java获取https网站证书，附带调用https:webservice接口

一、java 获取https网站证书：

　　1、创建一个java工程，新建InstallCert类，将以下代码复制进去

package com;
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;
 /**
  * 从网站获取java所需的证书，调用时传入域名。
  */
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);
    }
    }  

}  

InstallCert.java

2、eclipse 传入参数（需要获取证书的域名，例：www.baidu.com）运行main方法：

　　

注：这里注意更改参数的类，不要弄错了。

3、点击 run 后控制台会报错，不用管：

在控制台输入 1 回车：

4、完成，会在工程目录下生成证书文件 jssecacerts

==================以上就是获取https网站证书的整个过程。======================

二、 调用https的webservice接口，如果不注册证书的话就会报错。下面是注册证书的步骤：

1、在需要调用webservice接口的类里加一个静态代码块：

    /*
     * 设置证书。
     */
    static{
        javax.net.ssl.HttpsURLConnection.setDefaultHostnameVerifier(
                new javax.net.ssl.HostnameVerifier(){
                    public boolean verify(String hostname,
                            javax.net.ssl.SSLSession sslSession) {
                        //域名或ip地址
                        if (hostname.equals("www.baidu.com")) {
                            return true;
                        }
                        return false;
                    }
                });
        //第二个参数为证书的路径
        System.setProperty("javax.net.ssl.trustStore", "C:\\Program Files\\Java\\jdk1.7.0_45\\jre\\lib\\security\\jssecacerts");
        System.setProperty("javax.net.ssl.trustStorePassword", "changeit");
    }

2、将域名修改为获取证书的域名，这里是 www.baidu.com。

3、设置证书路径，我这里将获取到的证书复制到了jdk的security目录下了。这个目录为jdk的证书存放目录，建议将证书放到此目录。

4、完成，现在可以调用https的webservice接口了。

注：如果经过以上步骤后依然报错，请检查：

1、证书路径是否正确；

2、获取证书时候所填写的域名，是否是要调用的webservice接口的域名；

3、静态代码块里的域名，是否与获取证书的域名对应；