Connection refused when trying to connect to mysql using hibernate - java

I am trying to connect to mysql database using hibernate from the cfg file as
<?xml version='1.0' encoding='utf-8'?>
<!DOCTYPE hibernate-configuration PUBLIC "-//Hibernate/Hibernate Configuration DTD//EN"
"http://hibernate.sourceforge.net/hibernate-configuration-3.0.dtd">
<hibernate-configuration>
<session-factory>
<property name="hibernate.connection.driver_class">
com.mysql.jdbc.Driver</property>
<property name="hibernate.connection.url">
jdbc:mysql://localhost:3306/test</property>
<property name="hibernate.connection.username">
root</property>
<property name="hibernate.connection.password">
root</property>
<property name="hibernate.connection.pool_size">
10</property>
<property name="show_sql">true</property>
<property name="dialect">
org.hibernate.dialect.MySQLDialect</property>
<property name="hibernate.hbm2ddl.auto">
update</property>
<!-- Mapping files -->
<mapping resource="Employee.hbm.xml" />
</session-factory>
</hibernate-configuration>
private static SessionFactory factory;
public static void main(String[] args) {
try {
factory = new Configuration().configure().buildSessionFactory();
} catch (Throwable ex) {
System.err.println("Failed to create sessionFactory object." + ex);
ex.fillInStackTrace();
ex.printStackTrace();
throw new ExceptionInInitializerError(ex);
}
Though my connection-string,username,password are correct and the same are working fine in other project with basic jdbc connection, But when I try it using hibernate I am getting this error on console
Exception in thread "main" java.lang.ExceptionInInitializerError
at com.hibernate.ManageEmployee.main(ManageEmployee.java:21)
Caused by: org.hibernate.HibernateException: Could not parse configuration: /hibernate.cfg.xml
at com.hibernate.ManageEmployee.main(ManageEmployee.java:19)
Caused by: org.dom4j.DocumentException: Connection refused: connect Nested exception: Connection refused: connect
at org.dom4j.io.SAXReader.read(SAXReader.java:484)
at org.hibernate.cfg.Configuration.doConfigure(Configuration.java:1481)
at org.hibernate.cfg.Configuration.configure(Configuration.java:1425)
at org.hibernate.cfg.Configuration.configure(Configuration.java:1411)
at com.hibernate.ManageEmployee.main(ManageEmployee.java:16)
And yes the database server is up and running but the connections from this hibernate application are refused

The problem is that the xml parser is trying to access the schema file which is specified in the configuration file. Can the box, where you are running your program, access the internet?
Here is some additional information:
https://forum.hibernate.org/viewtopic.php?f=1&t=949031

Related

Anybody can check for me what wrong when I try to connect PostgreSQL by using Hibernate

First, let me list the things I have used:
Eclipse JEE version 2021-03
Apache Tomcat Server 9
Hibernate ORM version 5.2.18.Final
PostgreSQL 14
Java 8
Some driver I have used: the required in lib of Hibernate ORM, postgresql-42.2.22.jar, jaxb-api-1.0.jar
Second is my code:
In the main class, I use it to run the application I let the name of class is CreateStudentDemo in the phucldh.Demo package in the src folder
public static void main(String[] args) {
// create session factory
SessionFactory factory = new Configuration().configure("hibernate.cfg.xml").addAnnotatedClass(Student.class).buildSessionFactory();
// create session
Session session = factory.getCurrentSession();
try {
// create a student object
Student tempStudent = new Student("Le", "Phuc", "phucldh.work#gmail.com");
// start a transaction
session.beginTransaction();
// save the student object
session.save(tempStudent);
// commit transaction
session.getTransaction().commit();
} catch (Exception e) {
System.out.println("Create student demo error: " + e.getMessage());
} finally {
factory.close();
}
}
And to connect to PostgreSQL I have a configuration file hibernate.cfg.xml in the src folder and the content of this file:
<session-factory>
<!-- JDBC Database connection settings -->
<property name="connection.driver_class">org.postgresql.Driver</property>
<property name="connection.url">jdbc:postgresql://localhost:5432/HibernateLearn</property>
<property name="connection.username">postgres</property>
<property name="connection.password">********</property>
<!-- JDBC connection pool settings ... using built-in test pool -->
<property name="connection.pool_size">1</property>
<!-- Select our SQL dialect -->
<property name="hibernate.dialect">org.hibernate.dialect.PostgreSQLDialect</property>
<!-- Set the current session context -->
<property name="current_session_context_class">thread</property>
<!-- Disable the second-level cache -->
<property name="cache.provider_class">org.hibernate.cache.internal.NoCacheProvider</property>
<!-- Echo the SQL to stdout -->
<property name="show_sql">true</property>
<!-- Drop and re-create the database schema on startup -->
<property name="hbm2ddl.auto">create</property>
</session-factory>
That all I have done but when I running I have a problem:
INFO: HHH000206: hibernate.properties not found
Exception in thread "main" java.lang.NoSuchMethodError: 'javax.xml.bind.JAXBContext javax.xml.bind.JAXBContext.newInstance(java.lang.Class[])'
at org.hibernate.boot.cfgxml.internal.JaxbCfgProcessor.unmarshal(JaxbCfgProcessor.java:122)
at org.hibernate.boot.cfgxml.internal.JaxbCfgProcessor.unmarshal(JaxbCfgProcessor.java:65)
at org.hibernate.boot.cfgxml.internal.ConfigLoader.loadConfigXmlResource(ConfigLoader.java:57)
at org.hibernate.boot.registry.StandardServiceRegistryBuilder.configure(StandardServiceRegistryBuilder.java:163)
at org.hibernate.cfg.Configuration.configure(Configuration.java:258)
at phucldh.Demo.CreateStudentDemo.main(CreateStudentDemo.java:15)
And I see that line 15 of CreateStudentDemo.java is the line about
SessionFactory factory = new Configuration().configure("hibernate.cfg.xml").addAnnotatedClass(Student.class).buildSessionFactory();
So I hope that anybody can help me find what I have wrong. Thank everybody very much. Hope all have a nice day.

How to use SSL encryption when connecting Vaadin App with Hibernate to MariaDB on Azure

I am currently working on a Java 8 app with Vaadin and Hibernate which I am trying to migrate to Azure for testing purposes.
Everything worked out so far except for one thing:
When I activate the require SSL option in The MariaDB on Azure, I can't connect anymore:
Caused by: java.sql.SQLException: SSL connection is required. Please specify SSL options and retry.
Unfortunately I didn't write this app myself and I am not too familiar with neither Vaadin nor Hibernate or even Java in general and how to establish ssl or db connections with those.So I need some help:
This is the JDBC Connection string in the Servlet.java file, where for my understanding the db init happens:
Connection con = DriverManager.getConnection("jdbc:mysql://<username>.mariadb.database.azure.com:3306/<db>?autoReconnect=true", "<username>", "<password>");
which I changed by just adding this to the URL: &useSSL=true&requireSSL=true&verifyServerCertificate=true
Now the app doesn't stop at the DB init anymore but still crashes before the page is fully rendered, with the same error message.
I found a hibernate.cfg.xml with the following content (I removed the mappings to keep it shorter):
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE hibernate-configuration PUBLIC "-//Hibernate/Hibernate Configuration DTD 3.0//EN"
"http://www.hibernate.org/dtd/hibernate-configuration-3.0.dtd">
<hibernate-configuration>
<session-factory>
<!-- Hibernate -->
<property name="hibernate.use_sql_comments">true</property>
<property name="hibernate.format_sql">true</property>
<property name="hibernate.show_sql">false</property>
<property name="hibernate.connection.autocommit">true</property>
<property name="hibernate.dialect">org.hibernate.dialect.MySQLInnoDBDialect</property>
<!-- Hikari -->
<property name="hibernate.connection.provider_class">com.zaxxer.hikari.hibernate.HikariConnectionProvider</property>
<property name="hibernate.hikari.dataSourceClassName">com.mysql.jdbc.jdbc2.optional.MysqlDataSource</property>
<property name="hibernate.hikari.dataSource.url">jdbc:mysql://dbname.mariadb.database.azure.com:3306/db</property>
<property name="hibernate.hikari.dataSource.user">username</property>
<property name="hibernate.hikari.dataSource.password">password</property>
<property name="hibernate.hikari.dataSource.cachePrepStmts">true</property>
<property name="hibernate.hikari.dataSource.prepStmtCacheSize">250</property>
<property name="hibernate.hikari.dataSource.prepStmtCacheSqlLimit">2048</property>
<property name="hibernate.hikari.dataSource.useServerPrepStmts">true</property>
</session-factory>
</hibernate-configuration>
What do I have to change there to make use of SSL for the connection?
You may try:
<property name="hibernate.hikari.dataSource.url">jdbc:mysql://dbname.mariadb.database.azure.com:3306/db?useSSL=true</property>
Per my understanding, the properties in hibernate.cfg.xml will finally be used to generate a whole connection string. So, if there is no direct property for useSSL, you may add it to the url manually.

Hibernate - Could not load requested class : org.mariadb.jdbc.Driver

So my issues is pretty basic. I'm just running a simple hibernate web application that sends a new entry to my SQL MariaDB. When I run the application I get an error message saying the requested class could not be loaded. What doesn't make sense is I have the .jar files in my library and my other test file runs fine. For this project I'm using Intellij IDEA.
hibernate.cfg.xml
<!DOCTYPE hibernate-configuration PUBLIC
"-//Hibernate/Hibernate Configuration DTD 3.0//EN"
"http://www.hibernate.org/dtd/hibernate-configuration-3.0.dtd">
<hibernate-configuration>
<session-factory>
<!-- JDBC Database connection settings -->
<property name="connection.driver_class">com.mariadb.jdbc.Driver</property>
<property name="connection.url">jdbc:mariadb://localhost:3306/hb_student_tracker</property>
<property name="connection.username">hbstudent</property>
<property name="connection.password"></property>
<!-- JDBC connection pool settings ... using built-in test pool -->
<property name="connection.pool_size">1</property>
<!-- Select our SQL dialect -->
<property name="dialect">org.hibernate.dialect.MariaDB53Dialect</property>
<!-- Echo the SQL to stdout -->
<property name="show_sql">true</property>
<!-- Set the current session context -->
<property name="current_session_context_class">thread</property>
</session-factory>
CreateStudentDemo
import com.luv2code.hibernate.demo.entity.Student;
import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.cfg.Configuration;
public class CreateStudentDemo {
public static void main(String[] args) {
//create session factory
SessionFactory factory = new Configuration()
.configure("hibernate.cfg.xml")
.addAnnotatedClass(Student.class)
.buildSessionFactory();
// create session
Session session = factory.getCurrentSession();
try {
// create a student object
System.out.println("Creating new student object...");
Student tempStudent = new Student(
"Paul", "Wall", "paul#luv2code.com");
// start a transaction
session.beginTransaction();
// save the student object
System.out.println("Saving the student...");
session.save(tempStudent);
// commit transaction
session.getTransaction().commit();
System.out.println("Done!");
}
finally {
factory.close();
}
}
I'm thinking the issue lies with the hibernate.xml file. Any help would be appreciated!
com.mariadb.jdbc.Driver
Could not load requested class : org.mariadb.jdbc.Driver

Java SQL "syntax error or access violation"

I'm trying to learn how to use Java hibernate with mysql, and I'm having troubles running the example I've downloaded.
I'm getting the following error:
Exception in thread "main" org.hibernate.exception.GenericJDBCException: Cannot open connection
at org.hibernate.exception.ErrorCodeConverter.handledNonSpecificException(ErrorCodeConverter.java:92)
at org.hibernate.exception.ErrorCodeConverter.convert(ErrorCodeConverter.java:80)
....
at org.hibernate.persister.entity.BasicEntityPersister.insert...
**Caused by: java.sql.SQLException: Syntax error or access violation message from server: "Access denied for user 'web'#'localhost' to database 'hibernatetutorial'"**
at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:1997)
...
at org.hibernate.connection.DriverManagerConnectionProvider.getConnectio...
My configuration file includes the following code:
<?xml version='1.0' encoding='utf-8'?>
<!DOCTYPE hibernate-configuration PUBLIC
"-//Hibernate/Hibernate Configuration DTD//EN"
"http://hibernate.sourceforge.net/hibernate-configuration-3.0.dtd">
<hibernate-configuration>
<session-factory>
<property name="hibernate.connection.driver_class">com.mysql.jdbc.Driver</property>
<property name="hibernate.connection.url">jdbc:mysql://localhost/hibernatetutorial</property>
<property name="hibernate.connection.username">web</property>
<property name="hibernate.connection.password">web</property>
<property name="hibernate.connection.pool_size">10</property>
<property name="show_sql">true</property>
<property name="dialect">org.hibernate.dialect.MySQLDialect</property>
<property name="hibernate.hbm2ddl.auto">update</property>
<!-- Mapping files -->
<mapping resource="contact.hbm.xml"/>
</session-factory>
</hibernate-configuration>
and the main function (which was downloaded from: http://www.roseindia.net/hibernate/runninge-xample.shtml) includes the following code:
public static void main(String[] args) {
Session session = null;
try{
// This step will read hibernate.cfg.xml and prepare hibernate for use
SessionFactory sessionFactory = new Configuration().configure().buildSessionFactory();
session =sessionFactory.openSession();
//Create new instance of Contact and set values in it by reading them from form object
System.out.println("Inserting Record");
Contact contact = new Contact();
contact.setId(6);
contact.setFirstName("Deepak");
contact.setLastName("Kumar");
contact.setEmail("deepak_38#yahoo.com");
session.save(contact);
System.out.println("Done");
}catch(Exception e){
System.out.println(e.getMessage());
}finally{
// Actual contact insertion will happen at this step
session.flush();
session.close();
}
I've created the new "web" user with all the required permissions using:
CREATE USER 'web'#'localhost' IDENTIFIED BY 'web';
GRANT ALL PRIVILEGES ON hibernatetutorial.* TO web#localhost IDENTIFIED BY 'web';
And I've created the "hibernatetutorial" database.
Any idea what I'm doing wrong? I don't even know how to debug this.
Thanks,
Li
ON mydb.* TO web#localhost
shouldnt it be
ON hibernatetutorial.* TO web#localhost

What can I do with "Could not parse configuration" error from Hibernate?

I am following Java Hibernate tutorial example from YouTube. Everything looks great until I try to run code which is supposed to create table Employee on Apache Derby server. I tried to use SQL server (2008) first and I was getting the same error.
Could not parse configuration: hibernate.cfg.xml and there is also timeout error. I appreciate any help. Thanks.
Here is the error I get:
17:28:51,574 INFO Version:15 - Hibernate Annotations 3.4.0.GA
17:28:51,587 INFO Environment:560 - Hibernate 3.3.2.GA
17:28:51,590 INFO Environment:593 - hibernate.properties not found
17:28:51,594 INFO Environment:771 - Bytecode provider name : javassist
17:28:51,597 INFO Environment:652 - using JDK 1.4 java.sql.Timestamp handling
17:28:51,648 INFO Version:14 - Hibernate Commons Annotations 3.1.0.GA
17:28:51,655 INFO Configuration:1474 - configuring from resource: hibernate.cfg.xml
17:28:51,655 INFO Configuration:1451 - Configuration resource: hibernate.cfg.xml
17:28:51,702 DEBUG DTDEntityResolver:64 - trying to resolve system-id [http://www.hibernate.org/dtd/hibernate-configuration-3.0.dtd]
Exception in thread "main" org.hibernate.HibernateException: Could not parse configuration: hibernate.cfg.xml
at org.hibernate.cfg.Configuration.doConfigure(Configuration.java:1542)
at org.hibernate.cfg.AnnotationConfiguration.doConfigure(AnnotationConfiguration.java:1035)
at org.hibernate.cfg.AnnotationConfiguration.doConfigure(AnnotationConfiguration.java:64)
at org.hibernate.cfg.Configuration.configure(Configuration.java:1476)
at org.hibernate.cfg.AnnotationConfiguration.configure(AnnotationConfiguration.java:1017)
at com.hibernate.chapter1.TestEmployee.main(TestEmployee.java:14)
Caused by: org.dom4j.DocumentException: Connection timed out: connect Nested exception: Connection timed out: connect
at org.dom4j.io.SAXReader.read(SAXReader.java:484)
at org.hibernate.cfg.Configuration.doConfigure(Configuration.java:1532)
... 5 more
Here is my hibernate.cfg.xml file:
<?xml version='1.0' encoding='utf-8'?>
<!DOCTYPE hibernate-configuration PUBLIC
"-//Hibernate/Hibernate Configuration DTD 3.0//EN"
"http://www.hibernate.org/dtd/hibernate-configuration-3.0.dtd">
<hibernate-configuration>
<session-factory>
<!-- Database connection settings -->
<property name="connection.driver_class">org.apache.derby.jdbc.ClientDriver</property>
<property name="connection.url">jdbc:derby://localhost:1527/HibernateDb;create=true</property>
<property name="connection.username">user</property>
<property name="connection.password">password</property>
<!-- JDBC connection pool (use the built-in) -->
<property name="connection.pool_size">2</property>
<!-- SQL dialect -->
<property name="dialect">org.hibernate.dialect.DerbyDialect</property>
<!-- Enable Hibernate's current session context -->
<property name="current_session_context_class">thread</property>
<!-- Disable the second-level cache -->
<property name="cache.provider_class">org.hibernate.cache.NoCacheProvider</property>
<!-- Echo all executed SQL to stdout -->
<property name="show_sql">true</property>
<!-- Drop and re-create the database schema on startup -->
<property name="hbm2ddl.auto">create</property>
</session-factory>
</hibernate-configuration>
And, here is the code I am running:
package com.hibernate.chapter1;
import org.hibernate.cfg.AnnotationConfiguration;
import org.hibernate.tool.hbm2ddl.SchemaExport;
public class TestEmployee {
public static void main(String[] args) {
AnnotationConfiguration config = new AnnotationConfiguration();
config.addAnnotatedClass(Employee.class);
config.configure("hibernate.cfg.xml");
new SchemaExport(config).create(true, true);
}
}
What did I do wrong?
This means the hibernate.dtd cannot be resolved - its resolution is attempted on the server. The dtd is contained in the jars files - see here and here for how to resolve it.

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