Java “；PKIX路径生成失败”；和“；找不到请求目标的有效证书路径”；

我在尝试连接服务器url时遇到验证程序异常。 这里我提供了代码。我对这个https连接领域完全陌生。所以，你们谁能帮我解决这个问题。即使在下面，我也提供了异常stacktrace

public class HttpsClient {
static {
    HttpsURLConnection.setDefaultHostnameVerifier(new HostnameVerifier() {
        public boolean verify(String hostname, SSLSession session) {
            return true;
        }
    });
}

public static void main(String[] args) {
    new HttpsClient().testIt();
}

private void testIt() {

    String https_url = "https://127.0.0.1:7854/analysis/216.html";
    URL url;
    try {

        url = new URL(https_url);
        HttpsURLConnection con = (HttpsURLConnection) url.openConnection();

        // dumpl all cert info
        print_https_cert(con);

        // dump all the content
        print_content(con);

    } catch (MalformedURLException e) {
        e.printStackTrace();
    } catch (IOException e) {
        e.printStackTrace();
    }

}

private void print_https_cert(HttpsURLConnection con) {

    if (con != null) {

        try {

            System.out.println("Response Code : " + con.getResponseCode());
            System.out.println("Cipher Suite : " + con.getCipherSuite());
            System.out.println("\n");

            Certificate[] certs = con.getServerCertificates();
            for (Certificate cert : certs) {
                System.out.println("Cert Type : " + cert.getType());
                System.out.println("Cert Hash Code : " + cert.hashCode());
                System.out.println("Cert Public Key Algorithm : " + cert.getPublicKey().getAlgorithm());
                System.out.println("Cert Public Key Format : " + cert.getPublicKey().getFormat());
                System.out.println("\n");
            }

        } catch (SSLPeerUnverifiedException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }

    }

}

private void print_content(HttpsURLConnection con) {
    if (con != null) {

        try {

            System.out.println("****** Content of the URL ********");
            BufferedReader br = new BufferedReader(new InputStreamReader(con.getInputStream()));

            String input;

            while ((input = br.readLine()) != null) {
                System.out.println(input);
            }
            br.close();

        } catch (IOException e) {
            e.printStackTrace();
        }

    }

}

}

通过使用上面的方法，我得到了一个异常，如

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(Unknown Source)
    at sun.security.ssl.SSLSocketImpl.fatal(Unknown Source)
    at sun.security.ssl.Handshaker.fatalSE(Unknown Source)
    at sun.security.ssl.Handshaker.fatalSE(Unknown Source)
    at sun.security.ssl.ClientHandshaker.serverCertificate(Unknown Source)
    at sun.security.ssl.ClientHandshaker.processMessage(Unknown Source)
    at sun.security.ssl.Handshaker.processLoop(Unknown Source)
    at sun.security.ssl.Handshaker.process_record(Unknown Source)
    at sun.security.ssl.SSLSocketImpl.readRecord(Unknown Source)
    at sun.security.ssl.SSLSocketImpl.performInitialHandshake(Unknown Source)
    at sun.security.ssl.SSLSocketImpl.startHandshake(Unknown Source)
    at sun.security.ssl.SSLSocketImpl.startHandshake(Unknown Source)
    at sun.net.www.protocol.https.HttpsClient.afterConnect(Unknown Source)
    at sun.net.www.protocol.https.AbstractDelegateHttpsURLConnection.connect(Unknown Source)
    at sun.net.www.protocol.http.HttpURLConnection.getInputStream0(Unknown Source)
    at sun.net.www.protocol.http.HttpURLConnection.getInputStream(Unknown Source)
    at java.net.HttpURLConnection.getResponseCode(Unknown Source)
    at sun.net.www.protocol.https.HttpsURLConnectionImpl.getResponseCode(Unknown Source)
    at com.embitel.https.test.HttpsClient.print_https_cert(HttpsClient.java:55)
    at com.embitel.https.test.HttpsClient.testIt(HttpsClient.java:36)
    at com.embitel.https.test.HttpsClient.main(HttpsClient.java:23)
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(Unknown Source)
    at sun.security.validator.PKIXValidator.engineValidate(Unknown Source)
    at sun.security.validator.Validator.validate(Unknown Source)
    at sun.security.ssl.X509TrustManagerImpl.validate(Unknown Source)
    at sun.security.ssl.X509TrustManagerImpl.checkTrusted(Unknown Source)
    at sun.security.ssl.X509TrustManagerImpl.checkServerTrusted(Unknown Source)
    ... 17 more
Caused by: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target
    at sun.security.provider.certpath.SunCertPathBuilder.build(Unknown Source)
    at sun.security.provider.certpath.SunCertPathBuilder.engineBuild(Unknown Source)
    at java.security.cert.CertPathBuilder.build(Unknown Source)
    ... 23 more
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.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
    at sun.reflect.NativeConstructorAccessorImpl.newInstance(Unknown Source)
    at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(Unknown Source)
    at java.lang.reflect.Constructor.newInstance(Unknown Source)
    at sun.net.www.protocol.http.HttpURLConnection$10.run(Unknown Source)
    at sun.net.www.protocol.http.HttpURLConnection$10.run(Unknown Source)
    at java.security.AccessController.doPrivileged(Native Method)
    at sun.net.www.protocol.http.HttpURLConnection.getChainedException(Unknown Source)
    at sun.net.www.protocol.http.HttpURLConnection.getInputStream0(Unknown Source)
    at sun.net.www.protocol.http.HttpURLConnection.getInputStream(Unknown Source)
    at sun.net.www.protocol.https.HttpsURLConnectionImpl.getInputStream(Unknown Source)
    at com.embitel.https.test.HttpsClient.print_content(HttpsClient.java:84)
    at com.embitel.https.test.HttpsClient.testIt(HttpsClient.java:39)
    at com.embitel.https.test.HttpsClient.main(HttpsClient.java:23)
Caused by: 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(Unknown Source)
    at sun.security.ssl.SSLSocketImpl.fatal(Unknown Source)
    at sun.security.ssl.Handshaker.fatalSE(Unknown Source)
    at sun.security.ssl.Handshaker.fatalSE(Unknown Source)
    at sun.security.ssl.ClientHandshaker.serverCertificate(Unknown Source)
    at sun.security.ssl.ClientHandshaker.processMessage(Unknown Source)
    at sun.security.ssl.Handshaker.processLoop(Unknown Source)
    at sun.security.ssl.Handshaker.process_record(Unknown Source)
    at sun.security.ssl.SSLSocketImpl.readRecord(Unknown Source)
    at sun.security.ssl.SSLSocketImpl.performInitialHandshake(Unknown Source)
    at sun.security.ssl.SSLSocketImpl.startHandshake(Unknown Source)
    at sun.security.ssl.SSLSocketImpl.startHandshake(Unknown Source)
    at sun.net.www.protocol.https.HttpsClient.afterConnect(Unknown Source)
    at sun.net.www.protocol.https.AbstractDelegateHttpsURLConnection.connect(Unknown Source)
    at sun.net.www.protocol.http.HttpURLConnection.getInputStream0(Unknown Source)
    at sun.net.www.protocol.http.HttpURLConnection.getInputStream(Unknown Source)
    at java.net.HttpURLConnection.getResponseCode(Unknown Source)
    at sun.net.www.protocol.https.HttpsURLConnectionImpl.getResponseCode(Unknown Source)
    at com.embitel.https.test.HttpsClient.print_https_cert(HttpsClient.java:55)
    at com.embitel.https.test.HttpsClient.testIt(HttpsClient.java:36)
    ... 1 more
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(Unknown Source)
    at sun.security.validator.PKIXValidator.engineValidate(Unknown Source)
    at sun.security.validator.Validator.validate(Unknown Source)
    at sun.security.ssl.X509TrustManagerImpl.validate(Unknown Source)
    at sun.security.ssl.X509TrustManagerImpl.checkTrusted(Unknown Source)
    at sun.security.ssl.X509TrustManagerImpl.checkServerTrusted(Unknown Source)
    ... 17 more
****** Content of the URL ********
Caused by: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target
    at sun.security.provider.certpath.SunCertPathBuilder.build(Unknown Source)
    at sun.security.provider.certpath.SunCertPathBuilder.engineBuild(Unknown Source)
    at java.security.cert.CertPathBuilder.build(Unknown Source)
    ... 23 more

可能重复的