Server certificate validation on client side

Dear developers,

I have one question regarding server certificate validation in java on
the client side.
All my communication goes over SSL.
I would like to validate server certificate because of Man In the
Midle attact on the client side.

I would like to check whether server certificate is correct.

My actual code is:

      System.out.println("Initialization of trust Manager");
      initializeTrustManager();
      System.out.println("Initialization of SSL Context");
      initializeSSLContext();

Function for initialization of context is:
    private void initializeSSLContext() throws Exception {
        try {
            sslContext = SSLContext.getInstance("TLSv1");
            System.out.println("Contents with TLSv1 was initiated");
                sslContext.init(null, trustManager, new
java.security.SecureRandom());
            System.out.println("Contents with TLSv1 was initiated with
trustManager");
 
System.out.println(sslContext.getInstance("TLSv1").getProvider());
            if(secure_Mode == 1)
            {
                System.out.println("HostName verification");
                HostnameVerifier hv = new HostnameVerifier() {
                    public boolean verify(String string, SSLSession
ssls)
                    {
                        System.out.println("Warning: URL Host:
"+string + " vs. " + ssls.getPeerHost());
                        return true;
                    }
                };
 
HttpsURLConnection.setDefaultSSLSocketFactory(sslContext.getSocketFactory());
                HttpsURLConnection.setDefaultHostnameVerifier(hv);
            }
            sslSocketFactory = sslContext.getSocketFactory();
            System.out.println("SSL Socket Factory is done");
        }

Initialization of trusted manager is:
    private final void initializeTrustManager() throws Exception {
    // init new TrustManager
        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;
                }
            }
        };
    }

Unfortunatelly when the server certificate is not imported in Trusted
Store then all is working. But this is not good.

best regards
Petr