javax.net.ssl.SSLHandshakeException: sun.security.validator.ValidatorException: PKIX path building

在调用一个https站点API的时候出现该错误，而用posman测试时正常。只要逻辑思维正常的人肯定能想到：posman可以，而java httpclient失败，问题肯定httpclient的问题啊。不想听原理、原因的可以直接跳到后面看解决方法，想知其然知其所以然的且容在下BB几句，我用的是jdk 1.8，访问的站点的ssl证书比较新，所以jdk 1.8内不一定有，于是触发了校验异常呗，因为之前调用过微信、支付宝的API也都是https，但是没报这个错，这跟ssl证书有关系，能跟在jdk内内置证书匹配上则能校验通过，反之则校验失败。

知道了原理那就可以八仙过海各显神通了，往海有许多用越过校验的方式跳过，这种有违ssl安全初衷，非常不建议使用，还是用靠谱的、安全的解决方法：下载缺少的证书，并导入使用。

//复制以下代码，然后调用downLoadCertificate方法下载证书

public  static void downLoadCertificate()throws Exception{
    String host;
    int port;
    char[] passphrase;
    String[] h={"wttr.in"};//这是要访问的https站点
    if ((h.length == 1) || (h.length == 2)) {
        String[] c = h[0].split(":");
        host = c[0];
        port = (c.length == 1) ? 443 : Integer.parseInt(c[1]);
        String p = (h.length == 1) ? "changeit" : h[1];
        passphrase = p.toCharArray();
    } else {
        System.out.println("Usage: java InstallCert <host>[: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//下载后保存的路径
                + "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();
    String line = "1";
    System.out.println("you put key is:"+line);
    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);
    }

}

导入证书的方法：

1、将证书copy到$JAVA_HOME/jre/lib/security目录下

2、System.setProperty(“javax.net.ssl.trustStore”, “D:\\jssecacerts”);//替换上你实际的证书位置路径