Tomcat应用访问SSL或https失败的解决办法

一，首先，解决unable to find valid certification path to requested target的问题。

其实就是要生成证书， 让tomcat读取证书

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;
 
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);
        }
    }
 
}  

　　在把证书放到$JAVA_HOME/jre/lib/security目录下

要么就是在浏览器里面打开网站的证书， 导出来上传到服务器上， 然后导入到tomcat默认的cacerts

二，然后， 如果问题未解决出现“Certificate doesn't match any of the subject alternative names”

这时候， 需要改造代码

a. 方案1：使用HttpURLConnection 请求https地址， 例子如下：

import java.net.HttpURLConnection;

public static HttpURLConnection connectToWeb(String uri) {
    HttpURLConnection connection = null;
    try {
        URL url = new URL(uri);
        connection = (HttpURLConnection) url.openConnection();
        connection.setRequestMethod("GET");
        connection.connect();
    } catch (MalformedURLException ex) {
        ex.printStackTrace();
    } catch (IOException ex) {
        ex.printStackTrace();
    }
    return connection;
}

b.方案2：使用SSLConnectionSocketFactory，例子如下：

public static CloseableHttpClient createSSLClientDefault() {
        CloseableHttpClient client = null;
        try {
            SSLContext sslContext = null;
            sslContext = new SSLContextBuilder().loadTrustMaterial(null, new TrustStrategy() {
                @Override
                public boolean isTrusted(X509Certificate[] chain, String authType) throws CertificateException {
                    return true;
                }
            }).build();
            SSLConnectionSocketFactory sslsf = new SSLConnectionSocketFactory(sslContext, NoopHostnameVerifier.INSTANCE);//这里的红色部分
            client = HttpClients.custom().setSSLSocketFactory(sslsf).build();
        } catch (NoSuchAlgorithmException | KeyStoreException | KeyManagementException e) {
            e.printStackTrace();
        }
        return client;
    }