[网络协议]解决Exception in thread “main“ javax.net.ssl.SSLHandshakeException: PKIX path building failed: sun.sec

访问一个接口，通过postman可以调用但是使用HttpClient无法访问报错误。
Exception in thread “main” javax.net.ssl.SSLHandshakeException: PKIX path building failed: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target
at sun.security.ssl.Alert.createSSLException(Alert.java:131)
at sun.security.ssl.TransportContext.fatal(TransportContext.java:327)
at sun.security.ssl.TransportContext.fatal(TransportContext.java:270)
at sun.security.ssl.TransportContext.fatal(TransportContext.java:265)
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:439)
at sun.security.validator.PKIXValidator.engineValidate(PKIXValidator.java:306)
at sun.security.validator.Validator.validate(Validator.java:271)
HTTP 协议可能是现在 Internet 上使用得最多、最重要的协议了，越来越多的 Java 应用程序需要直接通过 HTTP 协议来访问网络资源。虽然在 JDK 的 java.net 包中已经提供了访问 HTTP 协议的基本功能，但是对于大部分应用程序来说，JDK 库本身提供的功能还不够丰富和灵活。HttpClient 是 Apache Jakarta Common 下的子项目，用来提供高效的、最新的、功能丰富的支持 HTTP 协议的客户端编程工具包，并且它支持 HTTP 协议最新的版本和建议。
解决方式是

private static CloseableHttpClient client = null;
static {
    SSLContext sslcontext = null;
    try {
        sslcontext = createIgnoreVerifySSL();
    } catch (Exception e) {
        e.printStackTrace();
    }
    Registry<ConnectionSocketFactory> socketFactoryRegistry = RegistryBuilder.<ConnectionSocketFactory>create()
            .register("http", PlainConnectionSocketFactory.INSTANCE)
            .register("https", new SSLConnectionSocketFactory(sslcontext))
            .build();
    PoolingHttpClientConnectionManager connManager = new PoolingHttpClientConnectionManager(socketFactoryRegistry);
    HttpClients.custom().setConnectionManager(connManager);
    client = HttpClients.custom().setConnectionManager(connManager).build();
}
public static SSLContext createIgnoreVerifySSL() throws NoSuchAlgorithmException, KeyManagementException {
    SSLContext sc = SSLContext.getInstance("SSLv3");

    // 实现一个X509TrustManager接口，用于绕过验证，不用修改里面的方法
    X509TrustManager trustManager = new X509TrustManager() {
        @Override
        public void checkClientTrusted(
                java.security.cert.X509Certificate[] paramArrayOfX509Certificate,
                String paramString) throws CertificateException {
        }

        @Override
        public void checkServerTrusted(
                java.security.cert.X509Certificate[] paramArrayOfX509Certificate,
                String paramString) throws CertificateException {
        }

        @Override
        public java.security.cert.X509Certificate[] getAcceptedIssuers() {
            return null;
        }
    };
    sc.init(null, new TrustManager[]{trustManager}, null);
    return sc;
}

这样会绕过SSL，https证书。