unable to find valid certification path to requested target
[WARNING] Could not transfer metadata org.sonarsource.sonar-packaging-maven-plugin:sonar-packaging-maven-plugin/maven-metadata.xml from/to central (https://repo.maven.apache.org/maven2): sun.security.validator.ValidatorException: PKIX path building failed: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target
使用技术：maven 仓库：阿里云
如果报上边那个错误，有多种情况，最直接的方法就是换仓库，可以换国内的或国外的，
国内的下载快，但第三方可能存在验证问题；国外的下载较慢，其实也不是很慢，推荐国外使用maven官方的。
首先说一下我最后的解决方法。
我的方法一：
打开idea---》setting---》runnner
在vm options中添加：-Dmaven.wagon.http.ssl.insecure=true -Dmaven.wagon.http.ssl.allowall=true 中间用空格隔开
根据网上搜查，大致还有以下几个方案，不过我尝试都没效果
1.删除本地仓库依赖（我删除了本地仓库，没有效果，反而使项目依赖全都没有，一堆爆红）
2.判斷是连到 repo.maven.apache.org 的时候凭证未信任.
1 /* 2 * Copyright 2006 Sun Microsystems, Inc. All Rights Reserved. 3 * 4 * Redistribution and use in source and binary forms, with or without 5 * modification, are permitted provided that the following conditions 6 * are met: 7 * 8 * - Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 11 * - Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 15 * - Neither the name of Sun Microsystems nor the names of its 16 * contributors may be used to endorse or promote products derived 17 * from this software without specific prior written permission. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS 20 * IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, 21 * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 22 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR 23 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, 24 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, 25 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR 26 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF 27 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING 28 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS 29 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 30 */ 31 /** 32 * Originally from: 33 * http://blogs.sun.com/andreas/resource/InstallCert.java 34 * Use: 35 * java InstallCert hostname 36 * Example: 37 *% java InstallCert ecc.fedora.redhat.com 38 */ 39 40 import javax.net.ssl.*; 41 import java.io.*; 42 import java.net.Socket; 43 44 import java.security.KeyStore; 45 import java.security.MessageDigest; 46 import java.security.cert.CertificateException; 47 import java.security.cert.X509Certificate; 48 49 /** 50 * Class used to add the server's certificate to the KeyStore 51 * with your trusted certificates. 52 */ 53 public class InstallCert { 54 55 public static void main(String[] args) throws Exception { 56 String host; 57 int port; 58 char[] passphrase; 59 if ((args.length == 1) || (args.length == 2)) { 60 String[] c = args[0].split(":"); 61 host = c[0]; 62 port = (c.length == 1) ? 443 : Integer.parseInt(c[1]); 63 String p = (args.length == 1) ? "changeit" : args[1]; 64 passphrase = p.toCharArray(); 65 } else { 66 System.out.println("Usage: java InstallCert <host>[:port] [passphrase]"); 67 return; 68 } 69 70 File file = new File("jssecacerts"); 71 if (file.isFile() == false) { 72 char SEP = File.separatorChar; 73 File dir = new File(System.getProperty("java.home") + SEP 74 + "lib" + SEP + "security"); 75 file = new File(dir, "jssecacerts"); 76 if (file.isFile() == false) { 77 file = new File(dir, "cacerts"); 78 } 79 } 80 System.out.println("Loading KeyStore " + file + "..."); 81 InputStream in = new FileInputStream(file); 82 KeyStore ks = KeyStore.getInstance(KeyStore.getDefaultType()); 83 ks.load(in, passphrase); 84 in.close(); 85 86 SSLContext context = SSLContext.getInstance("TLS"); 87 TrustManagerFactory tmf = 88 TrustManagerFactory.getInstance(TrustManagerFactory.getDefaultAlgorithm()); 89 tmf.init(ks); 90 X509TrustManager defaultTrustManager = (X509TrustManager) tmf.getTrustManagers()[0]; 91 SavingTrustManager tm = new SavingTrustManager(defaultTrustManager); 92 context.init(null, new TrustManager[]{tm}, null); 93 SSLSocketFactory factory = context.getSocketFactory(); 94 95 System.out.println("Opening connection to " + host + ":" + port + "..."); 96 SSLSocket socket = (SSLSocket) factory.createSocket(host, port); 97 socket.setSoTimeout(10000); 98 try { 99 System.out.println("Starting SSL handshake..."); 100 socket.startHandshake(); 101 socket.close(); 102 System.out.println(); 103 System.out.println("No errors, certificate is already trusted"); 104 } catch (SSLException e) { 105 System.out.println(); 106 e.printStackTrace(System.out); 107 } 108 109 X509Certificate[] chain = tm.chain; 110 if (chain == null) { 111 System.out.println("Could not obtain server certificate chain"); 112 return; 113 } 114 115 BufferedReader reader = 116 new BufferedReader(new InputStreamReader(System.in)); 117 118 System.out.println(); 119 System.out.println("Server sent " + chain.length + " certificate(s):"); 120 System.out.println(); 121 MessageDigest sha1 = MessageDigest.getInstance("SHA1"); 122 MessageDigest md5 = MessageDigest.getInstance("MD5"); 123 for (int i = 0; i < chain.length; i++) { 124 X509Certificate cert = chain[i]; 125 System.out.println 126 (" " + (i + 1) + " Subject " + cert.getSubjectDN()); 127 System.out.println(" Issuer " + cert.getIssuerDN()); 128 sha1.update(cert.getEncoded()); 129 System.out.println(" sha1 " + toHexString(sha1.digest())); 130 md5.update(cert.getEncoded()); 131 System.out.println(" md5 " + toHexString(md5.digest())); 132 System.out.println(); 133 } 134 135 System.out.println("Enter certificate to add to trusted keystore or 'q' to quit: [1]"); 136 String line = reader.readLine().trim(); 137 int k; 138 try { 139 k = (line.length() == 0) ? 0 : Integer.parseInt(line) - 1; 140 } catch (NumberFormatException e) { 141 System.out.println("KeyStore not changed"); 142 return; 143 } 144 145 X509Certificate cert = chain[k]; 146 String alias = host + "-" + (k + 1); 147 ks.setCertificateEntry(alias, cert); 148 149 OutputStream out = new FileOutputStream("jssecacerts"); 150 ks.store(out, passphrase); 151 out.close(); 152 153 System.out.println(); 154 System.out.println(cert); 155 System.out.println(); 156 System.out.println 157 ("Added certificate to keystore 'jssecacerts' using alias '" 158 + alias + "'"); 159 } 160 161 private static final char[] HEXDIGITS = "0123456789abcdef".toCharArray(); 162 163 private static String toHexString(byte[] bytes) { 164 StringBuilder sb = new StringBuilder(bytes.length * 3); 165 for (int b : bytes) { 166 b &= 0xff; 167 sb.append(HEXDIGITS[b >> 4]); 168 sb.append(HEXDIGITS[b & 15]); 169 sb.append(' '); 170 } 171 return sb.toString(); 172 } 173 174 private static class SavingTrustManager implements X509TrustManager { 175 176 private final X509TrustManager tm; 177 private X509Certificate[] chain; 178 179 SavingTrustManager(X509TrustManager tm) { 180 this.tm = tm; 181 } 182 183 public X509Certificate[] getAcceptedIssuers() { 184 185 /** 186 * This change has been done due to the following resolution advised for Java 1.7+ 187 http://infposs.blogspot.kr/2013/06/installcert-and-java-7.html 188 **/ 189 190 return new X509Certificate[0]; 191 //throw new UnsupportedOperationException(); 192 } 193 194 public void checkClientTrusted(X509Certificate[] chain, String authType) 195 throws CertificateException { 196 throw new UnsupportedOperationException(); 197 } 198 199 public void checkServerTrusted(X509Certificate[] chain, String authType) 200 throws CertificateException { 201 this.chain = chain; 202 tm.checkServerTrusted(chain, authType); 203 } 204 } 205 }
打包
$ javac InstallCert.java
執行
$ java InstallCert repo.maven.apache.org
他會問你
Enter certificate to add to trusted keystore or 'q' to quit: [1]
輸入 1 ,之後會在執行目錄下生成 jssecacerts
將“jssecacerts”的文件放入JAVA_HOME/jre/lib/security目錄下
再進行maven編譯就可以了
