彻底解决：SunCertPathBuilderException: unable to find valid certification path to requested target错误的方法

请求12306系统查票。之前正常的，现在提示这样的错误：

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

如下图：

 导致原因：由于12306安全系统升级不再支持TLS 1.0,所以。以前jsoup直接可以请求的。现在会被拒绝，

解决方法有4种：

1，直接绕过HTTPS验证 TLS2.0+

    /**
     * 绕过HTTPS验证 TLS2.0+
     */
    static public void initTLS() {
        try {
            SSLContext context = SSLContext.getInstance("TLS");
            context.init(null, new X509TrustManager[]{new X509TrustManager() {
                @Override
                public void checkClientTrusted(X509Certificate[] chain, String authType) {
                }

                @Override
                public void checkServerTrusted(X509Certificate[] chain, String authType) {
                }

                @Override
                public X509Certificate[] getAcceptedIssuers() {
                    return new X509Certificate[0];
                }
            }}, new SecureRandom());
            HttpsURLConnection.setDefaultSSLSocketFactory(context.getSocketFactory());
        } catch (NoSuchAlgorithmException | KeyManagementException ignored) {
        }
    }

调用：在请求代码前执行即可。简单方便高效

initTLS();

2：也是绕过HTTPS验证，跟第一种其实差不多。但是调用方法有区别

    private static SSLSocketFactory socketFactory() {
        TrustManager[] trustAllCerts = new TrustManager[]{new X509TrustManager() {
            public java.security.cert.X509Certificate[] getAcceptedIssuers() {
                return null;
            }
            public void checkClientTrusted(X509Certificate[] certs, String authType) {
            }
            public void checkServerTrusted(X509Certificate[] certs, String authType) {
            }
        }};

        try {
            SSLContext sslContext = SSLContext.getInstance("TLS");
            sslContext.init(null, trustAllCerts, new java.security.SecureRandom());
            return sslContext.getSocketFactory();
        } catch (NoSuchAlgorithmException | KeyManagementException e) {
            throw new RuntimeException("Failed to create a SSL socket factory", e);
        }
    }

调用：在请求代码中执行即可

        Connection.Response response = Jsoup.connect(getTicketListUrl)
                .headers(header)
                .timeout(6000)
                .sslSocketFactory(socketFactory())
                .method(Connection.Method.GET)
                .execute();

注意添加这个：.sslSocketFactory(socketFactory())

3：旧版本的Jsoup有一个参数：据说加上就行了。我现在用的版本没有，估计是取消了

.validateTLSCertificates(false)

4：导入证书：请参考这个连接：

彻底解决unable to find valid certification path to requested target_Gabriel8304的博客-CSDN博客

总结：

第4种：不推荐，为什么？因为我测试了发现还是不行。不知道为什么。而且如果你写爬虫。每一个网站都要操作一次太麻烦了。

运行效果如下图：

 

成功收到返回数据并解析