Java get HTTPS Web site certificate

ImportJava.io.BufferedReader;ImportJava.io.File;ImportJava.io.FileInputStream;ImportJava.io.FileOutputStream;ImportJava.io.InputStream;ImportJava.io.InputStreamReader;ImportJava.io.OutputStream;ImportJava.security.KeyStore;Importjava.security.MessageDigest;Importjava.security.cert.CertificateException;Importjava.security.cert.X509Certificate;ImportJavax.net.ssl.SSLContext;Importjavax.net.ssl.SSLException;ImportJavax.net.ssl.SSLSocket;Importjavax.net.ssl.SSLSocketFactory;ImportJavax.net.ssl.TrustManager;Importjavax.net.ssl.TrustManagerFactory;ImportJavax.net.ssl.X509TrustManager; /*** Obtain the required Java certificate from the website, and pass in the domain name when calling. */ Public classZS { Public Static voidMain (string[] args)throwsException {String host; intPort; 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 ); return; } File File=NewFile ("Jssecacerts"); if(File.isfile () = =false) {          CharSEP =File.separatorchar; File dir=NewFile (System.getproperty ("java.home") +SEP+ "Lib" + SEP + "security"); File=NewFile (dir, "Jssecacerts"); if(File.isfile () = =false) {file=NewFile (dir, "Cacerts"); }} System.out.println ("Loading KeyStore" + file + "..."); InputStream in=Newfileinputstream (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=NewSavingtrustmanager (Defaulttrustmanager); Context.init (NULL,NewTrustmanager[] {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=NewBufferedReader (NewInputStreamReader (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(inti = 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 (); intK; 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=NewFileOutputStream ("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 StaticString tohexstring (byte[] bytes) {StringBuilder SB=NewStringBuilder (Bytes.length * 3);  for(intb:bytes) {b&= 0xFF; Sb.append (Hexdigits[b>> 4]); Sb.append (Hexdigits[b& 15]); Sb.append (‘ ‘); }      returnsb.tostring (); }        Private Static classSavingtrustmanagerImplementsX509trustmanager {Private FinalX509trustmanager TM; Privatex509certificate[] chain; Savingtrustmanager (X509trustmanager tm) { This. TM =TM; }         Publicx509certificate[] Getacceptedissuers () {Throw Newunsupportedoperationexception (); }         Public voidcheckclienttrusted (x509certificate[] chain, String authtype)throwscertificateexception {Throw Newunsupportedoperationexception (); }         Public voidcheckservertrusted (x509certificate[] chain, String authtype)throwscertificateexception { This. Chain =chain;      Tm.checkservertrusted (chain, authtype); }      }    }  

Java get HTTPS Web site certificate