mods/scorm_packages/scorm-1.2/java/ATutorApiAdapterApplet.java

   1 /*
   2  * SCORM-1.2 API-Adapter Java Applet for ATutor
   3  * Copyright (c) Matthai Kurian
   4  *
   5  * Made for ATutor, the same license terms as for ATutor itself apply.
   6  *
   7  * This Applet handles communication between ATutor and SCORM-1.2
   8  * Sharable Content Objects (SCOs). Most communication is via Liveconnect.
   9  * CMI (Computer Managed Instruction) data is sent to ATutor through http POST
  10  * to an ATutor server side PHP script. SCORM-1.2 runtime behavior and CMI
  11  * datamodel management is done by the PfPLMS SCORM-1.2 API-Adapter Core.
  12  */
  13
  14 import java.util.Hashtable;
  15 import java.util.Enumeration;
  16 import java.net.*;
  17 import java.io.*;
  18
  19 public  class ATutorApiAdapterApplet
  20         extends java.applet.Applet
  21         implements ch.ethz.pfplms.scorm.api.ApiAdapterInterface
  22 {
  23         private ch.ethz.pfplms.scorm.api.ApiAdapter core;
  24
  25         private Hashtable ATutorScoCmi  = new Hashtable();
  26
  27         private String  ATutorStudentId;
  28         private String  ATutorStudentName;
  29
  30         private String  ATutorScoId;
  31         private String  ATutorPreparedScoId;
  32
  33         private boolean isVerbose   = false;
  34
  35         public ATutorApiAdapterApplet () {
  36                 core = new ch.ethz.pfplms.scorm.api.ApiAdapter ();
  37         }
  38
  39         public  final void init () {
  40                 if (getParameter("verbose") != null) isVerbose = true;
  41                 ATutorStudentId     = getParameter ("student_id");
  42                 ATutorStudentName   = getParameter ("student_name");
  43                 say ("cmi.core.student_id=" +ATutorStudentId);
  44                 say ("cmi.core.student_name=" +ATutorStudentName);
  45         }
  46
  47         private final void say (String s) {
  48                 if (isVerbose) System.out.println (s);
  49         }
  50
  51         private final static String decode (String es) {
  52
  53                 String s = es.replace('+', ' ');
  54                 int l = s.length();
  55
  56                 int a = 0;
  57
  58                 StringBuffer rv = new StringBuffer(l);
  59                 byte[] b = null;
  60
  61                 try {
  62                         int i;
  63                         while ((i = s.indexOf('%', a)) >= 0) {
  64                                 rv.append(s.substring(a, i));
  65                                 a = i;
  66
  67                                 while (i+2 < l && s.charAt(i) == '%') i+=3;
  68
  69                                 if (b == null || b.length < (i-a)/3) {
  70                                         b = new byte[((i-a)/3)];
  71                                 }
  72
  73                                 int x = 0;
  74                                 for (; a < i; a+=3) {
  75                                         b[x++] = (byte) Integer.parseInt(
  76                                                 s.substring(a+1, a+3), 16
  77                                         );
  78                                 }
  79                                 rv.append(new String(b, 0, x, "utf-8"));
  80                         }
  81
  82                         if (a < l) rv.append(s.substring(a));
  83                         return rv.toString();
  84
  85                 } catch (Exception e) {
  86                         return "";
  87                 }
  88         }
  89
  90         /*
  91          * Methods for ATutor to call via Liveconnect
  92          */
  93
  94         public  final void ATutorPrepare (String sco_id) {
  95                 URLConnection po;
  96                 ATutorScoCmi.clear();
  97                 StringBuffer P = new StringBuffer();
  98                 P.append ("&sco_id="+sco_id);
  99                 say ("Retreiving cmi for sco="+sco_id+" from ATutor server");
 100                 try {
 101                         //po = (HttpURLConnection) ( new java.net.URL (
 102                         po = (URLConnection) ( new java.net.URL (
 103                                 getCodeBase().toString() + "read.php"
 104                         )).openConnection();
 105
 106                         po.setRequestProperty (
 107                                 "Content-Type",
 108                                 "application/x-www-form-urlencoded"
 109                         );
 110                         po.setRequestProperty (
 111                                 "Content-Length",
 112                                 Integer.toString (P.length())
 113                         );
 114                         po.setDoOutput (true);
 115                         po.setUseCaches (false);
 116                         //po.setRequestMethod ("POST");
 117                         po.setAllowUserInteraction (false);
 118
 119                         OutputStream os = po.getOutputStream();
 120                         os.write (P.toString().getBytes());
 121                         os.flush ();
 122                         os.close ();
 123
 124                         BufferedReader br = new BufferedReader(
 125                                         new InputStreamReader(
 126                                                 po.getInputStream ()
 127                                         )
 128                         );
 129                         String s, l, r;
 130                         while ((s=br.readLine())!=null) {
 131                                 if (s.indexOf('=') == -1) continue;
 132                                 l = s.substring (0, s.indexOf('='));
 133                                 r = s.substring (s.indexOf('=')+1, s.length());
 134                                 r = decode (r);
 135                                 say (" "+l + "="+r);
 136                                 ATutorScoCmi.put (l,r);
 137                         }
 138                 } catch (Exception e) {
 139                         say ("ATutor cmi retrieval failed.");
 140                         say (e.toString());
 141                 }
 142                 ATutorPreparedScoId = sco_id;
 143                 say ("Done. Note: this was cmi for the next sco ("+sco_id+") to launch.");
 144         }
 145
 146         public  final void ATutorReset (String s) {
 147                 if (s != null && s.equals(ATutorScoId)) {
 148                         ATutorScoId = null;
 149                         core.reset();
 150                         say ("Reset by ATutor client.");
 151                 }
 152         }
 153
 154         private final String ATutorCommit (boolean fin) {
 155
 156                 if (ATutorScoId == null) return "false";
 157
 158                 core.transEnd();
 159                 StringBuffer P = new StringBuffer();
 160                 Hashtable ins = core.getTransNew ();
 161                 Hashtable mod = core.getTransMod ();
 162                 if (fin) {
 163                         Object o = core.sysGet ("cmi.core.entry");
 164                         if (o != null && o.toString().equals ("ab-initio")) {
 165                                 mod.put ("cmi.core.entry", "");
 166                         }
 167                 } else {
 168                         core.transBegin();
 169                 }
 170
 171                 P.append ("&sco_id=" +ATutorScoId);
 172
 173                 int i=0;
 174                 for (Enumeration e = ins.keys(); e.hasMoreElements(); i++) {
 175                         Object l = e.nextElement();
 176                         Object r = ins.get(l);
 177                         P.append("&iL["+i+"]="+l.toString());
 178                         P.append("&iR["+i+"]="+URLEncoder.encode(r.toString()));
 179                 }
 180
 181                 int u=0;
 182                 for (Enumeration e = mod.keys(); e.hasMoreElements(); u++) {
 183                         Object l = e.nextElement();
 184                         Object r = mod.get(l);
 185                         P.append("&uL["+u+"]="+l.toString());
 186                         P.append("&uR["+u+"]="+URLEncoder.encode(r.toString()));
 187                 }
 188
 189                 if (i == 0 && u == 0) {
 190                         say ("Nothing to commit.");
 191                         return "true";
 192                 }
 193
 194                 //HttpURLConnection po;
 195                 URLConnection po;
 196
 197                 try {
 198                         //po = (HttpURLConnection) ( new java.net.URL (
 199                         po = (URLConnection) ( new java.net.URL (
 200                                 getCodeBase().toString()
 201                                 + "write.php"
 202                         )).openConnection();
 203
 204                         po.setRequestProperty (
 205                                 "Content-Type",
 206                                 "application/x-www-form-urlencoded"
 207                         );
 208                         po.setRequestProperty (
 209                                 "Content-Length",
 210                                 Integer.toString (P.length())
 211                         );
 212                         po.setDoOutput (true);
 213                         po.setUseCaches (false);
 214                         //po.setRequestMethod ("POST");
 215                         po.setAllowUserInteraction (false);
 216
 217                         OutputStream os = po.getOutputStream();
 218                         os.write (P.toString().getBytes());
 219                         os.flush ();
 220                         os.close ();
 221
 222                         BufferedReader r = new BufferedReader(
 223                                         new InputStreamReader(
 224                                                 po.getInputStream ()
 225                                         )
 226                         );
 227                         try {
 228                                 String s;
 229                                 while ((s=r.readLine())!=null) {
 230                                         say(s);
 231                                 }
 232                         } catch (EOFException ok) {}
 233                         return "true";
 234
 235                 } catch (Exception e) {
 236                         say ("ATutor cmi storage failed.");
 237                         say (e.toString());
 238                         return "false";
 239                 }
 240         }
 241
 242         public  final String ATutorGetValue (String l) {
 243                 String rv = core.LMSGetValue (l);
 244                 say ("ATutorGetValue("+l+")="+rv);
 245                 return rv;
 246         }
 247
 248         /*
 249          * Liveconnect interface methods for SCO
 250          */
 251
 252         public  final String LMSInitialize (String s) {
 253                 String rv = core.LMSInitialize(s);
 254                 say ("LMSInitialize("+s+")="+rv);
 255                 if (rv.equals("false")) return rv;
 256                 core.reset();
 257                 rv = core.LMSInitialize(s);
 258                 ATutorScoId = ATutorPreparedScoId;
 259                 core.sysPut ("cmi.core.student_id",   ATutorStudentId);
 260                 core.sysPut ("cmi.core.student_name", ATutorStudentName);
 261                 core.sysPut (ATutorScoCmi);
 262                 core.transBegin();
 263                 return rv;
 264         }
 265
 266         public  final String LMSCommit (String s) {
 267                 String rv = core.LMSCommit(s);
 268                 if (rv.equals("false")) return rv;
 269                 rv = ATutorCommit(false);
 270                 say ("LMSCommit("+s+")="+rv);
 271                 return rv;
 272         }
 273
 274         public  final String LMSFinish (String s) {
 275                 String rv = core.LMSFinish(s);
 276                 say ("LMSFinish("+s+")="+rv);
 277                 if (rv.equals("false")) return rv;
 278                 rv = ATutorCommit(true);
 279                 ATutorScoId = null;
 280                 core.reset();
 281                 return rv;
 282         }
 283
 284         public  final String LMSGetDiagnostic (String e) {
 285                 String rv = core.LMSGetDiagnostic (e);
 286                 say ("LMSGetDiagnostic("+e+")="+rv);
 287                 return rv;
 288         }
 289
 290         public  final String LMSGetErrorString (String e) {
 291                 String rv = core.LMSGetErrorString (e);
 292                 say ("LMSGetErrorString("+e+")="+rv);
 293                 return rv;
 294         }
 295
 296         public  final String LMSGetLastError () {
 297                 String rv = core.LMSGetLastError ();
 298                 say ("LMSLastError()="+rv);
 299                 return rv;
 300         }
 301
 302         public  final String LMSGetValue (String l) {
 303                 String rv = core.LMSGetValue (l);
 304                 say ("LMSGetValue("+l+")="+rv);
 305                 return rv;
 306         }
 307
 308         public  final String LMSSetValue (String l, String r) {
 309                 String rv = core.LMSSetValue (l, r);
 310                 say ("LMSSetValue("+l+"="+r+")="+rv);
 311                 return rv;
 312         }
 313 }