受下面annser的启发，我找到了一种信任自签名CA并保持信任默认CA的方法。

    File file = new File(System.getProperty("java.home"), "lib/security/cacerts");
    KeyStore keyStore = KeyStore.getInstance(KeyStore.getDefaultType());
    keyStore.load(new FileInputStream(file), "changeit".toCharArray());


    InputStream resourceAsStream = getClass().getClassLoader().getResourceAsStream("testCer.cer");
    Certificate certificate = CertificateFactory.getInstance("X.509").generateCertificate(resourceAsStream);
    keyStore.setCertificateEntry("my-server-alias", certificate);

    TrustManagerFactory trustManagerFactory = TrustManagerFactory.getInstance(TrustManagerFactory.getDefaultAlgorithm());
    trustManagerFactory.init(keyStore);

    SSLContext sslContext = SSLContexts.createDefault();
    sslContext.init(null, trustManagerFactory.getTrustManagers(), null);


    // check domain
    // SSLConnectionSocketFactory socketFactory = new SSLConnectionSocketFactory(sslContext);

    // not check domain
    SSLConnectionSocketFactory socketFactory = new SSLConnectionSocketFactory(sslContext,
            new String[]{"TLSv1","TLSv1.1","TLSv1.2","SSLv3"},null, NoopHostnameVerifier.INSTANCE);

    CloseableHttpClient httpClient = HttpClients.custom().setSSLSocketFactory(socketFactory).build();
    factory.setHttpClient(httpClient);
    RestTemplate restTemplate = new RestTemplate(factory);

使用浏览器从目标页面下载自签名证书，并使用默认密码将其添加到默认存储区:

keytool -import -v -trustcacerts -file selfsigned.crt -alias myserver -keystore /etc/alternatives/jre/lib/security/cacerts -storepass changeit

使用$JAVA_HOME/jre/lib/security/cacerts文件，我这里的例子来自Oracle linux 7.7。

您可以通过在RestTemplate级别禁用它来实现这一点。 注意，此TrustStrategy将信任所有证书，并且使用NoopHostnameVerifier()禁用了主机名验证。

public RestTemplate getRestTemplate() throws KeyStoreException, NoSuchAlgorithmException, KeyManagementException {
    TrustStrategy acceptingTrustStrategy = (x509Certificates, s) -> true;
    SSLContext sslContext = org.apache.http.ssl.SSLContexts.custom().loadTrustMaterial(null, acceptingTrustStrategy).build();
    SSLConnectionSocketFactory csf = new SSLConnectionSocketFactory(sslContext, new NoopHostnameVerifier());
    CloseableHttpClient httpClient = HttpClients.custom().setSSLSocketFactory(csf).build();
    HttpComponentsClientHttpRequestFactory requestFactory = new HttpComponentsClientHttpRequestFactory();
    requestFactory.setHttpClient(httpClient);
    return new RestTemplate(requestFactory);
}       

我有一个问题，我正在传递一个URL到一个库调用URL . openconnection ();我改编了jon-daniel的答案，

public class TrustHostUrlStreamHandler extends URLStreamHandler {

    private static final Logger LOG = LoggerFactory.getLogger(TrustHostUrlStreamHandler.class);

    @Override
    protected URLConnection openConnection(final URL url) throws IOException {

        final URLConnection urlConnection = new URL(url.getProtocol(), url.getHost(), url.getPort(), url.getFile()).openConnection();

        // adapated from
        // https://stackoverflow.com/questions/2893819/accept-servers-self-signed-ssl-certificate-in-java-client
        if (urlConnection instanceof HttpsURLConnection) {
            final HttpsURLConnection conHttps = (HttpsURLConnection) urlConnection;

            try {
                // Set up a Trust all manager
                final TrustManager[] trustAllCerts = new TrustManager[] { new X509TrustManager() {

                    @Override
                    public java.security.cert.X509Certificate[] getAcceptedIssuers() {
                        return null;
                    }

                    @Override
                    public void checkClientTrusted(final java.security.cert.X509Certificate[] certs, final String authType) {
                    }

                    @Override
                    public void checkServerTrusted(final java.security.cert.X509Certificate[] certs, final String authType) {
                    }
                } };

                // Get a new SSL context
                final SSLContext sc = SSLContext.getInstance("TLSv1.2");
                sc.init(null, trustAllCerts, new java.security.SecureRandom());
                // Set our connection to use this SSL context, with the "Trust all" manager in place.
                conHttps.setSSLSocketFactory(sc.getSocketFactory());
                // Also force it to trust all hosts
                final HostnameVerifier allHostsValid = new HostnameVerifier() {
                    @Override
                    public boolean verify(final String hostname, final SSLSession session) {
                        return true;
                    }
                };

                // and set the hostname verifier.
                conHttps.setHostnameVerifier(allHostsValid);

            } catch (final NoSuchAlgorithmException e) {
                LOG.warn("Failed to override URLConnection.", e);
            } catch (final KeyManagementException e) {
                LOG.warn("Failed to override URLConnection.", e);
            }

        } else {
            LOG.warn("Failed to override URLConnection. Incorrect type: {}", urlConnection.getClass().getName());
        }

        return urlConnection;
    }

}

使用这个类可以创建一个新的URL:

trustedUrl = new URL(new URL(originalUrl), "", new TrustHostUrlStreamHandler());
trustedUrl.openConnection();

这样做的好处是它是本地化的，不会替换默认的URL.openConnection。

而不是设置默认的套接字工厂(这在我看来是一件坏事)- yhis只会影响当前连接，而不是你试图打开的每一个SSL连接:

URLConnection connection = url.openConnection();
    // JMD - this is a better way to do it that doesn't override the default SSL factory.
    if (connection instanceof HttpsURLConnection)
    {
        HttpsURLConnection conHttps = (HttpsURLConnection) connection;
        // Set up a Trust all manager
        TrustManager[] trustAllCerts = new TrustManager[] { new X509TrustManager()
        {

            public java.security.cert.X509Certificate[] getAcceptedIssuers()
            {
                return null;
            }

            public void checkClientTrusted(
                java.security.cert.X509Certificate[] certs, String authType)
            {
            }

            public void checkServerTrusted(
                java.security.cert.X509Certificate[] certs, String authType)
            {
            }
        } };

        // Get a new SSL context
        SSLContext sc = SSLContext.getInstance("TLSv1.2");
        sc.init(null, trustAllCerts, new java.security.SecureRandom());
        // Set our connection to use this SSL context, with the "Trust all" manager in place.
        conHttps.setSSLSocketFactory(sc.getSocketFactory());
        // Also force it to trust all hosts
        HostnameVerifier allHostsValid = new HostnameVerifier() {
            public boolean verify(String hostname, SSLSession session) {
                return true;
            }
        };
        // and set the hostname verifier.
        conHttps.setHostnameVerifier(allHostsValid);
    }
InputStream stream = connection.getInputStream();

在RHEL上，您可以从RHEL 6的新版本开始使用update-ca-trust，而不是像上面的注释所建议的那样使用keytool。您需要拥有pem格式的证书。然后

trust anchor <cert.pem>

编辑/etc/pki/ca-trust/source/cert.P11-kit，将“证书类别:other-entry”修改为“证书类别:authority”。(或使用sed在脚本中完成此操作。)然后做

update-ca-trust

几点注意事项:

I couldn't find "trust" on my RHEL 6 server and yum didn't offer to install it. I ended up using it on an RHEL 7 server and copying the .p11-kit file over. To make this work for you, you may need to do update-ca-trust enable. This will replace /etc/pki/java/cacerts with a symbolic link pointing to /etc/pki/ca-trust/extracted/java/cacerts. (So you might want to back up the former first.) If your java client uses cacerts stored in some other location, you'll want to manually replace it with a symlink to /etc/pki/ca-trust/extracted/java/cacerts, or replace it with that file.