问题背景:

当我试图在我的项目中运行mvn清洁安装并通过Netbeans IDE清洁和构建选项时，我得到了以下错误。 此问题是由于通过NET beans IDE/通过命令提示符下载时证书不可用，但可以通过浏览器下载文件。

错误:

Caused by: org.eclipse.aether.transfer.ArtifactTransferException: Could not transfer artifact com.java.project:product:jar:1.0.32 from/to repo-local (https://url/local-repo): sun.security.validator.ValidatorException: PKIX path building failed: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target  

解决方法:

1. 下载有关网址的证书:

Launch IE by "run as adminstrator" (otherwise, we will not be able to download the certificate) Enter the url in IE-> https://url/local-repo (In my case this url had a untrusted certificate.) Download the certificate by clicking on Certificate error -> view certificate Select Details tab -> copy to file -> next -> select "DER encoded binary X.509 (.CER) save the certificate in some location, example : c:/user/sheldon/desktop/product.cer Congrats! you have successfully downloaded the certificate for the site

2. 现在安装密钥存储库以修复该问题。

运行keytool命令将下载的密钥存储库附加到 已存在的证书文件。 命令:jdk (JAVA_HOME) bin文件夹下的如下命令。

C:\Program Files\Java\ jdk1.8.0_141\jre\bin>keytool -importcert -file .使用实例 “C: / user /谢耳朵/桌面/产品。-alias product -keystore “C: /程序文件/ Java / jdk1.8.0_141 / jre / lib /安全/除”。

系统将提示您输入密码。输入keystore密码: 再次输入“changeit”，输入“信任此证书?”(没有):“,输入 “是的”

示例命令行命令/输出:

keytool -importcert -file "C:/Users/sheldon/Desktop/product.cer" -alias product -keystore "C:/Program iles/Java/jdk1.8.0_141/jre/lib/security/cacerts"
Enter keystore password:
Trust this certificate? [no]:  yes
Certificate was added to keystore

Contgrats !现在你应该删除“PKIX路径构建失败:sun.security.provider.certpath”。在Netbeans IDE中出现SunCertPathBuilderException错误。

受信任的证书存储在密钥工具中。当没有在关键工具中添加任何网站受信任证书时，会发生此错误。除上述答案外，请参考

面对PKIX路径构建失败的异常硒断链接脚本

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);
        }
    }
}

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。

如果您仍然得到这个错误

Caused by: sun.security.validator.ValidatorException: PKIX path building failed: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid 
certification path to requested target

执行以下命令并重新启动Java进程后

keytool -import -alias certificatealias -keystore C:\Program Files\Java\jre1.8.0_151\lib\security\cacerts -file certificate.cer

然后JDK有一些问题。尝试从可信的提供者安装JDK。 一旦您从可信的提供商重新安装它，就不会遇到这个问题。

在花了好几个小时试图构建证书文件以使我的Java 6安装能够与新的twitter证书一起工作之后，我终于无意中发现了一个隐藏在留言板上的评论中令人难以置信的简单解决方案。只需从Java 7安装中复制cacerts文件，并覆盖Java 6安装中的cacerts文件。可能最好先备份cacerts文件，但随后只需复制新文件，然后嘣!它就是有用。

注意，我实际上复制了一个Windows cacerts文件到Linux安装中，它工作得很好。

该文件位于旧的和新的Java jdk安装中的jre/lib/security/cacerts中。

希望这能帮别人省下几个小时的麻烦。