The R Project SVN – R – Diff – /trunk/doc/html/search/SearchEngine.java


/*==============================================================================
 
  Project: Simple JAVA Search Engine for Keyword Search
  
  JAVA Source file for the class SearchEngine
  
  COPYRIGHT (C), 1998, Thomas Baier
 
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2 of the License, or
 *  (at your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program; if not, write to the Free Software
 *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 
  $Source: /scratch/CVS-ARCHIVE/R/doc/html/search/SearchEngine.java,v $
  
  $Revision: 1.3 $
 
  $Date: 1999/08/10 09:56:03 $
  
  $Author: ripley $
 
==============================================================================*/
 
 
/* -------------------------------- Imports --------------------------------- */
 
import java.applet.*;
import java.awt.*;
import java.net.*;
import java.io.*;
import java.util.*;
 
 
/*==============================================================================
                          Interface of class SearchEngine
==============================================================================*/
 
/*------------------------------------------------------------------------------
  CLASS:    SearchEngine
  SUPER:    Applet
  CONF. TO: 
  PURPOSE:  
  NOTES:    
 
  HISTORY:  98-04-26: created 
            98-05-15: new member for search mode
------------------------------------------------------------------------------*/
public class SearchEngine extends Applet
{
  /*============================================================================
                                Public methods
  ============================================================================*/
 
  /*----------------------------------------------------------------------------
    INTERFACE: 
    PURPOSE:   default constructor
  	      
    NOTES:     
  
    PARAMS:    
    THROWS:    
    RETURNS:   void
  
    HISTORY:   98-04-26: created
               98-05-03: now reads the index file
	       98-05-15: init new member
  ----------------------------------------------------------------------------*/
  public SearchEngine ()
  {
    iIndexTable = null;
    iSearchTerm = null;
    iSearchMode = 0;
 
    Tracer.write ("SearchEngine initializing\n");
 
    return;
  }
 
 
  /*----------------------------------------------------------------------------
    INTERFACE: 
    PURPOSE:   return general information about the applet
  	       
    NOTES:     
  
    PARAMS:    
    THROWS:    
    RETURNS:   String: the information
  
    HISTORY:   98-04-26: created
  ----------------------------------------------------------------------------*/
  public String getAppletInfo ()
  {
    return "Name: SearchEngine\r\n" +
      "Author: Thomas Baier\r\n" +
      "(C) 1998 Thomas Baier, ALL RIGHTS RESERVED";
  }
 
 
  /*----------------------------------------------------------------------------
    INTERFACE: 
    PURPOSE:   perform initialization
  	      
    NOTES:     creates the controls
  
    PARAMS:    
    THROWS:    
    RETURNS:   void
  
    HISTORY:   98-04-26: created
               98-05-03: now a do-nothing
  ----------------------------------------------------------------------------*/
  public void init ()
  {
    resize(640, 240);
 
    // get the name of the index file
    String indexName = getParameter (cIndexKeyword);
    String searchTerm = getParameter (cSearchKeyword);
 
    Tracer.write ("Index file is \"" + indexName + "\"\n");
    Tracer.write ("Search term is \"" + searchTerm + "\"\n");
 
    // use a default index file if none specified
    if (indexName == null) {
      indexName = cIndexFile;
    }
 
    iSearchTerm = searchTerm;
 
    /*
     * examine the URL to get the search term...
     *
     * if the URL ends with ?SEARCHTERM=xxxxx we know, xxxxx is the search term
     */
    {
      URL url = getDocumentBase ();
      String urlString = url.toString ();
      int index = urlString.indexOf ("?" + cSearchKeyword + "=");
 
      Tracer.write ("URL is \"" + urlString + "\"\n");
 
      // if found, take the rest as the search string
      if (index >= 0) {
	iSearchTerm =
	  urlString.substring (index + 2 + cSearchKeyword.length ());
	Tracer.write ("found search term \"" + iSearchTerm + "\" in URL\n");
      }
    }
 
    readIndexFile (indexName);
 
    return;
  }
 
 
  /*----------------------------------------------------------------------------
    INTERFACE: 
    PURPOSE:   perform "destructor" code
  	      
    NOTES:     not required here
  
    PARAMS:    
    THROWS:    
    RETURNS:   void
  
    HISTORY:   98-04-26: created
  ----------------------------------------------------------------------------*/
  public void destroy ()
  {
    return;
  }
 
 
  /*----------------------------------------------------------------------------
    INTERFACE: 
    PURPOSE:   perform painting of the applet
  	      
    NOTES:     not required for our applet, controls do everything
  
    PARAMS:    Graphics g: the graphics context to draw on
    THROWS:    
    RETURNS:   void
  
    HISTORY:   98-04-26: created
  ----------------------------------------------------------------------------*/
  public void paint (Graphics g)
  {
  
    return;
  }
 
 
  /*----------------------------------------------------------------------------
    INTERFACE: 
    PURPOSE:   perform startup code everytime visiting the applet
  	      
    NOTES:     
  
    PARAMS:    
    THROWS:    
    RETURNS:   void
  
    HISTORY:   98-04-26: created
               98-05-10: start the tracer
  ----------------------------------------------------------------------------*/
  public void start ()
  {
    Tracer.start ();
    return;
  }
 
 
  /*----------------------------------------------------------------------------
    INTERFACE: 
    PURPOSE:   perform cleanup evertime the applet "loses" the focus
  	      
    NOTES:     
  
    PARAMS:    
    THROWS:    
    RETURNS:   void
  
    HISTORY:   98-04-26: created
               98-05-10: stop the tracer
  ----------------------------------------------------------------------------*/
  public void stop ()
  {
    Tracer.stop ();
    return;
  }
 
 
  /*----------------------------------------------------------------------------
    INTERFACE: 
    PURPOSE:   perform the search and return the search results as a string
  	      
    NOTES:     
  
    PARAMS:    
    THROWS:    
    RETURNS:   void
  
    HISTORY:   98-05-03: created
               98-05-08: new format for output
	       98-05-09: added trace
	       98-05-10: now a front-end for search()
	       98-05-15: new parameter for search-mode
  ----------------------------------------------------------------------------*/
  public String search (String key,boolean searchTitles)
  {
    iSearchTerm = key;
 
    if (searchTitles) {
      iSearchMode = IndexTable.cSearchDescription;
    } else {
      iSearchMode = 0;
    }
 
    return internalSearch ();
  }
 
 
  /*----------------------------------------------------------------------------
    INTERFACE: 
    PURPOSE:   perform the search (back-end)
  	      
    NOTES:     
  
    PARAMS:    
    THROWS:    
    RETURNS:   void
  
    HISTORY:   98-05-10: created
               98-05-15: forward search-mode
  ----------------------------------------------------------------------------*/
  public String internalSearch ()
  {
    Tracer.write ("Search for \"" + iSearchTerm + "\" started");
 
    Vector foundItems = null;
 
    if (iSearchTerm != null) {
      foundItems = iIndexTable.search (iSearchTerm,iSearchMode);
    } else {
      foundItems = null;
    }
 
    String result = null;
 
    // if nothing found, return a special string
    if (foundItems == null) {
      result = "No matches for <b>\"" + 
	iSearchTerm +
	"\"</b> have been found!<hr>";
    } else {
      Enumeration cursor = foundItems.elements ();
 
      result =
	"The search string was <b>\"" +
	iSearchTerm +
	"</b>\"" +
	"<hr>" +
	"<dl>";
 
      while (cursor.hasMoreElements ()) {
	IndexEntry entry = (IndexEntry) cursor.nextElement ();
 
	/*
	 * the format for every entry is
	 *
	 * title
	 *   description
	 */
 
	result +=
	  "<dt><a href=\"" +
	  entry.getURL () +
	  "\">" +
	  entry.getTitle () +
	  "</a></dt>\n";
	result += "<dd>" + entry.getDescription () + "</dd>\n";
      }
 
      result += "</dl>";
    }
 
    return result;
  }
 
 
  /*============================================================================
                              Protected methods
  ============================================================================*/
 
  /*============================================================================
                               Private methods
  ============================================================================*/
 
  /*----------------------------------------------------------------------------
    INTERFACE: 
    PURPOSE:   read the index file
  	      
    NOTES:     
  
    PARAMS:    
    THROWS:    
    RETURNS:   void
  
    HISTORY:   98-04-26: created
               98-05-08: now use an IndexStream
	       98-05-10: also use prefix and suffix, build URL from first key
	       98-05-19: add "Alias:" entry to keywords
	       98-06-01: bugfix: don't null the variables
  ----------------------------------------------------------------------------*/
  private void readIndexFile (String idxFile)
  {
    // create the index table
    iIndexTable = new IndexTable ();
 
    URL baseURL = getCodeBase ();
 
    // get the index file and parse its contents
    try {
      URL idxFileURL = new URL (baseURL,idxFile);
 
      // get an IndexStream object for ease of parsing
      IndexStream idxStream = new IndexStream (idxFileURL);
 
      // now start parsing...
      
      /*
       * An entry consists of a title, keywords, an URL and a description.
       * everything else is ignored. Every entry starts with the keyword
       * "Entry" (case is ignored)
       *
       * must-have entries are "Entry" and "Keywords"
       *
       * 98-06-01: bugfix: don't null the variables
       */
      String entry = "";
      String keywords = "";
      String url = "";
      String description = "";
      String prefix = "";
      String suffix = "";
 
      Value value = idxStream.popEntry ();
 
      while (value != null) {
	// parse the value now
	if (value.getKey ().equalsIgnoreCase ("entry")) {
	  // if a new entry is about to start, add the current one
	  addEntry (entry,keywords,description,url,prefix,suffix);
 
	  entry = value.getValue ();
	  keywords = "";
	  url = "";
	  description = "";
	} else if (value.getKey ().equalsIgnoreCase ("keywords")) {
	  keywords += value.getValue ();
	} else if (value.getKey ().equalsIgnoreCase ("url")) {
	  // use prefix and suffix
	  url = prefix + value.getValue () + suffix;
	} else if (value.getKey ().equalsIgnoreCase ("description")) {
	  description = value.getValue ();
	} else if (value.getKey ().equalsIgnoreCase ("prefix")) {
	  prefix = value.getValue ();
	  Tracer.write ("using new URL prefix \"" + prefix + "\"\n");
	} else if (value.getKey ().equalsIgnoreCase ("suffix")) {
	  suffix = value.getValue ();
	  Tracer.write ("using new URL suffix \"" + suffix + "\"\n");
	} else if (value.getKey ().equalsIgnoreCase ("alias")) {
	  keywords += value.getValue ();
	}
	value = idxStream.popEntry ();
      }
 
      // the final entry just read
      addEntry (entry,keywords,description,url,prefix,suffix);
    } catch (MalformedURLException exc) {
      // an error occured while reading...
    }
 
    return;
  }
 
  
  /*----------------------------------------------------------------------------
    INTERFACE: 
    PURPOSE:   
  	      
    NOTES:     
  
    PARAMS:    
    THROWS:    
    RETURNS:   void
  
    HISTORY:   98-05-10: created
               98-06-01: value is "", not null if empty
  ----------------------------------------------------------------------------*/
  private void addEntry (String entry,String keywords,
			 String description,String url,
			 String prefix,String suffix)
  {
    // the entry must be set
    if (entry.length () == 0) {
      return;
    }
 
    // the keywords must be set, else ignore it
    if (keywords.length () != 0) {
      if (url.length () == 0) {
	// if the URL is empty, construct one following the rule:
	// URL = prefix + first keyword + suffix
	int endOfFirstKeyword = keywords.indexOf (" ");
	
	// because we have trimmed the string, the first character must
	// not be a blank
	if (endOfFirstKeyword >= 0) {
	  url = keywords.substring (0,endOfFirstKeyword);
	  Tracer.write ("constructing URL, keywords=\"" +
			keywords + "\"" +
			"using \"" + 
			url +
			"\" (results in \"" +
			prefix + url + suffix + "\")\n");
	} else {
	  // just a single keyword
	  url = keywords;
	  Tracer.write ("constructing URL, using keyword \"" + 
			url +
			"\" (results in \"" +
			prefix + url + suffix + "\")\n");
	}
	// add prefix and suffix
	url = prefix + url + suffix;
      }
      IndexEntry idxEntry =
	new IndexEntry (entry,keywords,description,url);
      iIndexTable.addElement (idxEntry);
    }
 
    return;
  }
 
 
  /*============================================================================
                             Instance Variables
  ============================================================================*/
  private IndexTable iIndexTable;
  private String     iSearchTerm;
  private int        iSearchMode;
 
 
  /*============================================================================
                                Static Data
  ============================================================================*/
 
  private static final String cIndexFile = "index.txt";
  private static final String cIndexKeyword = "INDEXFILE";
  private static final String cSearchKeyword = "SEARCHTERM";
}
 
/*==============================================================================
 
  HISTORY:
  
  $Log: SearchEngine.java,v $
  Revision 1.3  1999/08/10 09:56:03  ripley
  change FSF address in copyrights
  add some copyrights in src/gnome and elsewhere
 
  Revision 1.2  1999/03/04 17:15:18  leisch
  various bugfixes
 
  Revision 1.1.4.1  1999/03/02 15:19:57  leisch
  search used only kewords, no titles
 
  Revision 1.6  1998/05/19 20:23:13  baier
  added alias support
 
  Revision 1.5  1998/05/15 22:10:05  baier
  allow searching in description, fix bug in results list
 
  Revision 1.4  1998/05/10 22:56:53  baier
  internal search function, parameter expansion
 
  Revision 1.3  1998/05/10 02:44:32  baier
  traces, output in HTML via JavaScript, new index generation
 
  Revision 1.2  1998/04/26 22:36:34  baier
  documentation changes
 
 
 
  Revision 1.1  1998/04/26 21:32:54  baier
  Initial revision
 
 
==============================================================================*/
 
 
// Local Variables:
// mode: Java
// mode: font-lock
// End:

Rev 3765	Rev 5458
1	`/*==============================================================================`	1	`/*==============================================================================`
2		2
3	`Project: Simple JAVA Search Engine for Keyword Search`	3	`Project: Simple JAVA Search Engine for Keyword Search`
4		4
5	`JAVA Source file for the class SearchEngine`	5	`JAVA Source file for the class SearchEngine`
6		6
7	`COPYRIGHT (C), 1998, Thomas Baier`	7	`COPYRIGHT (C), 1998, Thomas Baier`
8		8
9	`* This program is free software; you can redistribute it and/or modify`	9	`* This program is free software; you can redistribute it and/or modify`
10	`* it under the terms of the GNU General Public License as published by`	10	`* it under the terms of the GNU General Public License as published by`
11	`* the Free Software Foundation; either version 2 of the License, or`	11	`* the Free Software Foundation; either version 2 of the License, or`
12	`* (at your option) any later version.`	12	`* (at your option) any later version.`
13	`*`	13	`*`
14	`* This program is distributed in the hope that it will be useful,`	14	`* This program is distributed in the hope that it will be useful,`
15	`* but WITHOUT ANY WARRANTY; without even the implied warranty of`	15	`* but WITHOUT ANY WARRANTY; without even the implied warranty of`
16	`* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the`	16	`* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the`
17	`* GNU General Public License for more details.`	17	`* GNU General Public License for more details.`
18	`*`	18	`*`
19	`* You should have received a copy of the GNU General Public License`	19	`* You should have received a copy of the GNU General Public License`
20	`* along with this program; if not, write to the Free Software`	20	`* along with this program; if not, write to the Free Software`
21	`* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.`	21	`* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA`
22		22
23	$Source: /scratch/CVS-ARCHIVE/R/doc/html/search/SearchEngine.java,v $	23	$Source: /scratch/CVS-ARCHIVE/R/doc/html/search/SearchEngine.java,v $
24		24
25	$Revision: 1.2 $	25	$Revision: 1.3 $
26		26
27	$Date: 1999/03/04 17:15:18 $	27	$Date: 1999/08/10 09:56:03 $
28		28
29	$Author: leisch $	29	$Author: ripley $
30		30
31	`==============================================================================*/`	31	`==============================================================================*/`
32		32
33		33
34	`/* -------------------------------- Imports --------------------------------- */`	34	`/* -------------------------------- Imports --------------------------------- */`
35		35
36	`import java.applet.*;`	36	`import java.applet.*;`
37	`import java.awt.*;`	37	`import java.awt.*;`
38	`import java.net.*;`	38	`import java.net.*;`
39	`import java.io.*;`	39	`import java.io.*;`
40	`import java.util.*;`	40	`import java.util.*;`
41		41
42		42
43	`/*==============================================================================`	43	`/*==============================================================================`
44	`Interface of class SearchEngine`	44	`Interface of class SearchEngine`
45	`==============================================================================*/`	45	`==============================================================================*/`
46		46
47	`/*------------------------------------------------------------------------------`	47	`/*------------------------------------------------------------------------------`
48	`CLASS: SearchEngine`	48	`CLASS: SearchEngine`
49	`SUPER: Applet`	49	`SUPER: Applet`
50	`CONF. TO:`	50	`CONF. TO:`
51	`PURPOSE:`	51	`PURPOSE:`
52	`NOTES:`	52	`NOTES:`
53		53
54	`HISTORY: 98-04-26: created`	54	`HISTORY: 98-04-26: created`
55	`98-05-15: new member for search mode`	55	`98-05-15: new member for search mode`
56	`------------------------------------------------------------------------------*/`	56	`------------------------------------------------------------------------------*/`
57	`public class SearchEngine extends Applet`	57	`public class SearchEngine extends Applet`
58	`{`	58	`{`
59	`/*============================================================================`	59	`/*============================================================================`
60	`Public methods`	60	`Public methods`
61	`============================================================================*/`	61	`============================================================================*/`
62		62
63	`/*----------------------------------------------------------------------------`	63	`/*----------------------------------------------------------------------------`
64	`INTERFACE:`	64	`INTERFACE:`
65	`PURPOSE: default constructor`	65	`PURPOSE: default constructor`
66		66
67	`NOTES:`	67	`NOTES:`
68		68
69	`PARAMS:`	69	`PARAMS:`
70	`THROWS:`	70	`THROWS:`
71	`RETURNS: void`	71	`RETURNS: void`
72		72
73	`HISTORY: 98-04-26: created`	73	`HISTORY: 98-04-26: created`
74	`98-05-03: now reads the index file`	74	`98-05-03: now reads the index file`
75	`98-05-15: init new member`	75	`98-05-15: init new member`
76	`----------------------------------------------------------------------------*/`	76	`----------------------------------------------------------------------------*/`
77	`public SearchEngine ()`	77	`public SearchEngine ()`
78	`{`	78	`{`
79	`iIndexTable = null;`	79	`iIndexTable = null;`
80	`iSearchTerm = null;`	80	`iSearchTerm = null;`
81	`iSearchMode = 0;`	81	`iSearchMode = 0;`
82		82
83	`Tracer.write ("SearchEngine initializing\n");`	83	`Tracer.write ("SearchEngine initializing\n");`
84		84
85	`return;`	85	`return;`
86	`}`	86	`}`
87		87
88		88
89	`/*----------------------------------------------------------------------------`	89	`/*----------------------------------------------------------------------------`
90	`INTERFACE:`	90	`INTERFACE:`
91	`PURPOSE: return general information about the applet`	91	`PURPOSE: return general information about the applet`
92		92
93	`NOTES:`	93	`NOTES:`
94		94
95	`PARAMS:`	95	`PARAMS:`
96	`THROWS:`	96	`THROWS:`
97	`RETURNS: String: the information`	97	`RETURNS: String: the information`
98		98
99	`HISTORY: 98-04-26: created`	99	`HISTORY: 98-04-26: created`
100	`----------------------------------------------------------------------------*/`	100	`----------------------------------------------------------------------------*/`
101	`public String getAppletInfo ()`	101	`public String getAppletInfo ()`
102	`{`	102	`{`
103	`return "Name: SearchEngine\r\n" +`	103	`return "Name: SearchEngine\r\n" +`
104	`"Author: Thomas Baier\r\n" +`	104	`"Author: Thomas Baier\r\n" +`
105	`"(C) 1998 Thomas Baier, ALL RIGHTS RESERVED";`	105	`"(C) 1998 Thomas Baier, ALL RIGHTS RESERVED";`
106	`}`	106	`}`
107		107
108		108
109	`/*----------------------------------------------------------------------------`	109	`/*----------------------------------------------------------------------------`
110	`INTERFACE:`	110	`INTERFACE:`
111	`PURPOSE: perform initialization`	111	`PURPOSE: perform initialization`
112		112
113	`NOTES: creates the controls`	113	`NOTES: creates the controls`
114		114
115	`PARAMS:`	115	`PARAMS:`
116	`THROWS:`	116	`THROWS:`
117	`RETURNS: void`	117	`RETURNS: void`
118		118
119	`HISTORY: 98-04-26: created`	119	`HISTORY: 98-04-26: created`
120	`98-05-03: now a do-nothing`	120	`98-05-03: now a do-nothing`
121	`----------------------------------------------------------------------------*/`	121	`----------------------------------------------------------------------------*/`
122	`public void init ()`	122	`public void init ()`
123	`{`	123	`{`
124	`resize(640, 240);`	124	`resize(640, 240);`
125		125
126	`// get the name of the index file`	126	`// get the name of the index file`
127	`String indexName = getParameter (cIndexKeyword);`	127	`String indexName = getParameter (cIndexKeyword);`
128	`String searchTerm = getParameter (cSearchKeyword);`	128	`String searchTerm = getParameter (cSearchKeyword);`
129		129
130	`Tracer.write ("Index file is \"" + indexName + "\"\n");`	130	`Tracer.write ("Index file is \"" + indexName + "\"\n");`
131	`Tracer.write ("Search term is \"" + searchTerm + "\"\n");`	131	`Tracer.write ("Search term is \"" + searchTerm + "\"\n");`
132		132
133	`// use a default index file if none specified`	133	`// use a default index file if none specified`
134	`if (indexName == null) {`	134	`if (indexName == null) {`
135	`indexName = cIndexFile;`	135	`indexName = cIndexFile;`
136	`}`	136	`}`
137		137
138	`iSearchTerm = searchTerm;`	138	`iSearchTerm = searchTerm;`
139		139
140	`/*`	140	`/*`
141	`* examine the URL to get the search term...`	141	`* examine the URL to get the search term...`
142	`*`	142	`*`
143	`* if the URL ends with ?SEARCHTERM=xxxxx we know, xxxxx is the search term`	143	`* if the URL ends with ?SEARCHTERM=xxxxx we know, xxxxx is the search term`
144	`*/`	144	`*/`
145	`{`	145	`{`
146	`URL url = getDocumentBase ();`	146	`URL url = getDocumentBase ();`
147	`String urlString = url.toString ();`	147	`String urlString = url.toString ();`
148	`int index = urlString.indexOf ("?" + cSearchKeyword + "=");`	148	`int index = urlString.indexOf ("?" + cSearchKeyword + "=");`
149		149
150	`Tracer.write ("URL is \"" + urlString + "\"\n");`	150	`Tracer.write ("URL is \"" + urlString + "\"\n");`
151		151
152	`// if found, take the rest as the search string`	152	`// if found, take the rest as the search string`
153	`if (index >= 0) {`	153	`if (index >= 0) {`
154	`iSearchTerm =`	154	`iSearchTerm =`
155	`urlString.substring (index + 2 + cSearchKeyword.length ());`	155	`urlString.substring (index + 2 + cSearchKeyword.length ());`
156	`Tracer.write ("found search term \"" + iSearchTerm + "\" in URL\n");`	156	`Tracer.write ("found search term \"" + iSearchTerm + "\" in URL\n");`
157	`}`	157	`}`
158	`}`	158	`}`
159		159
160	`readIndexFile (indexName);`	160	`readIndexFile (indexName);`
161		161
162	`return;`	162	`return;`
163	`}`	163	`}`
164		164
165		165
166	`/*----------------------------------------------------------------------------`	166	`/*----------------------------------------------------------------------------`
167	`INTERFACE:`	167	`INTERFACE:`
168	`PURPOSE: perform "destructor" code`	168	`PURPOSE: perform "destructor" code`
169		169
170	`NOTES: not required here`	170	`NOTES: not required here`
171		171
172	`PARAMS:`	172	`PARAMS:`
173	`THROWS:`	173	`THROWS:`
174	`RETURNS: void`	174	`RETURNS: void`
175		175
176	`HISTORY: 98-04-26: created`	176	`HISTORY: 98-04-26: created`
177	`----------------------------------------------------------------------------*/`	177	`----------------------------------------------------------------------------*/`
178	`public void destroy ()`	178	`public void destroy ()`
179	`{`	179	`{`
180	`return;`	180	`return;`
181	`}`	181	`}`
182		182
183		183
184	`/*----------------------------------------------------------------------------`	184	`/*----------------------------------------------------------------------------`
185	`INTERFACE:`	185	`INTERFACE:`
186	`PURPOSE: perform painting of the applet`	186	`PURPOSE: perform painting of the applet`
187		187
188	`NOTES: not required for our applet, controls do everything`	188	`NOTES: not required for our applet, controls do everything`
189		189
190	`PARAMS: Graphics g: the graphics context to draw on`	190	`PARAMS: Graphics g: the graphics context to draw on`
191	`THROWS:`	191	`THROWS:`
192	`RETURNS: void`	192	`RETURNS: void`
193		193
194	`HISTORY: 98-04-26: created`	194	`HISTORY: 98-04-26: created`
195	`----------------------------------------------------------------------------*/`	195	`----------------------------------------------------------------------------*/`
196	`public void paint (Graphics g)`	196	`public void paint (Graphics g)`
197	`{`	197	`{`
198		198
199	`return;`	199	`return;`
200	`}`	200	`}`
201		201
202		202
203	`/*----------------------------------------------------------------------------`	203	`/*----------------------------------------------------------------------------`
204	`INTERFACE:`	204	`INTERFACE:`
205	`PURPOSE: perform startup code everytime visiting the applet`	205	`PURPOSE: perform startup code everytime visiting the applet`
206		206
207	`NOTES:`	207	`NOTES:`
208		208
209	`PARAMS:`	209	`PARAMS:`
210	`THROWS:`	210	`THROWS:`
211	`RETURNS: void`	211	`RETURNS: void`
212		212
213	`HISTORY: 98-04-26: created`	213	`HISTORY: 98-04-26: created`
214	`98-05-10: start the tracer`	214	`98-05-10: start the tracer`
215	`----------------------------------------------------------------------------*/`	215	`----------------------------------------------------------------------------*/`
216	`public void start ()`	216	`public void start ()`
217	`{`	217	`{`
218	`Tracer.start ();`	218	`Tracer.start ();`
219	`return;`	219	`return;`
220	`}`	220	`}`
221		221
222		222
223	`/*----------------------------------------------------------------------------`	223	`/*----------------------------------------------------------------------------`
224	`INTERFACE:`	224	`INTERFACE:`
225	`PURPOSE: perform cleanup evertime the applet "loses" the focus`	225	`PURPOSE: perform cleanup evertime the applet "loses" the focus`
226		226
227	`NOTES:`	227	`NOTES:`
228		228
229	`PARAMS:`	229	`PARAMS:`
230	`THROWS:`	230	`THROWS:`
231	`RETURNS: void`	231	`RETURNS: void`
232		232
233	`HISTORY: 98-04-26: created`	233	`HISTORY: 98-04-26: created`
234	`98-05-10: stop the tracer`	234	`98-05-10: stop the tracer`
235	`----------------------------------------------------------------------------*/`	235	`----------------------------------------------------------------------------*/`
236	`public void stop ()`	236	`public void stop ()`
237	`{`	237	`{`
238	`Tracer.stop ();`	238	`Tracer.stop ();`
239	`return;`	239	`return;`
240	`}`	240	`}`
241		241
242		242
243	`/*----------------------------------------------------------------------------`	243	`/*----------------------------------------------------------------------------`
244	`INTERFACE:`	244	`INTERFACE:`
245	`PURPOSE: perform the search and return the search results as a string`	245	`PURPOSE: perform the search and return the search results as a string`
246		246
247	`NOTES:`	247	`NOTES:`
248		248
249	`PARAMS:`	249	`PARAMS:`
250	`THROWS:`	250	`THROWS:`
251	`RETURNS: void`	251	`RETURNS: void`
252		252
253	`HISTORY: 98-05-03: created`	253	`HISTORY: 98-05-03: created`
254	`98-05-08: new format for output`	254	`98-05-08: new format for output`
255	`98-05-09: added trace`	255	`98-05-09: added trace`
256	`98-05-10: now a front-end for search()`	256	`98-05-10: now a front-end for search()`
257	`98-05-15: new parameter for search-mode`	257	`98-05-15: new parameter for search-mode`
258	`----------------------------------------------------------------------------*/`	258	`----------------------------------------------------------------------------*/`
259	`public String search (String key,boolean searchTitles)`	259	`public String search (String key,boolean searchTitles)`
260	`{`	260	`{`
261	`iSearchTerm = key;`	261	`iSearchTerm = key;`
262		262
263	`if (searchTitles) {`	263	`if (searchTitles) {`
264	`iSearchMode = IndexTable.cSearchDescription;`	264	`iSearchMode = IndexTable.cSearchDescription;`
265	`} else {`	265	`} else {`
266	`iSearchMode = 0;`	266	`iSearchMode = 0;`
267	`}`	267	`}`
268		268
269	`return internalSearch ();`	269	`return internalSearch ();`
270	`}`	270	`}`
271		271
272		272
273	`/*----------------------------------------------------------------------------`	273	`/*----------------------------------------------------------------------------`
274	`INTERFACE:`	274	`INTERFACE:`
275	`PURPOSE: perform the search (back-end)`	275	`PURPOSE: perform the search (back-end)`
276		276
277	`NOTES:`	277	`NOTES:`
278		278
279	`PARAMS:`	279	`PARAMS:`
280	`THROWS:`	280	`THROWS:`
281	`RETURNS: void`	281	`RETURNS: void`
282		282
283	`HISTORY: 98-05-10: created`	283	`HISTORY: 98-05-10: created`
284	`98-05-15: forward search-mode`	284	`98-05-15: forward search-mode`
285	`----------------------------------------------------------------------------*/`	285	`----------------------------------------------------------------------------*/`
286	`public String internalSearch ()`	286	`public String internalSearch ()`
287	`{`	287	`{`
288	`Tracer.write ("Search for \"" + iSearchTerm + "\" started");`	288	`Tracer.write ("Search for \"" + iSearchTerm + "\" started");`
289		289
290	`Vector foundItems = null;`	290	`Vector foundItems = null;`
291		291
292	`if (iSearchTerm != null) {`	292	`if (iSearchTerm != null) {`
293	`foundItems = iIndexTable.search (iSearchTerm,iSearchMode);`	293	`foundItems = iIndexTable.search (iSearchTerm,iSearchMode);`
294	`} else {`	294	`} else {`
295	`foundItems = null;`	295	`foundItems = null;`
296	`}`	296	`}`
297		297
298	`String result = null;`	298	`String result = null;`
299		299
300	`// if nothing found, return a special string`	300	`// if nothing found, return a special string`
301	`if (foundItems == null) {`	301	`if (foundItems == null) {`
302	`result = "No matches for <b>\"" +`	302	`result = "No matches for <b>\"" +`
303	`iSearchTerm +`	303	`iSearchTerm +`
304	`"\"</b> have been found!<hr>";`	304	`"\"</b> have been found!<hr>";`
305	`} else {`	305	`} else {`
306	`Enumeration cursor = foundItems.elements ();`	306	`Enumeration cursor = foundItems.elements ();`
307		307
308	`result =`	308	`result =`
309	`"The search string was <b>\"" +`	309	`"The search string was <b>\"" +`
310	`iSearchTerm +`	310	`iSearchTerm +`
311	`"</b>\"" +`	311	`"</b>\"" +`
312	`"<hr>" +`	312	`"<hr>" +`
313	`"<dl>";`	313	`"<dl>";`
314		314
315	`while (cursor.hasMoreElements ()) {`	315	`while (cursor.hasMoreElements ()) {`
316	`IndexEntry entry = (IndexEntry) cursor.nextElement ();`	316	`IndexEntry entry = (IndexEntry) cursor.nextElement ();`
317		317
318	`/*`	318	`/*`
319	`* the format for every entry is`	319	`* the format for every entry is`
320	`*`	320	`*`
321	`* title`	321	`* title`
322	`* description`	322	`* description`
323	`*/`	323	`*/`
324		324
325	`result +=`	325	`result +=`
326	`"<dt><a href=\"" +`	326	`"<dt><a href=\"" +`
327	`entry.getURL () +`	327	`entry.getURL () +`
328	`"\">" +`	328	`"\">" +`
329	`entry.getTitle () +`	329	`entry.getTitle () +`
330	`"</a></dt>\n";`	330	`"</a></dt>\n";`
331	`result += "<dd>" + entry.getDescription () + "</dd>\n";`	331	`result += "<dd>" + entry.getDescription () + "</dd>\n";`
332	`}`	332	`}`
333		333
334	`result += "</dl>";`	334	`result += "</dl>";`
335	`}`	335	`}`
336		336
337	`return result;`	337	`return result;`
338	`}`	338	`}`
339		339
340		340
341	`/*============================================================================`	341	`/*============================================================================`
342	`Protected methods`	342	`Protected methods`
343	`============================================================================*/`	343	`============================================================================*/`
344		344
345	`/*============================================================================`	345	`/*============================================================================`
346	`Private methods`	346	`Private methods`
347	`============================================================================*/`	347	`============================================================================*/`
348		348
349	`/*----------------------------------------------------------------------------`	349	`/*----------------------------------------------------------------------------`
350	`INTERFACE:`	350	`INTERFACE:`
351	`PURPOSE: read the index file`	351	`PURPOSE: read the index file`
352		352
353	`NOTES:`	353	`NOTES:`
354		354
355	`PARAMS:`	355	`PARAMS:`
356	`THROWS:`	356	`THROWS:`
357	`RETURNS: void`	357	`RETURNS: void`
358		358
359	`HISTORY: 98-04-26: created`	359	`HISTORY: 98-04-26: created`
360	`98-05-08: now use an IndexStream`	360	`98-05-08: now use an IndexStream`
361	`98-05-10: also use prefix and suffix, build URL from first key`	361	`98-05-10: also use prefix and suffix, build URL from first key`
362	`98-05-19: add "Alias:" entry to keywords`	362	`98-05-19: add "Alias:" entry to keywords`
363	`98-06-01: bugfix: don't null the variables`	363	`98-06-01: bugfix: don't null the variables`
364	`----------------------------------------------------------------------------*/`	364	`----------------------------------------------------------------------------*/`
365	`private void readIndexFile (String idxFile)`	365	`private void readIndexFile (String idxFile)`
366	`{`	366	`{`
367	`// create the index table`	367	`// create the index table`
368	`iIndexTable = new IndexTable ();`	368	`iIndexTable = new IndexTable ();`
369		369
370	`URL baseURL = getCodeBase ();`	370	`URL baseURL = getCodeBase ();`
371		371
372	`// get the index file and parse its contents`	372	`// get the index file and parse its contents`
373	`try {`	373	`try {`
374	`URL idxFileURL = new URL (baseURL,idxFile);`	374	`URL idxFileURL = new URL (baseURL,idxFile);`
375		375
376	`// get an IndexStream object for ease of parsing`	376	`// get an IndexStream object for ease of parsing`
377	`IndexStream idxStream = new IndexStream (idxFileURL);`	377	`IndexStream idxStream = new IndexStream (idxFileURL);`
378		378
379	`// now start parsing...`	379	`// now start parsing...`
380		380
381	`/*`	381	`/*`
382	`* An entry consists of a title, keywords, an URL and a description.`	382	`* An entry consists of a title, keywords, an URL and a description.`
383	`* everything else is ignored. Every entry starts with the keyword`	383	`* everything else is ignored. Every entry starts with the keyword`
384	`* "Entry" (case is ignored)`	384	`* "Entry" (case is ignored)`
385	`*`	385	`*`
386	`* must-have entries are "Entry" and "Keywords"`	386	`* must-have entries are "Entry" and "Keywords"`
387	`*`	387	`*`
388	`* 98-06-01: bugfix: don't null the variables`	388	`* 98-06-01: bugfix: don't null the variables`
389	`*/`	389	`*/`
390	`String entry = "";`	390	`String entry = "";`
391	`String keywords = "";`	391	`String keywords = "";`
392	`String url = "";`	392	`String url = "";`
393	`String description = "";`	393	`String description = "";`
394	`String prefix = "";`	394	`String prefix = "";`
395	`String suffix = "";`	395	`String suffix = "";`
396		396
397	`Value value = idxStream.popEntry ();`	397	`Value value = idxStream.popEntry ();`
398		398
399	`while (value != null) {`	399	`while (value != null) {`
400	`// parse the value now`	400	`// parse the value now`
401	`if (value.getKey ().equalsIgnoreCase ("entry")) {`	401	`if (value.getKey ().equalsIgnoreCase ("entry")) {`
402	`// if a new entry is about to start, add the current one`	402	`// if a new entry is about to start, add the current one`
403	`addEntry (entry,keywords,description,url,prefix,suffix);`	403	`addEntry (entry,keywords,description,url,prefix,suffix);`
404		404
405	`entry = value.getValue ();`	405	`entry = value.getValue ();`
406	`keywords = "";`	406	`keywords = "";`
407	`url = "";`	407	`url = "";`
408	`description = "";`	408	`description = "";`
409	`} else if (value.getKey ().equalsIgnoreCase ("keywords")) {`	409	`} else if (value.getKey ().equalsIgnoreCase ("keywords")) {`
410	`keywords += value.getValue ();`	410	`keywords += value.getValue ();`
411	`} else if (value.getKey ().equalsIgnoreCase ("url")) {`	411	`} else if (value.getKey ().equalsIgnoreCase ("url")) {`
412	`// use prefix and suffix`	412	`// use prefix and suffix`
413	`url = prefix + value.getValue () + suffix;`	413	`url = prefix + value.getValue () + suffix;`
414	`} else if (value.getKey ().equalsIgnoreCase ("description")) {`	414	`} else if (value.getKey ().equalsIgnoreCase ("description")) {`
415	`description = value.getValue ();`	415	`description = value.getValue ();`
416	`} else if (value.getKey ().equalsIgnoreCase ("prefix")) {`	416	`} else if (value.getKey ().equalsIgnoreCase ("prefix")) {`
417	`prefix = value.getValue ();`	417	`prefix = value.getValue ();`
418	`Tracer.write ("using new URL prefix \"" + prefix + "\"\n");`	418	`Tracer.write ("using new URL prefix \"" + prefix + "\"\n");`
419	`} else if (value.getKey ().equalsIgnoreCase ("suffix")) {`	419	`} else if (value.getKey ().equalsIgnoreCase ("suffix")) {`
420	`suffix = value.getValue ();`	420	`suffix = value.getValue ();`
421	`Tracer.write ("using new URL suffix \"" + suffix + "\"\n");`	421	`Tracer.write ("using new URL suffix \"" + suffix + "\"\n");`
422	`} else if (value.getKey ().equalsIgnoreCase ("alias")) {`	422	`} else if (value.getKey ().equalsIgnoreCase ("alias")) {`
423	`keywords += value.getValue ();`	423	`keywords += value.getValue ();`
424	`}`	424	`}`
425	`value = idxStream.popEntry ();`	425	`value = idxStream.popEntry ();`
426	`}`	426	`}`
427		427
428	`// the final entry just read`	428	`// the final entry just read`
429	`addEntry (entry,keywords,description,url,prefix,suffix);`	429	`addEntry (entry,keywords,description,url,prefix,suffix);`
430	`} catch (MalformedURLException exc) {`	430	`} catch (MalformedURLException exc) {`
431	`// an error occured while reading...`	431	`// an error occured while reading...`
432	`}`	432	`}`
433		433
434	`return;`	434	`return;`
435	`}`	435	`}`
436		436
437		437
438	`/*----------------------------------------------------------------------------`	438	`/*----------------------------------------------------------------------------`
439	`INTERFACE:`	439	`INTERFACE:`
440	`PURPOSE:`	440	`PURPOSE:`
441		441
442	`NOTES:`	442	`NOTES:`
443		443
444	`PARAMS:`	444	`PARAMS:`
445	`THROWS:`	445	`THROWS:`
446	`RETURNS: void`	446	`RETURNS: void`
447		447
448	`HISTORY: 98-05-10: created`	448	`HISTORY: 98-05-10: created`
449	`98-06-01: value is "", not null if empty`	449	`98-06-01: value is "", not null if empty`
450	`----------------------------------------------------------------------------*/`	450	`----------------------------------------------------------------------------*/`
451	`private void addEntry (String entry,String keywords,`	451	`private void addEntry (String entry,String keywords,`
452	`String description,String url,`	452	`String description,String url,`
453	`String prefix,String suffix)`	453	`String prefix,String suffix)`
454	`{`	454	`{`
455	`// the entry must be set`	455	`// the entry must be set`
456	`if (entry.length () == 0) {`	456	`if (entry.length () == 0) {`
457	`return;`	457	`return;`
458	`}`	458	`}`
459		459
460	`// the keywords must be set, else ignore it`	460	`// the keywords must be set, else ignore it`
461	`if (keywords.length () != 0) {`	461	`if (keywords.length () != 0) {`
462	`if (url.length () == 0) {`	462	`if (url.length () == 0) {`
463	`// if the URL is empty, construct one following the rule:`	463	`// if the URL is empty, construct one following the rule:`
464	`// URL = prefix + first keyword + suffix`	464	`// URL = prefix + first keyword + suffix`
465	`int endOfFirstKeyword = keywords.indexOf (" ");`	465	`int endOfFirstKeyword = keywords.indexOf (" ");`
466		466
467	`// because we have trimmed the string, the first character must`	467	`// because we have trimmed the string, the first character must`
468	`// not be a blank`	468	`// not be a blank`
469	`if (endOfFirstKeyword >= 0) {`	469	`if (endOfFirstKeyword >= 0) {`
470	`url = keywords.substring (0,endOfFirstKeyword);`	470	`url = keywords.substring (0,endOfFirstKeyword);`
471	`Tracer.write ("constructing URL, keywords=\"" +`	471	`Tracer.write ("constructing URL, keywords=\"" +`
472	`keywords + "\"" +`	472	`keywords + "\"" +`
473	`"using \"" +`	473	`"using \"" +`
474	`url +`	474	`url +`
475	`"\" (results in \"" +`	475	`"\" (results in \"" +`
476	`prefix + url + suffix + "\")\n");`	476	`prefix + url + suffix + "\")\n");`
477	`} else {`	477	`} else {`
478	`// just a single keyword`	478	`// just a single keyword`
479	`url = keywords;`	479	`url = keywords;`
480	`Tracer.write ("constructing URL, using keyword \"" +`	480	`Tracer.write ("constructing URL, using keyword \"" +`
481	`url +`	481	`url +`
482	`"\" (results in \"" +`	482	`"\" (results in \"" +`
483	`prefix + url + suffix + "\")\n");`	483	`prefix + url + suffix + "\")\n");`
484	`}`	484	`}`
485	`// add prefix and suffix`	485	`// add prefix and suffix`
486	`url = prefix + url + suffix;`	486	`url = prefix + url + suffix;`
487	`}`	487	`}`
488	`IndexEntry idxEntry =`	488	`IndexEntry idxEntry =`
489	`new IndexEntry (entry,keywords,description,url);`	489	`new IndexEntry (entry,keywords,description,url);`
490	`iIndexTable.addElement (idxEntry);`	490	`iIndexTable.addElement (idxEntry);`
491	`}`	491	`}`
492		492
493	`return;`	493	`return;`
494	`}`	494	`}`
495		495
496		496
497	`/*============================================================================`	497	`/*============================================================================`
498	`Instance Variables`	498	`Instance Variables`
499	`============================================================================*/`	499	`============================================================================*/`
500	`private IndexTable iIndexTable;`	500	`private IndexTable iIndexTable;`

The R Project SVN R

(root)/trunk/doc/html/search/SearchEngine.java @ 6607 – Rev 3765 → 5458