Styjun

UPDATED

Can't connect to a postgres database. The dependency of postgres is added via maven.

Maven dependency

<dependency>
 <groupId>postgresql</groupId>
 <artifactId>postgresql</artifactId>
 <version>9.1-901-1.jdbc4</version>
</dependency>

Postgres Pool

public class PostgresDB implements DBPool 
public PostgresDB() 


private static ComboPooledDataSource comboPooledDataSource = new ComboPooledDataSource();

static 
 try 
 Properties props = new Properties();
 props.setProperty("ssl", "false");
 comboPooledDataSource.setDriverClass( "org.postgresql.Driver" );
 comboPooledDataSource.setJdbcUrl("jdbc:postgresql://ec2-79-125-4-72.eu-west-1.compute.amazonaws.com:5432/d35hi5u7rnue7f");
 comboPooledDataSource.setUser("user");
 comboPooledDataSource.setPassword("xxxxxxxx");
 comboPooledDataSource.setProperties(props);
 catch (Exception e) 
 System.out.println("Error");
 // handle the exception
 


public Connection getConnection() throws SQLException 
 return comboPooledDataSource.getConnection();

Code for get a Connection

Connection connection = PostgresDB.getConnection();

Error

WARNING: com.mchange.v2.resourcepool.BasicResourcePool$AcquireTask@2326357e -- Acquisition Attempt Failed!!! Clearing pending acquires. While trying to acquire a needed new resource, we failed to succeed more than the maximum number of allowed acquisition attempts (30). Last acquisition attempt exception: org.postgresql.util.PSQLException: Der Verbindungsversuch schlug fehl. at org.postgresql.core.v3.ConnectionFactoryImpl.openConnectionImpl(ConnectionFactoryImpl.java:152) at org.postgresql.core.ConnectionFactory.openConnection(ConnectionFactory.java:66) at org.postgresql.jdbc2.AbstractJdbc2Connection.(AbstractJdbc2Connection.java:125) at org.postgresql.jdbc3.AbstractJdbc3Connection.(AbstractJdbc3Connection.java:30) at org.postgresql.jdbc3g.AbstractJdbc3gConnection.(AbstractJdbc3gConnection.java:22) at org.postgresql.jdbc4.AbstractJdbc4Connection.(AbstractJdbc4Connection.java:32) at org.postgresql.jdbc4.Jdbc4Connection.(Jdbc4Connection.java:24) at org.postgresql.Driver.makeConnection(Driver.java:393) at org.postgresql.Driver.connect(Driver.java:267) at com.mchange.v2.c3p0.DriverManagerDataSource.getConnection(DriverManagerDataSource.java:119) at com.mchange.v2.c3p0.WrapperConnectionPoolDataSource.getPooledConnection(WrapperConnectionPoolDataSource.java:143) at com.mchange.v2.c3p0.WrapperConnectionPoolDataSource.getPooledConnection(WrapperConnectionPoolDataSource.java:132) at com.mchange.v2.c3p0.impl.C3P0PooledConnectionPool$1PooledConnectionResourcePoolManager.acquireResource(C3P0PooledConnectionPool.java:137) at com.mchange.v2.resourcepool.BasicResourcePool.doAcquire(BasicResourcePool.java:1014) at com.mchange.v2.resourcepool.BasicResourcePool.access$800(BasicResourcePool.java:32) at com.mchange.v2.resourcepool.BasicResourcePool$AcquireTask.run(BasicResourcePool.java:1810) at com.mchange.v2.async.ThreadPoolAsynchronousRunner$PoolThread.run(ThreadPoolAsynchronousRunner.java:547) Caused by: javax.net.ssl.SSLHandshakeException: PKIX path building failed: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target at java.base/sun.security.ssl.Alert.createSSLException(Alert.java:128) at java.base/sun.security.ssl.TransportContext.fatal(TransportContext.java:321) at java.base/sun.security.ssl.TransportContext.fatal(TransportContext.java:264) at java.base/sun.security.ssl.TransportContext.fatal(TransportContext.java:259) at java.base/sun.security.ssl.CertificateMessage$T12CertificateConsumer.checkServerCerts(CertificateMessage.java:642) at java.base/sun.security.ssl.CertificateMessage$T12CertificateConsumer.onCertificate(CertificateMessage.java:461) at java.base/sun.security.ssl.CertificateMessage$T12CertificateConsumer.consume(CertificateMessage.java:361) at java.base/sun.security.ssl.SSLHandshake.consume(SSLHandshake.java:392) at java.base/sun.security.ssl.HandshakeContext.dispatch(HandshakeContext.java:444) at java.base/sun.security.ssl.HandshakeContext.dispatch(HandshakeContext.java:421) at java.base/sun.security.ssl.TransportContext.dispatch(TransportContext.java:178) at java.base/sun.security.ssl.SSLTransport.decode(SSLTransport.java:164) at java.base/sun.security.ssl.SSLSocketImpl.decode(SSLSocketImpl.java:1152) at java.base/sun.security.ssl.SSLSocketImpl.readHandshakeRecord(SSLSocketImpl.java:1063) at java.base/sun.security.ssl.SSLSocketImpl.startHandshake(SSLSocketImpl.java:402) at java.base/sun.security.ssl.SSLSocketImpl.ensureNegotiated(SSLSocketImpl.java:716) at java.base/sun.security.ssl.SSLSocketImpl$AppOutputStream.write(SSLSocketImpl.java:970) at java.base/java.io.BufferedOutputStream.flushBuffer(BufferedOutputStream.java:81) at java.base/java.io.BufferedOutputStream.flush(BufferedOutputStream.java:142) at org.postgresql.core.PGStream.flush(PGStream.java:523) at org.postgresql.core.v3.ConnectionFactoryImpl.sendStartupPacket(ConnectionFactoryImpl.java:259) at org.postgresql.core.v3.ConnectionFactoryImpl.openConnectionImpl(ConnectionFactoryImpl.java:105)
... 16 more
Caused by: sun.security.validator.ValidatorException: PKIX path building failed: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target at java.base/sun.security.validator.PKIXValidator.doBuild(PKIXValidator.java:385) at java.base/sun.security.validator.PKIXValidator.engineValidate(PKIXValidator.java:290) at java.base/sun.security.validator.Validator.validate(Validator.java:264) at java.base/sun.security.ssl.X509TrustManagerImpl.validate(X509TrustManagerImpl.java:321) at java.base/sun.security.ssl.X509TrustManagerImpl.checkTrusted(X509TrustManagerImpl.java:221) at java.base/sun.security.ssl.X509TrustManagerImpl.checkServerTrusted(X509TrustManagerImpl.java:129) at java.base/sun.security.ssl.CertificateMessage$T12CertificateConsumer.checkServerCerts(CertificateMessage.java:626)
... 33 more
Caused by: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target at java.base/sun.security.provider.certpath.SunCertPathBuilder.build(SunCertPathBuilder.java:141) at java.base/sun.security.provider.certpath.SunCertPathBuilder.engineBuild(SunCertPathBuilder.java:126) at java.base/java.security.cert.CertPathBuilder.build(CertPathBuilder.java:297) at java.base/sun.security.validator.PKIXValidator.doBuild(PKIXValidator.java:380) ... 39 more

Fix

If you have the same problem change the code to this:

comboPooledDataSource.setJdbcUrl("jdbc:postgresql://url:port/database");

Properties props = new Properties();
props.setProperty("sslmode", "require");
props.setProperty("ssl", "true");
props.setProperty("sslfactory", "org.postgresql.ssl.NonValidatingFactory");
props.setProperty("user", "username");
props.setProperty("password", "xxxxxxx");
comboPooledDataSource.setProperties(props);

Instead of props.setProperty("ssl", "false"); try:

props.setProperty("sslmode", "disable");

For more info see Heroku's docs on Connecting to Relational Databases on Heroku with Java.