Grails 2.5.0 + mongo + hibernate - mysql

I am trying to use hibernate with mongo driver and experiencing some issues:
I have created brand new grails app, using grails 2.5.0. changed dataSource.groovy to point to mysql, uncommented mysql-connector-java:5.1.29 and everything works fine.
But when i am adding compile "org.grails.plugins:mongodb:5.0.0.RC1" to plugins section in Build Config i get this on startup:
| Error 2016-02-22 14:32:29,439 [localhost-startStop-1] ERROR context.GrailsContextLoaderListener - Error initializing the application: org.codehaus.groovy.grails.orm.hibernate.cfg.GrailsDomainBinder.evaluateMapping
what am i missing?
NB! App does not start, so all internal mappings don't matter at this point.
Here is my config files:
Datasource -> https://cldup.com/GnXUJDOy0b.txt
BuildConfig ->https://cldup.com/xtk5l1F_BW.txt
Error -> https://cldup.com/NJ7vpoX3Kb.txt

It could be useful if you show more code but seems you are not setting the mapping for mongo in the domain class definition :
static mapWith="mongo"
Here you can find an useful tutorial about this

I could not find a way to make mongodb 5.0.1 to work, after days of searching found this answer. This solution worked.
plugins {
compile (":mongodb:3.0.2") {
excludes 'grails-datastore-gorm-plugin-support'
excludes 'grails-datastore-gorm'
excludes 'grails-datastore-core'
}
}
and then in dependencies, pull the correct ones in:
dependencies {
compile 'org.grails:grails-datastore-gorm-plugin-support:3.1.3.RELEASE'
compile 'org.grails:grails-datastore-gorm:3.1.3.RELEASE'
compile 'org.grails:grails-datastore-core:3.1.3.RELEASE'
}
from here Cannot install Grails MongoDB plugin
Hope this will save someone a great deal of time and effort.

Related

Dropped rows in Spark when modifying database in MySQL

I've been following the 5 min how to for setting up an htap databse with tidb_tispark and everything works until I get to the section Launch TiSpark. My first issue occurs when executing the line:
docker-compose exec tispark-master /opt/spark-2.1.1-bin-hadoop2.7/bin/spark-shell
But I got around that by modifying the spark version to the version I found inside the container:
docker-compose exec tispark-master /opt/spark-2.3.3-bin-hadoop2.7/bin/spark-shell
My second issue occurs when executing the three line block:
import org.apache.spark.sql.TiContext
val ti = new TiContext(spark)
ti.tidbMapDatabase("TPCH_001")
When I run the last statement I get the following output
scala> ti.tidbMapDatabase("TPCH_001")
2019-07-11 16:14:32 WARN General:96 - Plugin (Bundle) "org.datanucleus" is already registered. Ensure you dont have multiple JAR versions of the same plugin in the classpath. The URL "file:/opt/spark/jars/datanucleus-core-3.2.10.jar" is already registered, and you are trying to register an identical plugin located at URL "file:/opt/spark-2.3.3-bin-hadoop2.7/jars/datanucleus-core-3.2.10.jar."
2019-07-11 16:14:32 WARN General:96 - Plugin (Bundle) "org.datanucleus.api.jdo" is already registered. Ensure you dont have multiple JAR versions of the same plugin in the classpath. The URL "file:/opt/spark/jars/datanucleus-api-jdo-3.2.6.jar" is already registered, and you are trying to register an identical plugin located at URL "file:/opt/spark-2.3.3-bin-hadoop2.7/jars/datanucleus-api-jdo-3.2.6.jar."
2019-07-11 16:14:32 WARN General:96 - Plugin (Bundle) "org.datanucleus.store.rdbms" is already registered. Ensure you dont have multiple JAR versions of the same plugin in the classpath. The URL "file:/opt/spark/jars/datanucleus-rdbms-3.2.9.jar" is already registered, and you are trying to register an identical plugin located at URL "file:/opt/spark-2.3.3-bin-hadoop2.7/jars/datanucleus-rdbms-3.2.9.jar."
2019-07-11 16:14:36 WARN ObjectStore:568 - Failed to get database global_temp, returning NoSuchObjectException
This doesn't prevent me from running the query:
spark.sql("select * from nation").show(30);
But when I follow the further steps of the tutorial to modify the db from MySQL, the changes are not reflected immediately in Spark. Furthermore, at some point in the future (I believe > 5 minutes later), the row that was modified stops showing up in Spark SQL queries.
I'm rather new to this kind of setup and don't really know how to debug this issue. Searches for the warnings I received weren't illuminating.
I don't know if it's helpful but when I connect MySQL this is the server version I get:
Server version: 5.7.25-TiDB-v3.0.0-rc.1-309-g8c20289c7 MySQL Community Server (Apache License 2.0)
I'm one of the main dev of TiSpark. Sorry for your bad experience with it.
Due to my docker problem, I cannot directly reproduce your issue but it seems you hit one of the bug fixed recently.
https://github.com/pingcap/tispark/pull/862/files
The tutorial document is not quite up-to-date and points to an older version. That's why it didn't work with spark 2.1.1 as in tutorial. We will update it ASAP.
Newer version of TiSpark doesn't use tidbMapDatabase anymore but hooks with catalog directly instead. Method tidbMapDatabase remains for backward compatibility. Unfortunately, the tidbMapDatabase had a bug(when we ported it from older version) that it retrieves timestamp for query only once you call the function. That causes TiSpark always uses old timestamp to do snapshot reading and newer data would never be seen by it.
In newer version of TiSpark (TiSpark 2.0+ with Spark 2.3+), databases and tables are directly hooked into catalog services and you can directly call
spark.sql("use TPCH_001").show
spark.sql("select * from nation").show
This should give you fresh data.
So try restart your Spark driver, just try the two lines of code above and see if it works.
Let me know if this fix your problem. On the other hand, we will check our docker image to make sure if it contains the fix already.
If things still get wrong, would you please help to run below code and let us know the version of TiSpark.
spark.sql("select ti_version()").show
Again, sorry for causing you trouble and thanks for trying.
EDIT
To address your comment:
The warning is due to spark itself will try to locate the database in its native catalog first and this will cause a Failed to get warning. But the failover process will delegate the search to tispark and then behave correctly. So this warning can be ignored. It's recommended that add below lines to your log4j.properties in conf folder of your spark.
log4j.logger.org.apache.hadoop.hive.metastore.ObjectStore=ERROR
We will polish the docker tutorial image soon. Thank you so much for trying.

Service fabric upgrade failing due to change in namespace

I have a service fabric application stuck in "Upgrading" mode.
The exception is:
Could not load type 'DB.IAddUser' from assembly 'DB' at
WebApi.Startup.ConfigureServices(IServiceCollection services)
My change was that of renaming the name space, from 'DB' to 'DB.Interfaces'.
This class is only used as a constructor dependency, and registered as such
Startup.cs
services.AddSingleton<IAddUser, AddUser>();
UserController.cs
private IAddUser addUser;
public UserController(IAddUser addUser){
this.addUser = addUser;
}
Why would this cause SF to get stuck?
Additionally, it only got stuck on the last upgrade domain, and not on the others.
I might be mistaken but if upgrade was successful on other upgrade domains then it is not code related issue.
Try to rollback the application upgrade and upgrade again:
Start-ServiceFabricApplicationRollback -ApplicationName fabric:/MyApp
documentation
It turns out that this had nothing to do with service fabric (as expected and as #SteppingRazor said).
The problem seems to be related to MSBuild/Azure devops build task, I had upgraded nuget package
Microsoft.VisualStudio.Azure.Fabric.MSBuild
from 1.6.7 to 1.6.8 and it seems that the build was still using older code (confirmed via a decompiler).
Reverting back to 1.6.7 solved the issue (albeit its just a workaround)

connecting MySQL using wamp and hibernate in eclipse [duplicate]

I'm trying to add a database-enabled JSP to an existing Tomcat 5.5 application (GeoServer 2.0.0, if that helps).
The app itself talks to Postgres just fine, so I know that the database is up, user can access it, all that good stuff. What I'm trying to do is a database query in a JSP that I've added. I've used the config example in the Tomcat datasource example pretty much out of the box. The requisite taglibs are in the right place -- no errors occur if I just have the taglib refs, so it's finding those JARs. The postgres jdbc driver, postgresql-8.4.701.jdbc3.jar is in $CATALINA_HOME/common/lib.
Here's the top of the JSP:
<%# taglib uri="http://java.sun.com/jsp/jstl/sql" prefix="sql" %>
<%# taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c" %>
<sql:query var="rs" dataSource="jdbc/mmas">
select current_validstart as ValidTime from runoff_forecast_valid_time
</sql:query>
The relevant section from $CATALINA_HOME/conf/server.xml, inside the <Host> which is in turn within <Engine>:
<Context path="/gs2" allowLinking="true">
<Resource name="jdbc/mmas" type="javax.sql.Datasource"
auth="Container" driverClassName="org.postgresql.Driver"
maxActive="100" maxIdle="30" maxWait="10000"
username="mmas" password="very_secure_yess_precious!"
url="jdbc:postgresql//localhost:5432/mmas" />
</Context>
These lines are the last in the tag in webapps/gs2/WEB-INF/web.xml:
<resource-ref>
<description>
The database resource for the MMAS PostGIS database
</description>
<res-ref-name>
jdbc/mmas
</res-ref-name>
<res-type>
javax.sql.DataSource
</res-type>
<res-auth>
Container
</res-auth>
</resource-ref>
Finally, the exception:
exception
org.apache.jasper.JasperException: Unable to get connection, DataSource invalid: "java.sql.SQLException: No suitable driver"
[...wads of ensuing goo elided]
The infamous java.sql.SQLException: No suitable driver found
This exception can have basically two causes:
1. JDBC driver is not loaded
In case of Tomcat, you need to ensure that the JDBC driver is placed in server's own /lib folder.
Or, when you're actually not using a server-managed connection pool data source, but are manually fiddling around with DriverManager#getConnection() in WAR, then you need to place the JDBC driver in WAR's /WEB-INF/lib and perform ..
Class.forName("com.example.jdbc.Driver");
.. in your code before the first DriverManager#getConnection() call whereby you make sure that you do not swallow/ignore any ClassNotFoundException which can be thrown by it and continue the code flow as if nothing exceptional happened. See also Where do I have to place the JDBC driver for Tomcat's connection pool?
Other servers have a similar way of placing the JAR file:
GlassFish: put the JAR file in /glassfish/lib
WildFly: put the JAR file in /standalone/deployments
2. Or, JDBC URL is in wrong syntax
You need to ensure that the JDBC URL is conform the JDBC driver documentation and keep in mind that it's usually case sensitive. When the JDBC URL does not return true for Driver#acceptsURL() for any of the loaded drivers, then you will also get exactly this exception.
In case of PostgreSQL it is documented here.
With JDBC, a database is represented by a URL (Uniform Resource Locator). With PostgreSQL™, this takes one of the following forms:
jdbc:postgresql:database
jdbc:postgresql://host/database
jdbc:postgresql://host:port/database
In case of MySQL it is documented here.
The general format for a JDBC URL for connecting to a MySQL server is as follows, with items in square brackets ([ ]) being optional:
jdbc:mysql://[host1][:port1][,[host2][:port2]]...[/[database]] » [?propertyName1=propertyValue1[&propertyName2=propertyValue2]...]
In case of Oracle it is documented here.
There are 2 URL syntax, old syntax which will only work with SID and the new one with Oracle service name.
Old syntax jdbc:oracle:thin:#[HOST][:PORT]:SID
New syntax jdbc:oracle:thin:#//[HOST][:PORT]/SERVICE
See also:
Where do I have to place the JDBC driver for Tomcat's connection pool?
How to install JDBC driver in Eclipse web project without facing java.lang.ClassNotFoundexception
How should I connect to JDBC database / datasource in a servlet based application?
What is the difference between "Class.forName()" and "Class.forName().newInstance()"?
Connect Java to a MySQL database
I've forgot to add the PostgreSQL JDBC Driver into my project (Mvnrepository).
Gradle:
// http://mvnrepository.com/artifact/postgresql/postgresql
compile group: 'postgresql', name: 'postgresql', version: '9.0-801.jdbc4'
Maven:
<dependency>
<groupId>postgresql</groupId>
<artifactId>postgresql</artifactId>
<version>9.0-801.jdbc4</version>
</dependency>
You can also download the JAR and import to your project manually.
url="jdbc:postgresql//localhost:5432/mmas"
That URL looks wrong, do you need the following?
url="jdbc:postgresql://localhost:5432/mmas"
I faced the similar issue.
My Project in context is Dynamic Web Project(Java 8 + Tomcat 8) and error is for PostgreSQL Driver exception: No suitable driver found
It got resolved by adding Class.forName("org.postgresql.Driver") before calling getConnection() method
Here is my Sample Code:
try {
Connection conn = null;
Class.forName("org.postgresql.Driver");
conn = DriverManager.getConnection("jdbc:postgresql://" + host + ":" + port + "/?preferQueryMode="
+ sql_auth,sql_user , sql_password);
} catch (Exception e) {
System.out.println("Failed to create JDBC db connection " + e.toString() + e.getMessage());
}
I found the followig tip helpful, to eliminate this issue in Tomcat -
be sure to load the driver first doing a Class.forName("
org.postgresql.Driver"); in your code.
This is from the post - https://www.postgresql.org/message-id/e13c14ec050510103846db6b0e#mail.gmail.com
The jdbc code worked fine as a standalone program but, in TOMCAT it gave the error -'No suitable driver found'
No matter how old this thread becomes, people would continue to face this issue.
My Case: I have the latest (at the time of posting) OpenJDK and maven setup. I had tried all methods given above, with/out maven and even solutions on sister posts on StackOverflow. I am not using any IDE or anything else, running from bare CLI to demonstrate only the core logic.
Here's what finally worked.
Download the driver from the official site. (for me it was MySQL https://www.mysql.com/products/connector/). Use your flavour here.
Unzip the given jar file in the same directory as your java project. You would get a directory structure like this. If you look carefully, this exactly relates to what we try to do using Class.forName(....). The file that we want is the com/mysql/jdbc/Driver.class
Compile the java program containing the code.
javac App.java
Now load the director as a module by running
java --module-path com/mysql/jdbc -cp ./ App
This would load the (extracted) package manually, and your java program would find the required Driver class.
Note that this was done for the mysql driver, other drivers might require minor changes.
If your vendor provides a .deb image, you can get the jar from /usr/share/java/your-vendor-file-here.jar
Summary:
Soln2 (recommend)::
1 . put mysql-connector-java-8.0.28.jar file in the <where you install your Tomcat>/lib.
Soln1::
1 . put mysql-connector-java-8.0.28.jar file in the WEB-INF/lib.
2 . use Class.forName("com.mysql.cj.jdbc.Driver"); in your Servlet Java code.
Soln1 (Ori Ans) //-20220304
In short:
make sure you have the mysql-connector-java-8.0.28.jar file in the WEB-INF/lib
make sure you use the Class.forName("com.mysql.cj.jdbc.Driver");
additional notes (not important), base on my trying (could be wrong)::
1.1 putting the jar directly inside the Java build path doesnt work
1.2. putting the jar in Data management > Driver Def > MySQL JDBC Driver > then add it as library to Java Build path doesnt work.
1.3 => it has to be inside the WEB-INF/lib (I dont know why)
1.4 using version mysql-connector-java-8.0.28.jar works, only version 5.1 available in Eclipse MySQL JDBC Driver setting doesnt matter, ignore it.
<see How to connect to MySql 8.0 database using Eclipse Database Management Perspective >
Class.forName("com.mysql.cj.jdbc.Driver");
Class.forName("com.mysql.jdbc.Driver");
both works,
but the Class.forName("com.mysql.jdbc.Driver"); is deprecated.
Loading class `com.mysql.jdbc.Driver'. This is deprecated. The new driver class is `com.mysql.cj.jdbc.Driver'. The driver is automatically registered via the SPI and manual loading of the driver class is generally unnecessary.
<see https://www.yawintutor.com/no-suitable-driver-found-for-jdbcmysql-localhost3306-testdb/ >
If you want to connect to a MySQL database, you can use the type-4 driver named Connector/} that's available for free from the MySQL website. However, this driver is typically included in Tomcat's lib directory. As a result, you don't usually need to download this driver from the MySQL site.
-- Murach’s Java Servlets and JSP
I cant find the driver in Tomcat that the author is talking about, I need to use the mysql-connector-java-8.0.28.jar.
<(striked-out) see updated answer soln2 below>
If you're working with an older version of Java, though, you need to use the forName method of the Class class to explicitly load the driver before you call the getConnection method
Even with JDBC 4.0, you sometimes get a message that says, "No suitable driver found." In that case, you can use the forName method of the Class class to explicitly load the driver. However, if automatic driver loading works, it usually makes sense to remove this method call from your code.
How to load a MySQL database driver prior to JDBC 4.0
Class.forName{"com.mysql.jdbc.Driver");
-- Murach’s Java Servlets and JSP
I have to use Class.forName("com.mysql.cj.jdbc.Driver"); in my system, no automatic class loading. Not sure why.
<(striked-out) see updated answer soln2 below>
When I am using a normal Java Project instead of a Dynamic Web Project in Eclipse,
I only need to add the mysql-connector-java-8.0.28.jar to Java Build Path directly,
then I can connect to the JDBC with no problem.
However, if I am using Dynamic Web Project (which is in this case), those 2 strict rules applies (jar position & class loading).
<see TOMCAT ON ECLIPSE java.sql.SQLException: No suitable driver found for jdbc:mysql >
Soln2 (Updated Ans) //-20220305_12
In short:
1 . put mysql-connector-java-8.0.28.jar file in the <where you install your Tomcat>/lib.
eg: G:\pla\Java\apache-tomcat-10.0.16\lib\mysql-connector-java-8.0.28.jar
(and for an Eclipse Dynamic Web Project, the jar will then be automatically put inside in your project's Java build path > Server Runtime [Apache Tomcat v10.0].)
Additional notes::
for soln1::
put mysql-connector-java-8.0.28.jar file in the WEB-INF/lib.
use Class.forName("com.mysql.cj.jdbc.Driver"); in your Servlet Java code.
this will create an WARNING:
WARNING: The web application [LearnJDBC] appears to have started a thread named [mysql-cj-abandoned-connection-cleanup] but has failed to stop it. This is very likely to create a memory leak. Stack trace of thread:
<see The web application [] appears to have started a thread named [Abandoned connection cleanup thread] com.mysql.jdbc.AbandonedConnectionCleanupThread >
and that answer led me to soln2.
for soln2::
put mysql-connector-java-8.0.28.jar file in the <where you install your Tomcat>/lib.
this will create an INFO:
INFO: At least one JAR was scanned for TLDs yet contained no TLDs. Enable debug logging for this logger for a complete list of JARs that were scanned but no TLDs were found in them. Skipping unneeded JARs during scanning can improve startup time and JSP compilation time.
you can just ignore it.
<see How to fix "JARs that were scanned but no TLDs were found in them " in Tomcat 9.0.0M10 >
(you should now understand what Murach’s Java Servlets and JSP was talking about: the jar in Tomcat/lib & the no need for Class.forName("com.mysql.cj.jdbc.Driver");)
to kinda fix it //-20220307_23
Tomcat 8.5. Inside catalina.properties, located in the /conf directory set:
tomcat.util.scan.StandardJarScanFilter.jarsToSkip=\*.jar
How to fix JSP compiler warning: one JAR was scanned for TLDs yet contained no TLDs?
It might be worth noting that this can also occur when Windows blocks downloads that it considers to be unsafe. This can be addressed by right-clicking the jar file (such as ojdbc7.jar), and checking the 'Unblock' box at the bottom.
Windows JAR File Properties Dialog:
As well as adding the MySQL JDBC connector ensure the context.xml (if not unpacked in the Tomcat webapps folder) with your DB connection definitions are included within Tomcats conf directory.
A very silly mistake which could be possible resulting is adding of space at the start of the JDBC URL connection.
What I mean is:-
suppose u have bymistake given the jdbc url like
String jdbcUrl=" jdbc:mysql://localhost:3306/web_customer_tracker?useSSL=false&serverTimeZone=UTC";
(Notice there is a space in the staring of the url, this will make the error)
the correct way should be:
String jdbcUrl="jdbc:mysql://localhost:3306/web_customer_tracker?useSSL=false&serverTimeZone=UTC";
(Notice no space in the staring, you may give space at the end of the url but it is safe not to)
Run java with CLASSPATH environmental variable pointing to driver's JAR file, e.g.
CLASSPATH='.:drivers/mssql-jdbc-6.2.1.jre8.jar' java ConnectURL
Where drivers/mssql-jdbc-6.2.1.jre8.jar is the path to driver file (e.g. JDBC for for SQL Server).
The ConnectURL is the sample app from that driver (samples/connections/ConnectURL.java), compiled via javac ConnectURL.java.
I was using jruby, in my case I created under config/initializers
postgres_driver.rb
$CLASSPATH << '~/.rbenv/versions/jruby-1.7.17/lib/ruby/gems/shared/gems/jdbc-postgres-9.4.1200/lib/postgresql-9.4-1200.jdbc4.jar'
or wherever your driver is, and that's it !
I had this exact issue when developing a Spring Boot application in STS, but ultimately deploying the packaged war to WebSphere(v.9). Based on previous answers my situation was unique. ojdbc8.jar was in my WEB-INF/lib folder with Parent Last class loading set, but always it says it failed to find the suitable driver.
My ultimate issue was that I was using the incorrect DataSource class because I was just following along with online tutorials/examples. Found the hint thanks to David Dai comment on his own question here: Spring JDBC Could not load JDBC driver class [oracle.jdbc.driver.OracleDriver]
Also later found spring guru example with Oracle specific driver: https://springframework.guru/configuring-spring-boot-for-oracle/
Example that throws error using org.springframework.jdbc.datasource.DriverManagerDataSource based on generic examples.
#Config
#EnableTransactionManagement
public class appDataConfig {
\* Other Bean Defs *\
#Bean
public DataSource dataSource() {
// configure and return the necessary JDBC DataSource
DriverManagerDataSource dataSource = new DriverManagerDataSource("jdbc:oracle:thin:#//HOST:PORT/SID", "user", "password");
dataSource.setSchema("MY_SCHEMA");
return dataSource;
}
}
And the corrected exapmle using a oracle.jdbc.pool.OracleDataSource:
#Config
#EnableTransactionManagement
public class appDataConfig {
/* Other Bean Defs */
#Bean
public DataSource dataSource() {
// configure and return the necessary JDBC DataSource
OracleDataSource datasource = null;
try {
datasource = new OracleDataSource();
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
datasource.setURL("jdbc:oracle:thin:#//HOST:PORT/SID");
datasource.setUser("user");
datasource.setPassword("password");
return datasource;
}
}
I was having the same issue with mysql datasource using spring data that would work outside but gave me this error when deployed on tomcat.
The error went away when I added the driver jar mysql-connector-java-8.0.16.jar to the jres lib/ext folder
However I did not want to do this in production for fear of interfering with other applications. Explicity defining the driver class solved this issue for me
spring.datasource.driver-class-name: com.mysql.cj.jdbc.Driver
You will get this same error if there is not a Resource definition provided somewhere for your app -- most likely either in the central context.xml, or individual context file in conf/Catalina/localhost. And if using individual context files, beware that Tomcat freely deletes them anytime you remove/undeploy the corresponding .war file.
For me the same error occurred while connecting to postgres while creating a dataframe from table .It was caused due to,the missing dependency. jdbc dependency was not set .I was using maven for the build ,so added the required dependency to the pom file from maven dependency
jdbc dependency
For me adding below dependency to pom.xml file just solved like magic! I had no mysql connector dependency and even adding mssql jdbc jar file to build path did not work either.
<dependency>
<groupId>com.microsoft.sqlserver</groupId>
<artifactId>mssql-jdbc</artifactId>
<version>9.4.0.jre11</version>
</dependency>
In my case I was working on a Java project with Maven and encountered this error.
In your pom.xml file make sure you have this dependencies
<dependencies>
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version>8.0.11</version>
</dependency>
</dependencies>
and where you create connection have something like this
public Connection createConnection() {
try {
String url = "jdbc:mysql://localhost:3306/yourDatabaseName";
String username = "root"; //your my sql username here
String password = "1234"; //your mysql password here
Class.forName("com.mysql.cj.jdbc.Driver");
return DriverManager.getConnection(url, username, password);
} catch (SQLException | ClassNotFoundException e) {
e.printStackTrace();
}
return null;
}
faced same issue. in my case ':' colon before '//' (jdbc:mysql://localhost:3306/dbname) was missing, and it just fixed the problem.
make sure : and // are placed properly.
I ran into the same error. In my case, the JDBC URL was correct, but the issue was with classpath. However, adding MySQL connector's JAR file to the -classpath or -cp (or, in the case of an IDE, as a library) doesn't resolve the issue. So I will have to move the JAR file to the location of Java bytecode and run java -cp :mysql_connector.jar to make this work. If someone runs into the same issue as mine, I'm leaving this here.
I encountered this issue by putting a XML file into the src/main/resources wrongly, I deleted it and then all back to normal.

JBPM: Add MySQL connector dependency to kie workbench [ver 6.2]

I'm trying to add mysql connector dependency to kie workbench. I added it by uploading the jar to the artifact repository and adding the dependency by going to project settings. When the service task that uses the connector executes, it's not able to load the mysql's Driver class. Here's more detail on how I'm using the service task - Service task using Hibernate
When the service task execute I get this message on the workbench - Unexpected error encountered : [com.sample.bpmn.hello:36 - GetData:3] -- Unable to build entity manager factory
When I look at wildfly's server.log, it seems the jar didn't get added properly - java.lang.ClassNotFoundException: Could not load requested class : com.mysql.jdbc.Driver
When I add the dependency on the workbench, I see the following warnings. I'm not able to figure out what they mean -
Verification of class com.mysql.jdbc.integration.c3p0.MysqlConnectionTester failed and will not be available for authoring. Please check the necessary external dependencies for this project are configured correctly.
Verification of class com.mysql.jdbc.integration.jboss.ExtendedMysqlExceptionSorter failed and will not be available for authoring. Please check the necessary external dependencies for this project are configured correctly.
Verification of class com.mysql.jdbc.integration.jboss.MysqlValidConnectionChecker failed and will not be available for authoring. Please check the necessary external dependencies for this project are configured correctly.
Please let me know if more info is needed.
Much appreciated.
[PS] - I must say that I just got started with hibernate as well with no prior experience. So it could be a basic thing I'm missing there.

Getting 'java.sql.SQLException: com.mysql.jdbc.Driver' with grails run-app (when BuildConfig.groovy doesn't need to be recompiled)

I've upgraded my grails application from 1.3.9 to 2.2.3 and then to 2.3.3. I read the release and upgrade notes for 1.3.9->2.2.3 and then from 2.2.3->2.3.3
I am using OpenJDK 6, Jetty 6 and the plugin jetty 1.1, MySQL 5.5 and I have the connector library under lib
Now my issue is if I run grails clean and then grails run-app the application runs without any problems but if I stop it and run grails run-app again I get a gigantic error (see here: http://pastebin.com/36MpXhir)
I also found that changing something like adding a space somewhere in BuildConfig.groovy (anything that makes it be recompiled) makes the application run normally.
Looking at the stacktrace the first thing that puzzles me is
[02.12.13 16:13:59.919] [main] pool.ConnectionPool Unable to create initial connections of pool.
java.sql.SQLException: com.mysql.jdbc.Driver
at org.apache.tomcat.jdbc.pool.PooledConnection.connectUsingDriver(PooledConnection.java:254)
at org.apache.tomcat.jdbc.pool.PooledConnection.connect(PooledConnection.java:182)
at org.apache.tomcat.jdbc.pool.ConnectionPool.createConnection(ConnectionPool.java:701)
at org.apache.tomcat.jdbc.pool.ConnectionPool.borrowConnection(ConnectionPool.java:635)
at org.apache.tomcat.jdbc.pool.ConnectionPool.init(ConnectionPool.java:486)
at org.apache.tomcat.jdbc.pool.ConnectionPool.<init>(ConnectionPool.java:144)
at org.apache.tomcat.jdbc.pool.DataSourceProxy.pCreatePool(DataSourceProxy.java:116)
at org.apache.tomcat.jdbc.pool.DataSourceProxy.createPool(DataSourceProxy.java:103)
at org.apache.tomcat.jdbc.pool.DataSourceProxy.getConnection(DataSourceProxy.java:127)
at org.springframework.jdbc.datasource.LazyConnectionDataSourceProxy.afterPropertiesSet(LazyConnectionDataSourceProxy.java:162)
There are references to org.apache.tomcat even though I'm using jetty (and removed tomcat from BuildConfig.groovy).
Did anyone else encounter such a problem?
Don't put jar files in the lib directory if they're available in a public Maven repo. It's far better to download jars once and keep them in a local cache, and reuse them as needed.
The MySQL driver is used as the commented-out example in the generated BuildConfig.groovy - just un-comment it :) You might want to bump up the version to the latest, e.g.
dependencies {
runtime 'mysql:mysql-connector-java:5.1.27'
}
This is a good site for finding Maven artifacts: http://mvnrepository.com/artifact/mysql/mysql-connector-java
If you do have a jar that's not in a Maven repo (e.g. one with shared code at your company) then you can put it in the lib directory, but it's not auto-discovered. Run grails compile --refresh-dependencies to get it added to the classpath.
For me same error has occurred while running the Grails Application.Then I debug and view the code history of my code which was committed recently.
From that I found the issue that was:
Inside the controller file I send the instance with-out properly
Eg:
**def list=[personInstance.]---> error occurred.**
**render list as JSON**
Then I correct my mistake-->clean the app --> run the app
Now its working fine.