HTTPS中SunCertPathBuilderException: unable to find valid certification path to requested target

在配置测试环境的时候报告unable to find valid certification path to requested target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
    at sun.security.validator.PKIXValidator.doBuild(PKIXValidator.java:323)
    at sun.security.validator.PKIXValidator.engineValidate(PKIXValidator.java:217)
    at sun.security.validator.Validator.validate(Validator.java:218)
    at com.sun.net.ssl.internal.ssl.X509TrustManagerImpl.validate(X509TrustManagerImpl.java:126)
    at com.sun.net.ssl.internal.ssl.X509TrustManagerImpl.checkServerTrusted(X509TrustManagerImpl.java:209)
    at com.sun.net.ssl.internal.ssl.X509TrustManagerImpl.checkServerTrusted(X509TrustManagerImpl.java:249)
    at com.sun.net.ssl.internal.ssl.ClientHandshaker.serverCertificate(ClientHandshaker.java:1185)
    ... 47 more

网上一搜，找到了解决办法。

当java客户端请求实现https协议的服务时，出现异常：'unable to find valid certification path to requested target'

是因为服务期端的证书没有被认证，需要做的是把服务端证书导入到java keystore。可以附件中的java类实现。

使用方法： java InstallCert <host>[:port] [passphrase]      

这个java类会打开一个连接到你指定的host，开始握手过程。如果出现异常会打印到控制台并且会显示服务端所使用的证书，此时它会问你是否要把证书加入到你的keystore。

如果你不想加，输入"q",否则输入"1".

当你输入"1"后，InstallCert.java 会显示证书的有关信息，然后把证书导入到一个名为"jssecacerts"的keystore中(当前目录），只需要把这个文件拷贝到 JAVA_HOME/jre/lib/security目录中，重命名为"cacerts".

我按照这个过程做了，但是黑体部分刚开始没注意，还是报错。重新执行了一遍才好了。

代码：

/* * 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. */import java.io.*;import java.net.URL;import java.security.*;import java.security.cert.*;import javax.net.ssl.*;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 <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    + "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);}    }}