我想为smtp.gmail.com导入证书。对我来说唯一有效的办法就是

输入命令查看该证书 D:\openssl\bin\openssl.exe s_client连接smtp.gmail.com:465 将-----BEGIN CERTIFICATE-----和-----END CERTIFICATE-----之间的行复制并保存到一个文件gmail.cer中 运行 keytool -import -alias smtp.gmail.com -keystore "%JAVA_HOME%/jre/lib/security/cacerts" -file C:\Users\Admin\Desktop\gmail.cer 输入密码:changeit 单击“是”，导入证书 重新启动Java

现在运行命令，就可以开始了。

请选择根证书。默认情况下，浏览器选择的子证书可能无法解决问题。有关详细信息，请参阅此线程:无法找到请求目标的有效认证路径

这是一个解决方案，但以我的故事的形式:

我尝试了上面给出的所有解决方案(3天)，几乎要死了，没有一个对我有效。

我失去了所有的希望。

我联系了我的安全团队，因为我在代理服务器后面，他们告诉我他们最近更新了他们的安全策略。

后来他们发布了一个新的“cacerts”文件，其中包含了所有的证书。

我删除了%JAVA_HOME%/jre/lib/security中的cacerts文件，它解决了我的问题。

所以如果你正面临这个问题，它可能来自你的网络团队。

I solved this issue on Windows Server 2016 with Java 8, by importing cert from pkcs12 store to cacerts keystore. Path to pkcs12 store: C:\Apps\pkcs12.pfx Path to Java cacerts: C:\Program Files\Java\jre1.8.0_151\lib\security\cacerts Path to keytool: C:\Program Files\Java\jre1.8.0_151\bin After possitioning to folder with keytool in command prompt (as administrator), command to import cert from pkcs12 to cacerts is as follows: keytool -v -importkeystore -srckeystore C:\Apps\pkcs12.pfx -srcstoretype PKCS12 -destkeystore "C:\Program Files\Java\jre1.8.0_151\lib\security\cacerts" -deststoretype JKS You will be prompted to: 1. enter destination keystore password (cacerts pasword, default is "changeit") 2. enter source keystore password (pkcs12 password)

要使更改生效，请重新启动服务器机器(或只需重新启动JVM)。

-Dmaven.wagon.http.ssl.insecure=true -Dmaven.wagon.http.ssl.allowall=true

用于跳过证书验证。

警告!

仅用于开发目的，这是不安全的!

我偶然发现了这个问题，花了很多时间研究来解决，特别是自动生成的证书，与官方证书不同，它非常棘手，Java不太喜欢它们。

请检查以下链接:用Java解决证书问题

基本上，您必须将服务器上的证书添加到Java Home certs中。

Generate or Get your certificate and configure Tomcat to use it in Servers.xml Download the Java source code of the class InstallCert and execute it while the server is running, providing the following arguments server[:port]. No password is needed, as the original password works for the Java certs ("changeit"). The Program will connect to the server and Java will throw an exception, it will analyze the certificate provided by the server and allow you to create a jssecerts file inside the directory where you executed the Program (If executed from Eclipse then make sure you configure the Work directory in Run -> Configurations). Manually copy that file to $JAVA_HOME/jre/lib/security

遵循这些步骤之后，与证书的连接将不再在Java中生成异常。

下面的源代码很重要，它从(Sun) Oracle博客中消失了，我发现它的唯一页面是在提供的链接上，因此我将它附加在答案中以供参考。

/*
 * Copyright 2006 Sun Microsystems, Inc.  All Rights Reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 *   - Redistributions of source code must retain the above copyright
 *     notice, this list of conditions and the following disclaimer.
 *
 *   - Redistributions in binary form must reproduce the above copyright
 *     notice, this list of conditions and the following disclaimer in the
 *     documentation and/or other materials provided with the distribution.
 *
 *   - Neither the name of Sun Microsystems nor the names of its
 *     contributors may be used to endorse or promote products derived
 *     from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
 * IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
 * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT OWNER OR
 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */
/**
 * Originally from:
 * http://blogs.sun.com/andreas/resource/InstallCert.java
 * Use:
 * java InstallCert hostname
 * Example:
 *% java InstallCert ecc.fedora.redhat.com
 */

import javax.net.ssl.*;
import java.io.*;
import java.security.KeyStore;
import java.security.MessageDigest;
import java.security.cert.CertificateException;
import java.security.cert.X509Certificate;

/**
 * Class used to add the server's certificate to the KeyStore
 * with your trusted certificates.
 */
public class InstallCert {

    public static void main(String[] args) throws Exception {
        String host;
        int port;
        char[] passphrase;
        if ((args.length == 1) || (args.length == 2)) {
            String[] c = args[0].split(":");
            host = c[0];
            port = (c.length == 1) ? 443 : Integer.parseInt(c[1]);
            String p = (args.length == 1) ? "changeit" : args[1];
            passphrase = p.toCharArray();
        } else {
            System.out.println("Usage: java InstallCert [:port] [passphrase]");
            return;
        }

        File file = new File("jssecacerts");
        if (file.isFile() == false) {
            char SEP = File.separatorChar;
            File dir = new File(System.getProperty("java.home") + SEP
                    + "lib" + SEP + "security");
            file = new File(dir, "jssecacerts");
            if (file.isFile() == false) {
                file = new File(dir, "cacerts");
            }
        }
        System.out.println("Loading KeyStore " + file + "...");
        InputStream in = new FileInputStream(file);
        KeyStore ks = KeyStore.getInstance(KeyStore.getDefaultType());
        ks.load(in, passphrase);
        in.close();

        SSLContext context = SSLContext.getInstance("TLS");
        TrustManagerFactory tmf =
                TrustManagerFactory.getInstance(TrustManagerFactory.getDefaultAlgorithm());
        tmf.init(ks);
        X509TrustManager defaultTrustManager = (X509TrustManager) tmf.getTrustManagers()[0];
        SavingTrustManager tm = new SavingTrustManager(defaultTrustManager);
        context.init(null, new TrustManager[]{tm}, null);
        SSLSocketFactory factory = context.getSocketFactory();

        System.out.println("Opening connection to " + host + ":" + port + "...");
        SSLSocket socket = (SSLSocket) factory.createSocket(host, port);
        socket.setSoTimeout(10000);
        try {
            System.out.println("Starting SSL handshake...");
            socket.startHandshake();
            socket.close();
            System.out.println();
            System.out.println("No errors, certificate is already trusted");
        } catch (SSLException e) {
            System.out.println();
            e.printStackTrace(System.out);
        }

        X509Certificate[] chain = tm.chain;
        if (chain == null) {
            System.out.println("Could not obtain server certificate chain");
            return;
        }

        BufferedReader reader =
                new BufferedReader(new InputStreamReader(System.in));

        System.out.println();
        System.out.println("Server sent " + chain.length + " certificate(s):");
        System.out.println();
        MessageDigest sha1 = MessageDigest.getInstance("SHA1");
        MessageDigest md5 = MessageDigest.getInstance("MD5");
        for (int i = 0; i < chain.length; i++) {
            X509Certificate cert = chain[i];
            System.out.println
                    (" " + (i + 1) + " Subject " + cert.getSubjectDN());
            System.out.println("   Issuer  " + cert.getIssuerDN());
            sha1.update(cert.getEncoded());
            System.out.println("   sha1    " + toHexString(sha1.digest()));
            md5.update(cert.getEncoded());
            System.out.println("   md5     " + toHexString(md5.digest()));
            System.out.println();
        }

        System.out.println("Enter certificate to add to trusted keystore or 'q' to quit: [1]");
        String line = reader.readLine().trim();
        int k;
        try {
            k = (line.length() == 0) ? 0 : Integer.parseInt(line) - 1;
        } catch (NumberFormatException e) {
            System.out.println("KeyStore not changed");
            return;
        }

        X509Certificate cert = chain[k];
        String alias = host + "-" + (k + 1);
        ks.setCertificateEntry(alias, cert);

        OutputStream out = new FileOutputStream("jssecacerts");
        ks.store(out, passphrase);
        out.close();

        System.out.println();
        System.out.println(cert);
        System.out.println();
        System.out.println
                ("Added certificate to keystore 'jssecacerts' using alias '"
                        + alias + "'");
    }

    private static final char[] HEXDIGITS = "0123456789abcdef".toCharArray();

    private static String toHexString(byte[] bytes) {
        StringBuilder sb = new StringBuilder(bytes.length * 3);
        for (int b : bytes) {
            b &= 0xff;
            sb.append(HEXDIGITS[b >> 4]);
            sb.append(HEXDIGITS[b & 15]);
            sb.append(' ');
        }
        return sb.toString();
    }

    private static class SavingTrustManager implements X509TrustManager {

        private final X509TrustManager tm;
        private X509Certificate[] chain;

        SavingTrustManager(X509TrustManager tm) {
            this.tm = tm;
        }

        public X509Certificate[] getAcceptedIssuers() {
            throw new UnsupportedOperationException();
        }

        public void checkClientTrusted(X509Certificate[] chain, String authType)
                throws CertificateException {
            throw new UnsupportedOperationException();
        }

        public void checkServerTrusted(X509Certificate[] chain, String authType)
                throws CertificateException {
            this.chain = chain;
            tm.checkServerTrusted(chain, authType);
        }
    }
}