworkServerCP found in the db directory would set these in the classpath. I found the scripts, ran them, and checked to make sure the classpath got updated, but i still get the same error. Does anyone know what the problem might be?
EDIT: SOLVED - i just realized that i need to include the derbyclient.jar in the NetBeans project library.
I'm using NetBeans and the built in JavaDB. I set the classpath by using the scripts that i mentioned above, and upon checking the classpath i found these entries:
%DERBY_INSTALL%\lib\derbyclient.jar;
%DERBY_INSTALL%\lib\derby.jar;
%DERBY_INSTALL%\lib\derbytools.jar;
%DERBY_INSTALL%\lib\derbynet.jar;
The Error:
java.lang.ClassNotFoundException: org.apache.derby.jdbc.ClientDriver
at java.net.URLClassLoader$1.run(URLClassLoader.java:372)
at java.net.URLClassLoader$1.run(URLClassLoader.java:361)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(URLClassLoader.java:360)
at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:308)
at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
at java.lang.Class.forName0(Native Method)
at java.lang.Class.forName(Class.java:260)
at Database.<init>(Database.java:14)
at TestKlient.main(TestKlient.java:8)