PKIX path building failed while invoking OKTA API for access token.

Hello,

we are getting below error while invoking API for access token from our code.

Wealready have imported required certificate in Java home.

Error is PKIX path building failed: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target

javax.net.ssl.SSLHandshakeException: PKIX path building failed: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target.

We are trying to test OpenID connect integration through OKTA. Below is the required code snippet.

HttpPost httppost = new HttpPost("https://dev-15411581.okta.com/oauth2/v1/token");

         httppost.setHeader("content-type", "application/x-www-form-urlencoded");

          postParameters = new ArrayList<NameValuePair>();

          postParameters.add(new BasicNameValuePair("grant_type", "authorization_code"));

          postParameters.add(new BasicNameValuePair("code", code));

          postParameters.add(new BasicNameValuePair("redirect_uri", "http://localhost:8080/Inside"));

          postParameters.add(new BasicNameValuePair("client_id", "0oa60ln2uiYjJWHBM5d7"));

          postParameters.add(new BasicNameValuePair("client_secret", "LDYhkim1E-PhqTu3lH0KIqHgsa9C-vdzxSvtjSQw"));

          postParameters.add(new BasicNameValuePair("code_verifier", "qjrzSW9gMiUgpUvqgEPE4_-8swvyCtfOVvg55o5S_es"));

          httppost.setEntity(new UrlEncodedFormEntity(postParameters, "UTF-8"));

Regards

Mihir