Unable to make JDBC Connection

问题:

I am creating web API project using Jersey and Hibernate. When I tried yesterday all worked well. Today it started showing "Unable to make JDBC connection" error. I tried all possible ways to check it. Still I am not able to resolve it. Any help would be highly appreciated.

I am creating the session as follows:

SessionFactory sessionFactory;
ServiceRegistry serviceRegistry;
Configuration configuration = new Configuration();
configuration.configure("hibernate.cfg.xml");
serviceRegistry = new ServiceRegistryBuilder().applySettings(
            configuration.getProperties()).build();
sessionFactory = configuration.buildSessionFactory(serviceRegistry);
Session session = sessionFactory.openSession();

And here is my database connection settings

<!--  Database connection settings  -->
<property name="connection.driver_class">com.mysql.jdbc.Driver</property>
<property name="connection.url">jdbc:mysql//127.0.0.1/sampleDB</property>
<property name="dialect">org.hibernate.dialect.MySQLDialect</property>

Below is the stack trace of the exception:

javax.servlet.ServletException: org.hibernate.HibernateException: Unable to make JDBC Connection [jdbc:mysql//127.0.0.1/sampleDB]
    org.glassfish.jersey.servlet.WebComponent.service(WebComponent.java:393)
    org.glassfish.jersey.servlet.ServletContainer.service(ServletContainer.java:381)
    org.glassfish.jersey.servlet.ServletContainer.service(ServletContainer.java:344)
    org.glassfish.jersey.servlet.ServletContainer.service(ServletContainer.java:221)


root cause 

org.hibernate.HibernateException: Unable to make JDBC Connection [jdbc:mysql//127.0.0.1/sampleDB]
    org.hibernate.engine.jdbc.connections.internal.BasicConnectionCreator.createConnection(BasicConnectionCreator.java:77)
    org.hibernate.engine.jdbc.connections.internal.DriverManagerConnectionProviderImpl.configure(DriverManagerConnectionProviderImpl.java:106)
    org.hibernate.boot.registry.internal.StandardServiceRegistryImpl.configureService(StandardServiceRegistryImpl.java:111)
    org.hibernate.service.internal.AbstractServiceRegistryImpl.initializeService(AbstractServiceRegistryImpl.java:234)
    org.hibernate.service.internal.AbstractServiceRegistryImpl.getService(AbstractServiceRegistryImpl.java:206)
    org.hibernate.engine.jdbc.internal.JdbcServicesImpl.buildJdbcConnectionAccess(JdbcServicesImpl.java:260)
    org.hibernate.engine.jdbc.internal.JdbcServicesImpl.configure(JdbcServicesImpl.java:94)
    org.hibernate.boot.registry.internal.StandardServiceRegistryImpl.configureService(StandardServiceRegistryImpl.java:111)
    org.hibernate.service.internal.AbstractServiceRegistryImpl.initializeService(AbstractServiceRegistryImpl.java:234)
    org.hibernate.service.internal.AbstractServiceRegistryImpl.getService(AbstractServiceRegistryImpl.java:206)
    org.hibernate.cfg.Configuration.buildTypeRegistrations(Configuration.java:1887)
    org.hibernate.cfg.Configuration.buildSessionFactory(Configuration.java:1845)
    com.ps.rs.controller.Hello.sayHtmlHello(Hello.java:93)
    sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
    sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
    java.lang.reflect.Method.invoke(Unknown Source)
    org.glassfish.jersey.server.model.internal.ResourceMethodInvocationHandlerFactory$1.invoke(ResourceMethodInvocationHandlerFactory.java:81)
    org.glassfish.jersey.server.model.internal.AbstractJavaResourceMethodDispatcher$1.run(AbstractJavaResourceMethodDispatcher.java:151)
    org.glassfish.jersey.server.model.internal.AbstractJavaResourceMethodDispatcher.invoke(AbstractJavaResourceMethodDispatcher.java:171)
    org.glassfish.jersey.server.model.internal.JavaResourceMethodDispatcherProvider$TypeOutInvoker.doDispatch(JavaResourceMethodDispatcherProvider.java:195)
    org.glassfish.jersey.server.model.internal.AbstractJavaResourceMethodDispatcher.dispatch(AbstractJavaResourceMethodDispatcher.java:104)
    org.glassfish.jersey.server.model.ResourceMethodInvoker.invoke(ResourceMethodInvoker.java:384)
    org.glassfish.jersey.server.model.ResourceMethodInvoker.apply(ResourceMethodInvoker.java:342)
    org.glassfish.jersey.server.model.ResourceMethodInvoker.apply(ResourceMethodInvoker.java:101)
    org.glassfish.jersey.server.ServerRuntime$1.run(ServerRuntime.java:271)
    org.glassfish.jersey.internal.Errors$1.call(Errors.java:271)
    org.glassfish.jersey.internal.Errors$1.call(Errors.java:267)
    org.glassfish.jersey.internal.Errors.process(Errors.java:315)
    org.glassfish.jersey.internal.Errors.process(Errors.java:297)
    org.glassfish.jersey.internal.Errors.process(Errors.java:267)
    org.glassfish.jersey.process.internal.RequestScope.runInScope(RequestScope.java:297)
    org.glassfish.jersey.server.ServerRuntime.process(ServerRuntime.java:254)
    org.glassfish.jersey.server.ApplicationHandler.handle(ApplicationHandler.java:1030)
    org.glassfish.jersey.servlet.WebComponent.service(WebComponent.java:373)
    org.glassfish.jersey.servlet.ServletContainer.service(ServletContainer.java:381)
    org.glassfish.jersey.servlet.ServletContainer.service(ServletContainer.java:344)
    org.glassfish.jersey.servlet.ServletContainer.service(ServletContainer.java:221)

回答1:

This may help you

Also add username and password

<property name="hibernate.dialect">org.hibernate.dialect.MySQLDialect</property>
   <property name="hibernate.connection.driver_class">com.mysql.jdbc.Driver</property>
   <property name="hibernate.connection.url">jdbc:mysql://localhost:3306/sampleDB</property>
   <property name="hibernate.connection.username">yourUserNameForMysql</property>
   <property name="hibernate.connection.password">passwordForMySql</property>

After Mysql 5.x use org.hibernate.dialect.MySQL5Dialect class

<property name="hibernate.dialect">org.hibernate.dialect.MySQL5Dialect</property>
   <property name="hibernate.connection.driver_class">com.mysql.jdbc.Driver</property>
   <property name="hibernate.connection.url">jdbc:mysql://localhost:3306/sampleDB</property>
   <property name="hibernate.connection.username">yourUserNameForMysql</property>
   <property name="hibernate.connection.password">passwordForMySql</property>

回答2:

change this line

<property name="connection.url">jdbc:mysql//localhost/sampleDB</property>

to

<property name="connection.url">jdbc:mysql//localhost:3306/sampleDB</property>

and you should be through as you are missing port in connection url. Yopu are also missing

<property name="hibernate.connection.username">

   </property>
   <property name="hibernate.connection.password">

   </property>