java https stacktrace

java.lang.IllegalStateException: Failed to execute CommandLineRunner
	at org.springframework.boot.SpringApplication.callRunner(SpringApplication.java:803)
	at org.springframework.boot.SpringApplication.callRunners(SpringApplication.java:784)
	at org.springframework.boot.SpringApplication.afterRefresh(SpringApplication.java:771)
	at org.springframework.boot.SpringApplication.run(SpringApplication.java:307)
	at org.springframework.boot.SpringApplication.run(SpringApplication.java:1185)
	at org.springframework.boot.SpringApplication.run(SpringApplication.java:1174)
	at com.thebooks.Application.main(Application.java:39)
Caused by: org.springframework.web.client.ResourceAccessException: I/O error on GET request for "https://api-sandbox.rabobank.nl/openapi/sandbox/oauth2/authorize?client_id=a049bbf2-fa09-4aa0-a576-8446d6d53789&response_type=code&scope=ais.balances.read":sun.security.validator.ValidatorException: PKIX path building failed: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target; nested exception is javax.net.ssl.SSLHandshakeException: sun.security.validator.ValidatorException: PKIX path building failed: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target
	at org.springframework.web.client.RestTemplate.doExecute(RestTemplate.java:582)
	at org.springframework.web.client.RestTemplate.execute(RestTemplate.java:532)
	at org.springframework.web.client.RestTemplate.getForEntity(RestTemplate.java:264)
	at com.thebooks.httpclient.HttpClient.run(HttpClient.java:25)
	at org.springframework.boot.SpringApplication.callRunner(SpringApplication.java:800)
	... 6 more
Caused by: javax.net.ssl.SSLHandshakeException: sun.security.validator.ValidatorException: PKIX path building failed: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target
	at sun.security.ssl.Alerts.getSSLException(Unknown Source)
	at sun.security.ssl.SSLSocketImpl.fatal(Unknown Source)
	at sun.security.ssl.Handshaker.fatalSE(Unknown Source)
	at sun.security.ssl.Handshaker.fatalSE(Unknown Source)
	at sun.security.ssl.ClientHandshaker.serverCertificate(Unknown Source)
	at sun.security.ssl.ClientHandshaker.processMessage(Unknown Source)
	at sun.security.ssl.Handshaker.processLoop(Unknown Source)
	at sun.security.ssl.Handshaker.process_record(Unknown Source)
	at sun.security.ssl.SSLSocketImpl.readRecord(Unknown Source)
	at sun.security.ssl.SSLSocketImpl.performInitialHandshake(Unknown Source)
	at sun.security.ssl.SSLSocketImpl.startHandshake(Unknown Source)
	at sun.security.ssl.SSLSocketImpl.startHandshake(Unknown Source)
	at sun.net.www.protocol.https.HttpsClient.afterConnect(Unknown Source)
	at sun.net.www.protocol.https.AbstractDelegateHttpsURLConnection.connect(Unknown Source)
	at sun.net.www.protocol.https.HttpsURLConnectionImpl.connect(Unknown Source)
	at org.springframework.http.client.SimpleBufferingClientHttpRequest.executeInternal(SimpleBufferingClientHttpRequest.java:81)
	at org.springframework.http.client.AbstractBufferingClientHttpRequest.executeInternal(AbstractBufferingClientHttpRequest.java:48)
	at org.springframework.http.client.AbstractClientHttpRequest.execute(AbstractClientHttpRequest.java:53)
	at org.springframework.web.client.RestTemplate.doExecute(RestTemplate.java:571)
	... 10 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 sun.security.validator.PKIXValidator.doBuild(Unknown Source)
	at sun.security.validator.PKIXValidator.engineValidate(Unknown Source)
	at sun.security.validator.Validator.validate(Unknown Source)
	at sun.security.ssl.X509TrustManagerImpl.validate(Unknown Source)
	at sun.security.ssl.X509TrustManagerImpl.checkTrusted(Unknown Source)
	at sun.security.ssl.X509TrustManagerImpl.checkServerTrusted(Unknown Source)
	... 25 more
Caused by: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target
	at sun.security.provider.certpath.SunCertPathBuilder.build(Unknown Source)
	at sun.security.provider.certpath.SunCertPathBuilder.engineBuild(Unknown Source)
	at java.security.cert.CertPathBuilder.build(Unknown Source)
	... 31 more