java.net.ConnectException: Connection refused: connect: localhost

Question

I am trying to connect to h2 database from a hibernate project.

It worked fine with Oracle but I need to migrate to H2. The only things that I have changed are the driver and the hibernate.cfg.xml

pom.xml

<dependency>
    <groupId>com.h2database</groupId>
    <artifactId>h2</artifactId>
</dependency>

hibernate.cfg.xml file

<?xml version='1.0' encoding='utf-8'?>
<!DOCTYPE hibernate-configuration PUBLIC
    "-//Hibernate/Hibernate Configuration DTD 3.0//EN"
    "http://hibernate.sourceforge.net/hibernate-configuration-3.0.dtd">


<hibernate-configuration>
<session-factory>
    <property name="connection.driver_class">org.h2.Driver</property>
    <property name="connection.url">jdbc:h2:tcp://localhost/~/test;IFEXISTS=TRUE</property>
    <property name="connection.username">sa</property>
    <property name="connection.password"></property>
    <property name="connection.pool_size">1</property>
    <property name="dialect">org.hibernate.dialect.H2Dialect</property>
    <property name="current_session_context_class">thread</property>
    <property name="cache.provider_class">org.hibernate.cache.NoCacheProvider</property>
    <property name="show_sql">true</property>
    <mapping class="com.wkfsfrc.drools.dummy.runtimeload.Employee"/>
</session-factory>

the exception that I get is:

    May 19, 2015 11:32:49 AM org.hibernate.engine.jdbc.connections.internal.DriverManagerConnectionProviderImpl configure
INFO: HHH000115: Hibernate connection pool size: 1 (min=1)
Initial SessionFactory creation failed.org.hibernate.exception.JDBCConnectionException: Error calling Driver#connect

java.lang.ExceptionInInitializerError
    at com.wkfsfrc.drools.dummy.runtimeload.HibernateUtil.buildSessionFactory(HibernateUtil.java:18)
    at com.wkfsfrc.drools.dummy.runtimeload.HibernateUtil.<clinit>(HibernateUtil.java:9)
    at com.wkfsfrc.drools.dummy.runtimedataload.RuntimeDataLoadTest.<init>(RuntimeDataLoadTest.java:25)
    at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
    at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:57)
    at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
    at java.lang.reflect.Constructor.newInstance(Constructor.java:526)
    at org.junit.runners.BlockJUnit4ClassRunner.createTest(BlockJUnit4ClassRunner.java:217)
    at org.junit.runners.BlockJUnit4ClassRunner$1.runReflectiveCall(BlockJUnit4ClassRunner.java:266)
    at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12)
    at org.junit.runners.BlockJUnit4ClassRunner.methodBlock(BlockJUnit4ClassRunner.java:263)
    at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:78)
    at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:57)
    at org.junit.runners.ParentRunner$3.run(ParentRunner.java:290)
    at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:71)
    at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:288)
    at org.junit.runners.ParentRunner.access$000(ParentRunner.java:58)
    at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:268)
    at org.junit.runners.ParentRunner.run(ParentRunner.java:363)
    at org.junit.runner.JUnitCore.run(JUnitCore.java:137)
    at com.intellij.junit4.JUnit4IdeaTestRunner.startRunnerWithArgs(JUnit4IdeaTestRunner.java:74)
    at com.intellij.rt.execution.junit.JUnitStarter.prepareStreamsAndStart(JUnitStarter.java:211)
    at com.intellij.rt.execution.junit.JUnitStarter.main(JUnitStarter.java:67)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
    at com.intellij.rt.execution.application.AppMain.main(AppMain.java:134)
Caused by: org.hibernate.exception.JDBCConnectionException: Error calling Driver#connect
    at org.hibernate.engine.jdbc.connections.internal.BasicConnectionCreator$1$1.convert(BasicConnectionCreator.java:122)
    at org.hibernate.engine.jdbc.connections.internal.BasicConnectionCreator.convertSqlException(BasicConnectionCreator.java:140)
    at org.hibernate.engine.jdbc.connections.internal.DriverConnectionCreator.makeConnection(DriverConnectionCreator.java:58)
    at org.hibernate.engine.jdbc.connections.internal.BasicConnectionCreator.createConnection(BasicConnectionCreator.java:75)
    at org.hibernate.engine.jdbc.connections.internal.DriverManagerConnectionProviderImpl.configure(DriverManagerConnectionProviderImpl.java:106)
    at org.hibernate.boot.registry.internal.StandardServiceRegistryImpl.configureService(StandardServiceRegistryImpl.java:111)
    at org.hibernate.service.internal.AbstractServiceRegistryImpl.initializeService(AbstractServiceRegistryImpl.java:234)
    at org.hibernate.service.internal.AbstractServiceRegistryImpl.getService(AbstractServiceRegistryImpl.java:206)
    at org.hibernate.engine.jdbc.internal.JdbcServicesImpl.buildJdbcConnectionAccess(JdbcServicesImpl.java:260)
    at org.hibernate.engine.jdbc.internal.JdbcServicesImpl.configure(JdbcServicesImpl.java:94)
    at org.hibernate.boot.registry.internal.StandardServiceRegistryImpl.configureService(StandardServiceRegistryImpl.java:111)
    at org.hibernate.service.internal.AbstractServiceRegistryImpl.initializeService(AbstractServiceRegistryImpl.java:234)
    at org.hibernate.service.internal.AbstractServiceRegistryImpl.getService(AbstractServiceRegistryImpl.java:206)
    at org.hibernate.cfg.Configuration.buildTypeRegistrations(Configuration.java:1887)
    at org.hibernate.cfg.Configuration.buildSessionFactory(Configuration.java:1845)
    at org.hibernate.cfg.Configuration.buildSessionFactory(Configuration.java:1930)
    at com.wkfsfrc.drools.dummy.runtimeload.HibernateUtil.buildSessionFactory(HibernateUtil.java:13)
    ... 27 more
Caused by: org.h2.jdbc.JdbcSQLException: Connection is broken: "java.net.ConnectException: Connection refused: connect: localhost" [90067-178]
    at org.h2.message.DbException.getJdbcSQLException(DbException.java:344)
    at org.h2.message.DbException.get(DbException.java:167)
    at org.h2.engine.SessionRemote.connectServer(SessionRemote.java:438)
    at org.h2.engine.SessionRemote.connectEmbeddedOrServer(SessionRemote.java:315)
    at org.h2.jdbc.JdbcConnection.<init>(JdbcConnection.java:107)
    at org.h2.jdbc.JdbcConnection.<init>(JdbcConnection.java:91)
    at org.h2.Driver.connect(Driver.java:74)
    at org.hibernate.engine.jdbc.connections.internal.DriverConnectionCreator.makeConnection(DriverConnectionCreator.java:55)
    ... 41 more
Caused by: java.net.ConnectException: Connection refused: connect
    at java.net.DualStackPlainSocketImpl.waitForConnect(Native Method)
    at java.net.DualStackPlainSocketImpl.socketConnect(DualStackPlainSocketImpl.java:85)
    at java.net.AbstractPlainSocketImpl.doConnect(AbstractPlainSocketImpl.java:339)
    at java.net.AbstractPlainSocketImpl.connectToAddress(AbstractPlainSocketImpl.java:200)
    at java.net.AbstractPlainSocketImpl.connect(AbstractPlainSocketImpl.java:182)
    at java.net.PlainSocketImpl.connect(PlainSocketImpl.java:172)
    at java.net.SocksSocketImpl.connect(SocksSocketImpl.java:392)
    at java.net.Socket.connect(Socket.java:579)
    at org.h2.util.NetUtils.createSocket(NetUtils.java:123)
    at org.h2.util.NetUtils.createSocket(NetUtils.java:103)
    at org.h2.engine.SessionRemote.initTransfer(SessionRemote.java:100)
    at org.h2.engine.SessionRemote.connectServer(SessionRemote.java:434)
    ... 46 more

What else do I need to do, to successfully connect to H2.

Do I need to start H2 before connecting to it or Hibernate does this? DONO

Any advice is appreciated!

Answer 1

You seem not to have started the H2 server. Based on your URL, you're using tcp connection, ie the server has to be started first.

2 ways out:

• you have a java master program in which you should start the server like this:

org.h2.tools.Server.createTcpServer().start();

• or you could start it manually prior to your connection attempt like this:

java -cp h2*.jar org.h2.tools.Server

I noticed you're using ifexists=true. Connection will still be refused if the database does not exist prior to connection.