使用Java无法连接HTTPS链接

Question

我想使用Java读取安全URL（HTTPS）。我尝试下面的方法，但它给了我一个错误消息。

public static void main(String[] arg) {
    try {
        URL url = new URL("http://www.google.com");
        System.out.println("Connecting to www.google.com");
        URLConnection ucon = url.openConnection();
        System.out.println("Connectied to www.google.com");
        System.out.println("Retrieving contents from www.google.com");
        String htmlContents = getResponseData(ucon);
        System.out.println("Retrieved contents from Yahoo! as follows");
        System.out.println(htmlContents);
    } catch (Exception e) {
        e.printStackTrace();
    }
}

这使我得到以下输出。

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 com.sun.net.ssl.internal.ssl.Alerts.getSSLException(Alerts.java:150)
    at com.sun.net.ssl.internal.ssl.SSLSocketImpl.fatal(SSLSocketImpl.java:1584)
    at com.sun.net.ssl.internal.ssl.Handshaker.fatalSE(Handshaker.java:174)
    at com.sun.net.ssl.internal.ssl.Handshaker.fatalSE(Handshaker.java:168)
    at com.sun.net.ssl.internal.ssl.ClientHandshaker.serverCertificate(ClientHandshaker.java:848)
    at com.sun.net.ssl.internal.ssl.ClientHandshaker.processMessage(ClientHandshaker.java:106)
    at com.sun.net.ssl.internal.ssl.Handshaker.processLoop(Handshaker.java:495)
    at com.sun.net.ssl.internal.ssl.Handshaker.process_record(Handshaker.java:433)
    at com.sun.net.ssl.internal.ssl.SSLSocketImpl.readRecord(SSLSocketImpl.java:877)
    at com.sun.net.ssl.internal.ssl.SSLSocketImpl.performInitialHandshake(SSLSocketImpl.java:1089)
    at com.sun.net.ssl.internal.ssl.SSLSocketImpl.startHandshake(SSLSocketImpl.java:1116)
    at com.sun.net.ssl.internal.ssl.SSLSocketImpl.startHandshake(SSLSocketImpl.java:1100)
    at sun.net.www.protocol.https.HttpsClient.afterConnect(HttpsClient.java:402)
    at sun.net.www.protocol.https.AbstractDelegateHttpsURLConnection.connect(AbstractDelegateHttpsURLConnection.java:166)
    at sun.net.www.protocol.http.HttpURLConnection.getInputStream(HttpURLConnection.java:960)
    at sun.net.www.protocol.https.HttpsURLConnectionImpl.getInputStream(HttpsURLConnectionImpl.java:234)
    at ReadHtml.getResponseData(ReadHtml.java:24)
    at ReadHtml.main(ReadHtml.java:13)
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:221)
    at sun.security.validator.PKIXValidator.engineValidate(PKIXValidator.java:145)
    at sun.security.validator.Validator.validate(Validator.java:203)
    at com.sun.net.ssl.internal.ssl.X509TrustManagerImpl.checkServerTrusted(X509TrustManagerImpl.java:172)
    at com.sun.net.ssl.internal.ssl.JsseX509TrustManager.checkServerTrusted(SSLContextImpl.java:320)
    at com.sun.net.ssl.internal.ssl.ClientHandshaker.serverCertificate(ClientHandshaker.java:841)
    ... 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:236)
    at java.security.cert.CertPathBuilder.build(CertPathBuilder.java:194)
    at sun.security.validator.PKIXValidator.doBuild(PKIXValidator.java:216)
    ... 18 more

请给我建议，如何解决这个错误。

注意：我将无法获得证书。所以，请不要回答说为了安全而获取证书。

任何形式的指导都将不胜感激。

谢谢。

- Chintanboman

---

你的代码中在哪里使用了https？ - Aubin

@Aubin 可能是在唯一一个他没有为我们提供代码的方法中：getResponseData(ucon);。@Chintanboman 也为我们提供了这个方法的代码。 - BackSlash

@Chintanboman 你需要将证书添加到以下位置： %JAVA_HOME%\lib\security\cacerts。 - SSC

看一下这个。或许会有所帮助。 - Eugene

Answer 1

试试这段代码：

public static void main(String[] arg) throws Exception {
    String url = "https://google.com";

    SSLContext ctx = SSLContext.getInstance("TLS");
    ctx.init(null, new TrustManager[] { new TrustManager() }, null);
    SSLContext.setDefault(ctx);

    HttpsURLConnection conn = (HttpsURLConnection) new URL(url).openConnection();
    conn.setHostnameVerifier(new HostVerifier());
    conn.setRequestMethod("GET");
    conn.connect();
    System.out.println("Response: " + conn.getResponseCode());
}

private static class HostVerifier implements HostnameVerifier {
    @Override
    public boolean verify(String paramString, SSLSession paramSSLSession) {
     return true;
    }
}

private static class TrustManager implements X509TrustManager {

    @Override
    public X509Certificate[] getAcceptedIssuers() {
    return null;
    }

    @Override
    public void checkServerTrusted(X509Certificate[] paramArrayOfX509Certificate, String paramString)
        throws CertificateException {

    }

    @Override
    public void checkClientTrusted(X509Certificate[] paramArrayOfX509Certificate, String paramString)
        throws CertificateException {
    }
}

- Eugene

---

没有必要完全放弃安全性。即使他使用自签名证书，他仍然可以执行适当的密钥管理并正确设置信任存储。 - erickson

Answer 2

似乎问题在于您的信任存储中没有该证书，如果您无法将其添加到信任存储中，请查看此页面。

- Angel Villalain

Answer 3

可以通过配置HostenameVerifier和DefaultSSLSocketFactory关闭运行过程中的验证。

请参见http://www.nakov.com/blog/2009/07/16/disable-certificate-validation-in-java-ssl-connections/。

请注意，这种方法可能会引入安全风险！

- Steve Oh

---

没有必要完全放弃安全性。即使他使用自签名证书，他仍然可以执行适当的密钥管理并正确设置信任存储。 - erickson