Java:unable to find valid certif

Question：unable to find valid certification path to requested target

reason：缺少安全证书

solve：

1.通过以下代码生成证书：

package test.keystore;

import java.io.BufferedReader;

import java.io.File;

import java.io.FileInputStream;

import java.io.FileOutputStream;

import java.io.InputStream;

import java.io.InputStreamReader;

import java.io.OutputStream;

import java.security.KeyStore;

import java.security.MessageDigest;

import java.security.cert.CertificateException;

import java.security.cert.X509Certificate;

import javax.net.ssl.SSLContext;

import javax.net.ssl.SSLException;

import javax.net.ssl.SSLSocket;

import javax.net.ssl.SSLSocketFactory;

import javax.net.ssl.TrustManager;

import javax.net.ssl.TrustManagerFactory;

import javax.net.ssl.X509TrustManager;

/**

 * 安装证书

 *

 * @author   单红宇(365384722)

 * @myblog  http://blog.csdn.net/catoop/

 * @create    2016年4月14日

 */

public class InstallCert {

    // 我们要访问的HTTPS服务，如访问 https://www.shanhy.com

    public static final String hostName = "www.shanhy.com";

    public static void main(String[] args) throws Exception {

        args = new String[]{hostName};

        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);

        }

    }

}

运行以上代码，出现如下报错：

图1

输入1回车，后续便生成证书。eclipse中证书生成是在workspace中的项目目录中，文件名：jssecacerts

2.复制该文件到jdk的security文件中，例如C:\Vendor\jre1.8.0_31\lib\security

图2

3.好了，笑。