有一个更好的替代信任所有证书的方法:创建一个TrustStore，它专门信任给定的证书，并使用它来创建一个SSLContext，从中获取SSLSocketFactory在HttpsURLConnection上进行设置。以下是完整的代码:

File crtFile = new File("server.crt");
Certificate certificate = CertificateFactory.getInstance("X.509").generateCertificate(new FileInputStream(crtFile));
// Or if the crt-file is packaged into a jar file:
// CertificateFactory.getInstance("X.509").generateCertificate(this.class.getClassLoader().getResourceAsStream("server.crt"));


KeyStore keyStore = KeyStore.getInstance(KeyStore.getDefaultType());
keyStore.load(null, null);
keyStore.setCertificateEntry("server", certificate);

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

SSLContext sslContext = SSLContext.getInstance("TLS");
sslContext.init(null, trustManagerFactory.getTrustManagers(), null);

HttpsURLConnection connection = (HttpsURLConnection) new URL(url).openConnection();
connection.setSSLSocketFactory(sslContext.getSocketFactory());

您也可以直接从文件加载KeyStore，或者从任何受信任的来源检索X.509证书。

注意，对于这段代码，将不使用cacerts中的证书。这个特定的HttpsURLConnection将只信任这个特定的证书。

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。

这是第一个有太多答案的古老问题，我认为我可以提供一个更有用的想法:如果服务器所有者拒绝以可信任的方式离线向我提供他们的证书，我会使用这个选项:

从服务器本身检索证书(使用命令行工具而不是浏览器) 将该证书添加到java密钥存储库以信任它。将显示证书的详细信息，以验证它。

# HOSTNAME_PORT is the host that you want to connect to - example: HOSTNAME_PORT=stackoverflow.com:443
HOSTNAME_PORT=hostname_part_of_url_without_https:port

# whatever you want to call the key within the Java key store
MY_KEY_ALIAS=the_key_I_added_with_help_from_stackoverflow

openssl s_client -showcerts -connect $HOSTNAME_PORT </dev/null 2>/dev/null|openssl x509 -outform PEM >mycertfile.pem
sudo keytool -trustcacerts -keystore $JAVA_HOME/jre/lib/security/cacerts/pki/java/cacerts -storepass changeit -importcert -alias $MY_KEY_ALIAS -file mycertfile.pem 

在出现提示时输入yes，但只有在您真正信任显示给您的证书并希望将其添加到计算机的全局java密钥存储库时才可以这样做。

通知你:$ JAVA_HOME / jre / lib /安全/除 在我的情况下(CentOS 7)指向: /etc/pki/java/cacerts

这里基本上有两个选择:将自签名证书添加到JVM信任存储库或将客户端配置为

选项1

从浏览器导出证书，并将其导入JVM信任库(以建立信任链):

<JAVA_HOME>\bin\keytool -import -v -trustcacerts
-alias server-alias -file server.cer
-keystore cacerts.jks -keypass changeit
-storepass changeit 

选项2

禁用证书验证(代码来自Example Depot):

// Create a trust manager that does not validate certificate chains
TrustManager[] trustAllCerts = new TrustManager[] { 
    new X509TrustManager() {     
        public java.security.cert.X509Certificate[] getAcceptedIssuers() { 
            return new X509Certificate[0];
        } 
        public void checkClientTrusted( 
            java.security.cert.X509Certificate[] certs, String authType) {
            } 
        public void checkServerTrusted( 
            java.security.cert.X509Certificate[] certs, String authType) {
        }
    } 
}; 

// Install the all-trusting trust manager
try {
    SSLContext sc = SSLContext.getInstance("SSL"); 
    sc.init(null, trustAllCerts, new java.security.SecureRandom()); 
    HttpsURLConnection.setDefaultSSLSocketFactory(sc.getSocketFactory());
} catch (GeneralSecurityException e) {
} 
// Now you can access an https URL without having the certificate in the truststore
try { 
    URL url = new URL("https://hostname/index.html"); 
} catch (MalformedURLException e) {
} 

请注意，我根本不推荐选项#2。禁用信任管理器会破坏SSL的某些部分，使您容易受到中间人攻击。首选选项#1，或者更好的是，让服务器使用由知名CA签名的“真实”证书。

接受的答案很好，但我想添加一些东西，因为我在Mac上使用IntelliJ，无法使用JAVA_HOME路径变量让它工作。

事实证明，从IntelliJ运行应用程序时，Java Home是不同的。

要找出它的确切位置，只需执行System.getProperty("java.home")，因为可信证书就是从那里读取的。

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.