java通过ssl连接mqtt

at sun.security.x509.X509CertImpl.(Unknown Source)

at sun.security.provider.X509Factory.engineGenerateCertificate(Unknown Source)

at java.security.cert.CertificateFactory.generateCertificate(Unknown Source)

at com.test.mqtt.AppTest.main(AppTest.java:51)

at sun.security.util.DerValue.init(Unknown Source)

at sun.security.util.DerValue.(Unknown Source)

at sun.security.util.DerValue.(Unknown Source)

... 4 more

    try {

        cf = CertificateFactory.getInstance("X.509");

         FileInputStream crtIn = new FileInputStream("D:\\test\\client.crt");

         X509Certificate caCert = (X509Certificate) cf.generateCertificate(crtIn);

            //Certificate caCert =  cf.generateCertificate(crtIn);

            crtIn.close();

    } catch (CertificateException e) {

        // TODO Auto-generated catch block

        e.printStackTrace();

    }