When I press "Save" button I get an exception like that ;

javax.servlet.ServletException: org.hibernate.exception.JDBCConnectionException: Cannot open connection javax.faces.webapp.FacesServlet.service(FacesServlet.java:325)

root cause

javax.faces.el.EvaluationException: org.hibernate.exception.JDBCConnectionException: Cannot open connection javax.faces.component.MethodBindingMethodExpressionAdapter.invoke(MethodBindingMethodExpressionAdapter.java:102) com.sun.faces.application.ActionListenerImpl.processAction(ActionListenerImpl.java:102) javax.faces.component.UICommand.broadcast(UICommand.java:315) javax.faces.component.UIViewRoot.broadcastEvents(UIViewRoot.java:775) javax.faces.component.UIViewRoot.processApplication(UIViewRoot.java:1267) com.sun.faces.lifecycle.InvokeApplicationPhase.execute(InvokeApplicationPhase.java:82) com.sun.faces.lifecycle.Phase.doPhase(Phase.java:101) com.sun.faces.lifecycle.LifecycleImpl.execute(LifecycleImpl.java:118) javax.faces.webapp.FacesServlet.service(FacesServlet.java:312)

root cause

org.hibernate.exception.JDBCConnectionException: Cannot open connection org.hibernate.exception.SQLStateConverter.convert(SQLStateConverter.java:98) org.hibernate.exception.JDBCExceptionHelper.convert(JDBCExceptionHelper.java:66) org.hibernate.exception.JDBCExceptionHelper.convert(JDBCExceptionHelper.java:52) org.hibernate.jdbc.ConnectionManager.openConnection(ConnectionManager.java:449) org.hibernate.jdbc.ConnectionManager.getConnection(ConnectionManager.java:167) org.hibernate.jdbc.JDBCContext.connection(JDBCContext.java:142) org.hibernate.transaction.JDBCTransaction.begin(JDBCTransaction.java:85) org.hibernate.impl.SessionImpl.beginTransaction(SessionImpl.java:1463) 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.hibernate.context.ThreadLocalSessionContext$TransactionProtectionWrapper.invoke(ThreadLocalSessionContext.java:344) $Proxy108.beginTransaction(Unknown Source) com.yemex.beans.CompanyBean.saveOrUpdate(CompanyBean.java:52) 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.apache.el.parser.AstValue.invoke(AstValue.java:196) org.apache.el.MethodExpressionImpl.invoke(MethodExpressionImpl.java:276) com.sun.faces.facelets.el.TagMethodExpression.invoke(TagMethodExpression.java:98) javax.faces.component.MethodBindingMethodExpressionAdapter.invoke(MethodBindingMethodExpressionAdapter.java:88) com.sun.faces.application.ActionListenerImpl.processAction(ActionListenerImpl.java:102) javax.faces.component.UICommand.broadcast(UICommand.java:315) javax.faces.component.UIViewRoot.broadcastEvents(UIViewRoot.java:775) javax.faces.component.UIViewRoot.processApplication(UIViewRoot.java:1267) com.sun.faces.lifecycle.InvokeApplicationPhase.execute(InvokeApplicationPhase.java:82) com.sun.faces.lifecycle.Phase.doPhase(Phase.java:101) com.sun.faces.lifecycle.LifecycleImpl.execute(LifecycleImpl.java:118) javax.faces.webapp.FacesServlet.service(FacesServlet.java:312)

root cause

java.sql.SQLException: No suitable driver found for jdbc:postgresql://localhost/postgres java.sql.DriverManager.getConnection(Unknown Source) java.sql.DriverManager.getConnection(Unknown Source) org.hibernate.connection.DriverManagerConnectionProvider.getConnection(DriverManagerConnectionProvider.java:133) org.hibernate.jdbc.ConnectionManager.openConnection(ConnectionManager.java:446) org.hibernate.jdbc.ConnectionManager.getConnection(ConnectionManager.java:167) org.hibernate.jdbc.JDBCContext.connection(JDBCContext.java:142) org.hibernate.transaction.JDBCTransaction.begin(JDBCTransaction.java:85) org.hibernate.impl.SessionImpl.beginTransaction(SessionImpl.java:1463) 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.hibernate.context.ThreadLocalSessionContext$TransactionProtectionWrapper.invoke(ThreadLocalSessionContext.java:344) $Proxy108.beginTransaction(Unknown Source) com.yemex.beans.CompanyBean.saveOrUpdate(CompanyBean.java:52) 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.apache.el.parser.AstValue.invoke(AstValue.java:196) org.apache.el.MethodExpressionImpl.invoke(MethodExpressionImpl.java:276) com.sun.faces.facelets.el.TagMethodExpression.invoke(TagMethodExpression.java:98) javax.faces.component.MethodBindingMethodExpressionAdapter.invoke(MethodBindingMethodExpressionAdapter.java:88) com.sun.faces.application.ActionListenerImpl.processAction(ActionListenerImpl.java:102) javax.faces.component.UICommand.broadcast(UICommand.java:315) javax.faces.component.UIViewRoot.broadcastEvents(UIViewRoot.java:775) javax.faces.component.UIViewRoot.processApplication(UIViewRoot.java:1267) com.sun.faces.lifecycle.InvokeApplicationPhase.execute(InvokeApplicationPhase.java:82) com.sun.faces.lifecycle.Phase.doPhase(Phase.java:101) com.sun.faces.lifecycle.LifecycleImpl.execute(LifecycleImpl.java:118) javax.faces.webapp.FacesServlet.service(FacesServlet.java:312)