title: UnknownHostException when trying to connect to heroku-postgres from local Springboot project with Spring JPA
body: <p>I am trying to connect to heroku-postgres with Spring JPA when I am getting an unknownHostException.</p>
  
  <pre><code>    at org.postgresql.core.v3.ConnectionFactoryImpl.openConnectionImpl(ConnectionFactoryImpl.java:292) ~[postgresql-42.2.5.jar:42.2.5]
      at org.postgresql.core.ConnectionFactory.openConnection(ConnectionFactory.java:49) ~[postgresql-42.2.5.jar:42.2.5]
      at org.postgresql.jdbc.PgConnection.&lt;init&gt;(PgConnection.java:195) ~[postgresql-42.2.5.jar:42.2.5]
      at org.postgresql.Driver.makeConnection(Driver.java:454) ~[postgresql-42.2.5.jar:42.2.5]
      at org.postgresql.Driver.connect(Driver.java:256) ~[postgresql-42.2.5.jar:42.2.5]
      at com.zaxxer.hikari.util.DriverDataSource.getConnection(DriverDataSource.java:136) ~[HikariCP-3.2.0.jar:na]
      at com.zaxxer.hikari.pool.PoolBase.newConnection(PoolBase.java:369) ~[HikariCP-3.2.0.jar:na]
      at com.zaxxer.hikari.pool.PoolBase.newPoolEntry(PoolBase.java:198) ~[HikariCP-3.2.0.jar:na]
      at com.zaxxer.hikari.pool.HikariPool.createPoolEntry(HikariPool.java:467) [HikariCP-3.2.0.jar:na]
      at com.zaxxer.hikari.pool.HikariPool.checkFailFast(HikariPool.java:541) [HikariCP-3.2.0.jar:na]
      at com.zaxxer.hikari.pool.HikariPool.&lt;init&gt;(HikariPool.java:115) [HikariCP-3.2.0.jar:na]
      at com.zaxxer.hikari.HikariDataSource.getConnection(HikariDataSource.java:112) [HikariCP-3.2.0.jar:na]
      at org.springframework.jdbc.datasource.DataSourceUtils.fetchConnection(DataSourceUtils.java:157) [spring-jdbc-5.1.7.RELEASE.jar:5.1.7.RELEASE]
      at org.springframework.jdbc.datasource.DataSourceUtils.doGetConnection(DataSourceUtils.java:115) [spring-jdbc-5.1.7.RELEASE.jar:5.1.7.RELEASE]
      at org.springframework.jdbc.datasource.DataSourceUtils.getConnection(DataSourceUtils.java:78) [spring-jdbc-5.1.7.RELEASE.jar:5.1.7.RELEASE]
      at org.springframework.jdbc.support.JdbcUtils.extractDatabaseMetaData(JdbcUtils.java:319) [spring-jdbc-5.1.7.RELEASE.jar:5.1.7.RELEASE]
      at org.springframework.jdbc.support.JdbcUtils.extractDatabaseMetaData(JdbcUtils.java:356) [spring-jdbc-5.1.7.RELEASE.jar:5.1.7.RELEASE]
      at org.springframework.boot.autoconfigure.orm.jpa.DatabaseLookup.getDatabase(DatabaseLookup.java:73) [spring-boot-autoconfigure-2.1.5.RELEASE.jar:2.1.5.RELEASE]
      at org.springframework.boot.autoconfigure.orm.jpa.JpaProperties.determineDatabase(JpaProperties.java:142) [spring-boot-autoconfigure-2.1.5.RELEASE.jar:2.1.5.RELEASE]
      at org.springframework.boot.autoconfigure.orm.jpa.JpaBaseConfiguration.jpaVendorAdapter(JpaBaseConfiguration.java:113) [spring-boot-autoconfigure-2.1.5.RELEASE.jar:2.1.5.RELEASE]
      at org.springframework.boot.autoconfigure.orm.jpa.HibernateJpaConfiguration$$EnhancerBySpringCGLIB$$cd9cadec.CGLIB$jpaVendorAdapter$7(&lt;generated&gt;) [spring-boot-autoconfigure-2.1.5.RELEASE.jar:2.1.5.RELEASE]
      at org.springframework.boot.autoconfigure.orm.jpa.HibernateJpaConfiguration$$EnhancerBySpringCGLIB$$cd9cadec$$FastClassBySpringCGLIB$$bb47839b.invoke(&lt;generated&gt;) [spring-boot-autoconfigure-2.1.5.RELEASE.jar:2.1.5.RELEASE]
      at org.springframework.cglib.proxy.MethodProxy.invokeSuper(MethodProxy.java:244) [spring-core-5.1.7.RELEASE.jar:5.1.7.RELEASE]
      at org.springframework.context.annotation.ConfigurationClassEnhancer$BeanMethodInterceptor.intercept(ConfigurationClassEnhancer.java:363) [spring-context-5.1.7.RELEASE.jar:5.1.7.RELEASE]
      at org.springframework.boot.autoconfigure.orm.jpa.HibernateJpaConfiguration$$EnhancerBySpringCGLIB$$cd9cadec.jpaVendorAdapter(&lt;generated&gt;) [spring-boot-autoconfigure-2.1.5.RELEASE.jar:2.1.5.RELEASE]
      at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:1.8.0_171]
      at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[na:1.8.0_171]
      at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:1.8.0_171]
      at java.lang.reflect.Method.invoke(Method.java:498) ~[na:1.8.0_171]
      at org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:154) [spring-beans-5.1.7.RELEASE.jar:5.1.7.RELEASE]
      at org.springframework.beans.factory.support.ConstructorResolver.instantiate(ConstructorResolver.java:622) [spring-beans-5.1.7.RELEASE.jar:5.1.7.RELEASE]
      at org.springframework.beans.factory.support.ConstructorResolver.instantiateUsingFactoryMethod(ConstructorResolver.java:456) [spring-beans-5.1.7.RELEASE.jar:5.1.7.RELEASE]
      at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateUsingFactoryMethod(AbstractAutowireCapableBeanFactory.java:1321) [spring-beans-5.1.7.RELEASE.jar:5.1.7.RELEASE]
      at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:1160) [spring-beans-5.1.7.RELEASE.jar:5.1.7.RELEASE]
      at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:555) [spring-beans-5.1.7.RELEASE.jar:5.1.7.RELEASE]
      at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:515) [spring-beans-5.1.7.RELEASE.jar:5.1.7.RELEASE]
      at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:320) [spring-beans-5.1.7.RELEASE.jar:5.1.7.RELEASE]
      at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:222) ~[spring-beans-5.1.7.RELEASE.jar:5.1.7.RELEASE]
      at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:318) [spring-beans-5.1.7.RELEASE.jar:5.1.7.RELEASE]
      at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:199) [spring-beans-5.1.7.RELEASE.jar:5.1.7.RELEASE]
      at org.springframework.beans.factory.config.DependencyDescriptor.resolveCandidate(DependencyDescriptor.java:277) ~[spring-beans-5.1.7.RELEASE.jar:5.1.7.RELEASE]
      at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:1248) ~[spring-beans-5.1.7.RELEASE.jar:5.1.7.RELEASE]
      at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:1168) ~[spring-beans-5.1.7.RELEASE.jar:5.1.7.RELEASE]
      at org.springframework.beans.factory.support.ConstructorResolver.resolveAutowiredArgument(ConstructorResolver.java:857) [spring-beans-5.1.7.RELEASE.jar:5.1.7.RELEASE]
      at org.springframework.beans.factory.support.ConstructorResolver.createArgumentArray(ConstructorResolver.java:760) [spring-beans-5.1.7.RELEASE.jar:5.1.7.RELEASE]
      at org.springframework.beans.factory.support.ConstructorResolver.instantiateUsingFactoryMethod(ConstructorResolver.java:509) [spring-beans-5.1.7.RELEASE.jar:5.1.7.RELEASE]
      at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateUsingFactoryMethod(AbstractAutowireCapableBeanFactory.java:1321) [spring-beans-5.1.7.RELEASE.jar:5.1.7.RELEASE]
      at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:1160) [spring-beans-5.1.7.RELEASE.jar:5.1.7.RELEASE]
      at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:555) [spring-beans-5.1.7.RELEASE.jar:5.1.7.RELEASE]
      at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:515) [spring-beans-5.1.7.RELEASE.jar:5.1.7.RELEASE]
      at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:320) [spring-beans-5.1.7.RELEASE.jar:5.1.7.RELEASE]
      at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:222) ~[spring-beans-5.1.7.RELEASE.jar:5.1.7.RELEASE]
      at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:318) [spring-beans-5.1.7.RELEASE.jar:5.1.7.RELEASE]
      at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:199) [spring-beans-5.1.7.RELEASE.jar:5.1.7.RELEASE]
      at org.springframework.beans.factory.config.DependencyDescriptor.resolveCandidate(DependencyDescriptor.java:277) ~[spring-beans-5.1.7.RELEASE.jar:5.1.7.RELEASE]
      at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:1248) ~[spring-beans-5.1.7.RELEASE.jar:5.1.7.RELEASE]
      at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:1168) ~[spring-beans-5.1.7.RELEASE.jar:5.1.7.RELEASE]
      at org.springframework.beans.factory.support.ConstructorResolver.resolveAutowiredArgument(ConstructorResolver.java:857) [spring-beans-5.1.7.RELEASE.jar:5.1.7.RELEASE]
      at org.springframework.beans.factory.support.ConstructorResolver.createArgumentArray(ConstructorResolver.java:760) [spring-beans-5.1.7.RELEASE.jar:5.1.7.RELEASE]
      at org.springframework.beans.factory.support.ConstructorResolver.instantiateUsingFactoryMethod(ConstructorResolver.java:509) [spring-beans-5.1.7.RELEASE.jar:5.1.7.RELEASE]
      at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateUsingFactoryMethod(AbstractAutowireCapableBeanFactory.java:1321) [spring-beans-5.1.7.RELEASE.jar:5.1.7.RELEASE]
      at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:1160) [spring-beans-5.1.7.RELEASE.jar:5.1.7.RELEASE]
      at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:555) [spring-beans-5.1.7.RELEASE.jar:5.1.7.RELEASE]
      at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:515) [spring-beans-5.1.7.RELEASE.jar:5.1.7.RELEASE]
      at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:320) [spring-beans-5.1.7.RELEASE.jar:5.1.7.RELEASE]
      at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:222) ~[spring-beans-5.1.7.RELEASE.jar:5.1.7.RELEASE]
      at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:318) [spring-beans-5.1.7.RELEASE.jar:5.1.7.RELEASE]
      at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:199) [spring-beans-5.1.7.RELEASE.jar:5.1.7.RELEASE]
      at org.springframework.context.support.AbstractApplicationContext.getBean(AbstractApplicationContext.java:1105) ~[spring-context-5.1.7.RELEASE.jar:5.1.7.RELEASE]
      at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:867) ~[spring-context-5.1.7.RELEASE.jar:5.1.7.RELEASE]
      at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:549) ~[spring-context-5.1.7.RELEASE.jar:5.1.7.RELEASE]
      at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.refresh(ServletWebServerApplicationContext.java:142) ~[spring-boot-2.1.5.RELEASE.jar:2.1.5.RELEASE]
      at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:775) ~[spring-boot-2.1.5.RELEASE.jar:2.1.5.RELEASE]
      at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:397) ~[spring-boot-2.1.5.RELEASE.jar:2.1.5.RELEASE]
      at org.springframework.boot.SpringApplication.run(SpringApplication.java:316) ~[spring-boot-2.1.5.RELEASE.jar:2.1.5.RELEASE]
      at org.springframework.boot.SpringApplication.run(SpringApplication.java:1260) ~[spring-boot-2.1.5.RELEASE.jar:2.1.5.RELEASE]
      at org.springframework.boot.SpringApplication.run(SpringApplication.java:1248) ~[spring-boot-2.1.5.RELEASE.jar:2.1.5.RELEASE]
      at com.aquatic.fish.encyclopedia.aquaticfishdb.AquaticFishDbApplication.main(AquaticFishDbApplication.java:16) ~[classes/:na]
  Caused by: java.net.UnknownHostException: [ADDRESS REMOVED FOR SECURITY REASONS].eu-west-1.compute.amazonaws.com
      at java.net.AbstractPlainSocketImpl.connect(AbstractPlainSocketImpl.java:184) ~[na:1.8.0_171]
      at java.net.PlainSocketImpl.connect(PlainSocketImpl.java:172) ~[na:1.8.0_171]
      at java.net.SocksSocketImpl.connect(SocksSocketImpl.java:392) ~[na:1.8.0_171]
      at java.net.Socket.connect(Socket.java:589) ~[na:1.8.0_171]
      at org.postgresql.core.PGStream.&lt;init&gt;(PGStream.java:70) ~[postgresql-42.2.5.jar:42.2.5]
      at org.postgresql.core.v3.ConnectionFactoryImpl.tryConnect(ConnectionFactoryImpl.java:91) ~[postgresql-42.2.5.jar:42.2.5]
      at org.postgresql.core.v3.ConnectionFactoryImpl.openConnectionImpl(ConnectionFactoryImpl.java:192) ~[postgresql-42.2.5.jar:42.2.5]
  </code></pre>
  
  <ul>
  <li>The DB is up and running on Heroku, I was able to connect to it with pgAdmin4.</li>
  <li>I checked the credentials in heroku and cross-referenced with my application.yml file, they match up.</li>
  <li>I set my DB URL as a system property as per <a href="https://help.heroku.com/HV3GBIAA/why-can-t-my-java-spring-app-cannot-connect-to-my-database" rel="nofollow noreferrer">https://help.heroku.com/HV3GBIAA/why-can-t-my-java-spring-app-cannot-connect-to-my-database</a></li>
  <li>If I hit the endpoint I created to access the DB, I get a 500: Unable to acquire JDBC Connection; nested exception is org.hibernate.exception.JDBCConnectionException: Unable to acquire JDBC Connection, but this is expected given the above issue.</li>
  </ul>
  
  <p><em>application.yml</em></p>
  
  <pre><code>  datasource:
      username: [removed for security reasons, matches up with the one in heroku]
      password: [removed for security reasons, matches up with the one in heroku]
      url: jdbc:postgresql://[username]:[password]@___-__-___-__-__.eu-west-1.compute.amazonaws.com:5432/_________
      driver-class-name: org.postgresql.Driver
      hikari:
        maximum-pool-size: 10
  
    jpa:
      database-platform: org.hibernate.dialect.PostgreSQLDialect
  </code></pre>
  
  <p>I am expecting to be able to connect to heroku postgres instead of using a postgres db locally. I was able to connect to the very same DB with pgAdmin4, but I am not able to connect the app to my spring boot project, despite (I believe) the configurations are correct in the .yml file.</p>
  
  <p>Thank you!</p>