I am getting below error in Spring Application with Hibernate. I have just upgraded the database mysql version from 5.6 to 8.0.
The Error is:
nested exception is org.hibernate.HibernateException: Dialect class not found: org.hibernate.dialect.MySQL8Dialect
In my build.gredle file I have included the following:
dependencies {
compile group: 'mysql', name: 'mysql-connector-java', version: '8.0.11'
}
And in my applicationContext.xml file I have included the following:
<property name="hibernateProperties">
<props>
<prop key="hibernate.dialect">org.hibernate.dialect.MySQL8Dialect</prop>
<prop key="hibernate.show_sql">true</prop>
<prop key="hibernate.jdbc.batch_size">20</prop>
</props>
</property>
In my lib folder I have the connector also "mysql-connector-java-8.0.11.jar".
I don't understand why the dialect is still missing. Please help. :)
I was using Hibernate v-3.3.0 which actually dose not support the specified dialect. The reference link of the specified hibernate version is (https://javadoc.io/doc/org.hibernate/hibernate-core/3.3.0.CR1/index.html). Thanks to M. Deinum(https://stackoverflow.com/users/2696260/m-deinum) for helping me finding the issue.
Related
I have seen this question posted a few times on StackOverflow, and it has been with mostly Spring Boot apps with Spring Boot Configuration. I've followed all the steps, and I still have this issue. If I can't get this resolved soon, I will have to go back to the old java.util.Date in order to persist my data to the database ... at least it worked without issues. So, I have a Spring 5.1.2.Release app, with Hibernate 5.4.0.Final, the hibernate-java8 dependency, and the latest MySQL Connector 8.0.13.
I understand from previous posts and other articles on the Net that if the database is set for UTC, but the App is running in another timezone, in my case GMT-5 for EST, then this problem might pop up.
So, here are the technical details:
My MySQL connection looks like:
hibernate.connection.url=jdbc:mysql://localhost:3306/my_db?
serverTimezone=UTC&useLegacyDatetimeCode=false&useTimezone=true
The connection string, is used in the applicationContext.xml:
<bean id="dataSource"
class="org.springframework.jdbc.datasource.DriverManagerDataSource">
<property name="driverClassName">
<value>${hibernate.connection.driver.class}</value>
</property>
<property name="url">
<value>${hibernate.connection.url}</value>
</property>
<property name="username">
<value>${hibernate.connection.username}</value>
</property>
<property name="password">
<value>${hibernate.connection.password}</value>
</property>
</bean>
My Hibernate properties in my applicationContext.xml look like:
<property name="hibernateProperties">
<props>
<prop key="hibernate.dialect">${hibernate.dialect}</prop>
<prop key="hibernate.show_sql">${hibernate.show_sql}</prop>
<prop key="hibernate.cglib.use_reflection_optimizer">${hibernate.cglib.use_reflection_optimizer}</prop>
<prop key="useUnicode">true</prop>
<prop key="useLegacyDatetimeCode">false</prop>
<prop key="serverTimezone">UTC</prop>
<prop key="useTimezone">true</prop>
<prop key="hibernate.jdbc.time_zone">UTC</prop>
</props>
</property>
My Maven dependencies are:
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version>8.0.13</version>
</dependency>
<dependency>
<groupId>org.hibernate</groupId>
<artifactId>hibernate-core</artifactId>
<version>5.4.0.Final</version>
</dependency>
<dependency>
<groupId>org.hibernate</groupId>
<artifactId>hibernate-java8</artifactId>
<version>5.4.0.Final</version>
</dependency>
My Entity Code is simple:
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
#Column(name = "transaction_id")
private long txId;
#Column(name = "transaction_date")
private LocalDate txDate;
I save my code to the database like this:
#Override
public TxEntity create(TxEntity txEntity)
{
this.sessionFactory.getCurrentSession().save(txEntity);
this.sessionFactory.getCurrentSession().flush();
this.sessionFactory.getCurrentSession().refresh(txEntity);
return txEntity;
}
The database has "transaction_date" as a DATE field in MySQL.
My Unit Test shows that I can create a new record, and I have set the date as follows:
LocalDate today = LocalDate.now();
I persist the record, and when I test:
assertEquals(today, myRecord.getTransactionDate());
this fails, because I get the previous date.
I thought that if I used the latest versions of Hibernate and the Hibernate-java8 I would be fine, but that's not the case. I thought if I pulled in the latest JPA2.2 that would work, but it's not. So, I think I am doing everything right, and I still have an issue.
So, if there is anything you need to see, let me know and I can add it. I think I am doing everything right, but if there is anything off I need to fix, please let me know. And of course, I'll keep looking at this myself.
If you don't want to touch your Java project or connection strings to solve this issue you can configure the MySQL timezone directly. On my computer the JVM timezone was correct (America/Sao_Paulo), so changing it to UTC in order to solve this conflict with MySQL was a no go.
The problem I had was just at the MySQL timezone configuration. Since I run MySQL on a container it got a wrong default timezone. The fix was to pass the --default-time-zone=America/Sao_Paulo to the MySQL container configuration, which fixed this issue. Now both MySQL and JVM got the same timezone.
For me, after some debugging for some time, I noticed Mysql timezone was UTC, but my default jvm timezone which can be seen by:
public class DefaultTimeZone {
public static void main(String[] args) {
System.out.println(java.util.TimeZone.getDefault().getID());
}
}
was America/Montreal so in updated my ide (IntellJ) settings to pass -Duser.timezone=UTC as a parameter when starting the application. (Of course there are so many other ways to do this, but in my case this was enough)
I am using Spring 3.0.5, Hibernate 3.6.7, Atomikos TransactionEssentials 3.7.0 and MySQL 5.5
I recently faced the problem, that connections in my connectionpool timedout after 8 hours and were reset by the server causing a message "resume for XID '???' raised 0: unknown
Here is my datasource configuration:
<bean id="myDataSource"
class="com.atomikos.jdbc.AtomikosDataSourceBean"
init-method="init"
destroy-method="close"
depends-on="myConfigurer">
<property name="uniqueResourceName" value="myPUDataSource" />
<property name="xaDataSourceClassName" value="$CONF{database.XAdriver}" />
<property name="poolSize" value="10" />
<property name="xaProperties">
<props>
<prop key="user">$CONF{database.user}</prop>
<prop key="password">$CONF{database.password}</prop>
<prop key="URL">$CONF{database.url}</prop>
<prop key="pinGlobalTxToPhysicalConnection">true</prop>
<prop key="autoReconnect">true</prop>
</props>
</property>
</bean>
As I was investigating I found out that the option autoReconnect=true only reconnects my faulted connection after a delay of 2 seconds (which is configurabe I think).
Browsing the web I found solutions suggesting to increase wait_timeout in the MySQL-Server, which I think is not a real solution.
The application should be able to handle dead connections and reconnect automatically, because there may be other issues causing a connection loss, too.
(And I don't want to make any directives to Servers whatever kind the application uses).
At last I found a good solution for this, which I will post as answer to help people facing the same or similar problems.
By inserting the line:
<property name="testQuery" value="SELECT 1"/>
on the data source's configuration, it seems the connection is tested before use and reconnected if it's dead.
I tried it with wait_timeout=60 and even with a restart of the MySQL-Server while my application was running...
Result: no more Exceptions and Errors!
I getting an error when running my program. the error is: org.hibernate.HibernateException: JDBC Driver class not found: com.mysql.jdbc.Driver.
The driver is there...I am not sure what it causing this. Any suggestions?
<hibernate-configuration>
<session-factory>
<property name="hibernate.dialect">org.hibernate.dialect.MySQLDialect</property>
<property name="hibernate.connection.url">jdbc:mysql://localhost:3306/registrar</property>
<property name="hibernate.connection.username">root</property>
<property name="hibernate.connection.password">root</property>
<property name="hibernate.connection.driver_class">com.mysql.jdbc.Driver</property>
<mapping resource="com/ths/entity/Course.hbm.xml"/>
<mapping resource="com/ths/entity/Student.hbm.xml"/>
<mapping resource="com/ths/entity/Enrollment.hbm.xml"/>
</session-factory>
</hibernate-configuration>
The driver is there...I am not sure what it causing this.
The driver is not there. The error is simple: the Java VM couldn't find your driver. So, double-check the classpath. If you are deploying a web-application, make sure your driver is in the server's lib, and not in WEB-INF/lib.
You may have that jar in project but class loader is unable to find that as class loader does not check each and every folder of project. If it is a web application then you need to put jar file in WEB-INF/LIB.
If it is a standalone application then you need to add jar file in build path.
you can check class path during run time to see whether folder (where jar exist) is considered in class path or not.
I am not sure what was causing this. I was trying this on my work computer. I tried it at home and it worked fine. Must just be a setting.
I am a beginer with visual studio 2008 (C#), mysql and NHibernate.
I have problems with mysql connector as I don't know how to add reference to it.
In my project I have:
/lib/mysql-connector-net-6.1.4-src/
(downloaded from http://dev.mysql.com/downloads/mirror.php?id=387799#mirrors)
Now I right click on my project -> addReference -> browse -> What now?
Should I also edit my hibernate configuration?
<hibernate-configuration xmlns="urn:nhibernate-configuration-2.2">
<session-factory>
<property name="connection.provider">NHibernate.Connection.DriverConnectionProvider</property>
<property name="connection.driver_class">NHibernate.Driver.MySqlDataDriver</property>
<property name="connection.connection_string">Server=localhost;database=Pets;Database=pets,User ID=root,Password=;</property>
<property name="dialect">NHibernate.Dialect.MySQL5Dialect</property>
<property name="proxyfactory.factory_class"> NHibernate.ByteCode.LinFu.ProxyFactoryFactory, NHibernate.ByteCode.LinFu </property>
<property name="show_sql">false</property>
</session-factory>
</hibernate-configuration>
Thanks
You need to add a reference to the MySQL connector DLL that corresponds to the version of .NET you are targeting.
From the link provided, it seems like you downloaded the source code for the MySQL connector, so you'll either need to build this code and take the desired DLL out of the /bin folder afterwards or download a full installer (which will include the binaries) from the second link here:
http://dev.mysql.com/downloads/connector/net/6.1.html
Once you add this DLL to your project, you'll need to edit that NHibernate configuration to update the "connection.connection_string" property with the connection string for your database.
Hope this helps. There is some more documentation available here:
http://dev.mysql.com/doc/refman/5.1/en/connector-net.html
I'm using Spring 3.0.2, Hibernate 3.5.0 and c3p0 0.9.1.2 and I'm having a ton of errors when it comes down to retrieving connections and commiting transactions. Here's my configuration of c3p0:
<bean id="dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource" destroy-method="close">
<property name="driverClass" value="${jdbc.driverClassName}"/>
<property name="jdbcUrl" value="${jdbc.url}"/>
<property name="properties">
<props>
<prop key="c3p0.acquireIncrement">5</prop>
<prop key="c3p0.maxIdleTime">30</prop>
<prop key="c3p0.idleConnectionTestPeriod">20</prop>
<prop key="c3p0.maxPoolSize">100</prop>
<prop key="c3p0.maxStatements">0</prop>
<prop key="c3p0.minPoolSize">1</prop>
<prop key="user">${jdbc.username}</prop>
<prop key="password">${jdbc.password}</prop>
</props>
</property>
</bean>
Up until recently I got this error pretty often:
com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: Communications link failure
Last packet sent to the server was 0 ms ago.
Recently I also get these:
com.mysql.jdbc.exceptions.jdbc4.MySQLNonTransientConnectionException: Connection.close() has already been called. Invalid operation in this state.
java.sql.SQLException: Connections could not be acquired from the underlying database!
Any suggestions?
That's probably because connections are being timed out. Checkout idle_test_period setting or use bonecp http://jolbox.com which has sensible defaults instead.