validation certificate agains cacert

Dear programmers,

I would like to ask you if there is any way how to compare certificate
against cacerts file.
I have already loaded certificate in keystore like:

      CertificateFactory cf = CertificateFactory.getInstance("X.509");
      String filename = System.getProperty("java.home")+"/lib/security/
cacerts".replace('/', File.separatorChar);
      System.out.println(filename);
      FileInputStream in = new FileInputStream(filename);
      BufferedInputStream bis = new BufferedInputStream(in);
      KeyStore keystore =
KeyStore.getInstance(KeyStore.getDefaultType());
      String pwd = "changeit";
      keystore.load(in, pwd.toCharArray());

Is there any way how to validate certificate in TrustManager.
My TrustManager is:
        System.out.println("Initialization of Trust Manager");
        trustManager = new TrustManager[] {
            new X509TrustManager()
            {
                //X509TrustManager sunJSSEX509TrustManager;
                public java.security.cert.X509Certificate[]
getAcceptedIssuers() {
                    System.out.println("InitializeTrustManager:
getAcceptedIssuers:");
                    //return
sunJSSEX509TrustManager.getAcceptedIssuers();
                    return null;
                }

                public void
checkClientTrusted( java.security.cert.X509Certificate[] certs, String
authType)
                {
                    for(int j=0;j<certs.length;j++)
                    {
                        System.out.println("initializeTrustmanager:
checkClientTrusted:" + certs[j] + " authTyp:" + authType);
                        System.out.println(" Subject DN:
"+certs[j].getSubjectDN());
                        System.out.println(" Issuer DN:
"+certs[j].getIssuerDN());
                        System.out.println(" Serial number:
"+certs[j].getSerialNumber());

                    }
                }

                public void checkServerTrusted
( java.security.cert.X509Certificate[] certs, String authType) throws
java.security.cert.CertificateException {
                    for(int i=0;i<certs.length;i++)
                    {
                        X509Certificate x509Certificate = certs[i];
                        System.out.println("InitializeTrustManager:
checkServerTrusted:" +
x509Certificate.getIssuerX500Principal().getName()+"AuthTyp:" +
authType);
                        System.out.println("InitializeTrustManager:
checkServerTrusted:" + x509Certificate.getIssuerDN());

                    }

                }
                public boolean isClientTrusted(X509Certificate[] arg0)
throws CertificateException
                {
                    System.out.println("InitializeTrustManager:
isClientTrusted: ");
                    return true;
                }
                public boolean isServerTrusted(X509Certificate[] arg0)
throws CertificateException
                {
                    for(int i=0;i<arg0.length;i++)
                    {
                        System.out.println("InitializeTrustManager:
isServerTrusted: "+ arg0[i].getIssuerDN());
                    }
                    //TODO
                    return true;
                }
            }
        };

Thank you in advance
Petr