Java - https帖子提交失败

Question

尝试提交帖子请求但失败了。

  // HTTP POST request
  private final String USER_AGENT = "Mozilla/5.0";
    private void sendPost(String a) throws Exception {

        String url = "https://example.com/ajax/spidcard";
        URL obj = new URL(url);
        HttpsURLConnection con = (HttpsURLConnection) obj.openConnection();

        //add reuqest header
        con.setRequestMethod("POST");
        con.setRequestProperty("User-Agent", USER_AGENT);
        con.setRequestProperty("Accept-Language", "en-US,en;q=0.5");

        //String urlParameters = "sn=C02G8416DRJM&cn=&locale=&caller=&num=12345";
    String urlParameters = "card=" + a;

        // Send post request
        con.setDoOutput(true);
        DataOutputStream wr = new DataOutputStream(con.getOutputStream());
        wr.writeBytes(urlParameters);
        wr.flush();
        wr.close();

        int responseCode = con.getResponseCode();
        System.out.println("\nSending 'POST' request to URL : " + url);
        System.out.println("Post parameters : " + urlParameters);
        System.out.println("Response Code : " + responseCode);

        BufferedReader in = new BufferedReader(
                new InputStreamReader(con.getInputStream()));
        String inputLine;
        StringBuffer response = new StringBuffer();

        while ((inputLine = in.readLine()) != null) {
            response.append(inputLine);
        }
        in.close();

        //print result
        System.out.println(response.toString());

    }

输出：

run:
InformationRetrieval -- ID information:
InformationRetrieval eIDException -- EID Exception: list() failedjavax.smartcardio.CardException: list() failed
Exception in thread "main" 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(Alerts.java:192)
    at sun.security.ssl.SSLSocketImpl.fatal(SSLSocketImpl.java:1904)
    at sun.security.ssl.Handshaker.fatalSE(Handshaker.java:279)
    at sun.security.ssl.Handshaker.fatalSE(Handshaker.java:273)
    at sun.security.ssl.ClientHandshaker.serverCertificate(ClientHandshaker.java:1446)
    at sun.security.ssl.ClientHandshaker.processMessage(ClientHandshaker.java:209)
    at sun.security.ssl.Handshaker.processLoop(Handshaker.java:901)
    at sun.security.ssl.Handshaker.process_record(Handshaker.java:837)
    at sun.security.ssl.SSLSocketImpl.readRecord(SSLSocketImpl.java:1023)
    at sun.security.ssl.SSLSocketImpl.performInitialHandshake(SSLSocketImpl.java:1332)
    at sun.security.ssl.SSLSocketImpl.startHandshake(SSLSocketImpl.java:1359)
    at sun.security.ssl.SSLSocketImpl.startHandshake(SSLSocketImpl.java:1343)
    at sun.net.www.protocol.https.HttpsClient.afterConnect(HttpsClient.java:563)
    at sun.net.www.protocol.https.AbstractDelegateHttpsURLConnection.connect(AbstractDelegateHttpsURLConnection.java:185)
    at sun.net.www.protocol.http.HttpURLConnection.getOutputStream(HttpURLConnection.java:1092)
    at sun.net.www.protocol.https.HttpsURLConnectionImpl.getOutputStream(HttpsURLConnectionImpl.java:250)
    at eid.Eid.sendPost(Eid.java:100)
    at eid.Eid.main(Eid.java:74)
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(PKIXValidator.java:385)
    at sun.security.validator.PKIXValidator.engineValidate(PKIXValidator.java:230)
    at sun.security.validator.Validator.validate(Validator.java:260)
    at sun.security.ssl.X509TrustManagerImpl.validate(X509TrustManagerImpl.java:326)
    at sun.security.ssl.X509TrustManagerImpl.checkTrusted(X509TrustManagerImpl.java:231)
    at sun.security.ssl.X509TrustManagerImpl.checkServerTrusted(X509TrustManagerImpl.java:126)
    at sun.security.ssl.ClientHandshaker.serverCertificate(ClientHandshaker.java:1428)
    ... 13 more
Caused by: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target
    at sun.security.provider.certpath.SunCertPathBuilder.engineBuild(SunCertPathBuilder.java:196)
    at java.security.cert.CertPathBuilder.build(CertPathBuilder.java:268)
    at sun.security.validator.PKIXValidator.doBuild(PKIXValidator.java:380)
    ... 19 more
Java Result: 1
BUILD SUCCESSFUL (total time: 1 second)