Sample


1   /*-
2    * See the file LICENSE for redistribution information.
3    *
4    * Copyright (c) 2002,2006 Oracle.  All rights reserved.
5    *
6    * $Id: Sample.java,v 1.18 2006/10/31 19:56:20 mark Exp $
7    */
8   
9   package collections.ship.tuple;
10  
11  import java.io.FileNotFoundException  ;
12  import java.util.Iterator  ;
13  import java.util.Set  ;
14  
15  import com.sleepycat.collections.TransactionRunner;
16  import com.sleepycat.collections.TransactionWorker;
17  import com.sleepycat.je.DatabaseException;
18  
19  /**
20   * Sample is the main entry point for the sample program and may be run as
21   * follows:
22   *
23   * <pre>
24   * java collections.ship.tuple.Sample
25   *      [-h <home-directory> ]
26   * </pre>
27   *
28   * <p> The default for the home directory is ./tmp -- the tmp subdirectory of
29   * the current directory where the sample is run. The home directory must exist
30   * before running the sample.  To recreate the sample database from scratch,
31   * delete all files in the home directory before running the sample.  </p>
32   *
33   * @author Mark Hayes
34   */
35  public class Sample {
36  
37      private SampleDatabase db;
38      private SampleViews views;
39  
40      /**
41       * Run the sample program.
42       */
43      public static void main(String  [] args) {
44  
45          System.out.println("\nRunning sample: " + Sample.class);
46  
47          // Parse the command line arguments.
48          //
49          String   homeDir = "./tmp";
50          for (int i = 0; i < args.length; i += 1) {
51              if (args[i].equals("-h") && i < args.length - 1) {
52                  i += 1;
53                  homeDir = args[i];
54              } else {
55                  System.err.println("Usage:\n java " + Sample.class.getName() +
56                     "\n  [-h <home-directory>]");
57                  System.exit(2);
58              }
59          }
60  
61          // Run the sample.
62          //
63          Sample sample = null;
64          try {
65              sample = new Sample(homeDir);
66              sample.run();
67          } catch (Exception   e) {
68              // If an exception reaches this point, the last transaction did not
69              // complete.  If the exception is RunRecoveryException, follow
70              // the Berkeley DB recovery procedures before running again.
71              e.printStackTrace();
72          } finally {
73              if (sample != null) {
74                  try {
75                      // Always attempt to close the database cleanly.
76                      sample.close();
77                  } catch (Exception   e) {
78                      System.err.println("Exception during database close:");
79                      e.printStackTrace();
80                  }
81              }
82          }
83      }
84  
85      /**
86       * Open the database and views.
87       */
88      private Sample(String   homeDir)
89          throws DatabaseException, FileNotFoundException   {
90  
91          db = new SampleDatabase(homeDir);
92          views = new SampleViews(db);
93      }
94  
95      /**
96       * Close the database cleanly.
97       */
98      private void close()
99          throws DatabaseException {
100 
101         db.close();
102     }
103 
104     /**
105      * Run two transactions to populate and print the database.  A
106      * TransactionRunner is used to ensure consistent handling of transactions,
107      * including deadlock retries.  But the best transaction handling mechanism
108      * to use depends on the application.
109      */
110     private void run()
111         throws Exception   {
112 
113         TransactionRunner runner = new TransactionRunner(db.getEnvironment());
114         runner.run(new PopulateDatabase());
115         runner.run(new PrintDatabase());
116     }
117 
118     /**
119      * Populate the database in a single transaction.
120      */
121     private class PopulateDatabase implements TransactionWorker {
122 
123         public void doWork()
124             throws Exception   {
125             addSuppliers();
126             addParts();
127             addShipments();
128         }
129     }
130 
131     /**
132      * Print the database in a single transaction.  All entities are printed
133      * and the indices are used to print the entities for certain keys.
134      *
135      * <p> Note the use of special iterator() methods.  These are used here
136      * with indices to find the shipments for certain keys.</p>
137      */
138     private class PrintDatabase implements TransactionWorker {
139 
140         public void doWork()
141             throws Exception   {
142             printValues("Parts",
143             views.getPartSet().iterator());
144             printValues("Suppliers",
145             views.getSupplierSet().iterator());
146             printValues("Suppliers for City Paris",
147                         views.getSupplierByCityMap().duplicates(
148                                             "Paris").iterator());
149             printValues("Shipments",
150             views.getShipmentSet().iterator());
151             printValues("Shipments for Part P1",
152                         views.getShipmentByPartMap().duplicates(
153                                             new PartKey("P1")).iterator());
154             printValues("Shipments for Supplier S1",
155                         views.getShipmentBySupplierMap().duplicates(
156                                             new SupplierKey("S1")).iterator());
157         }
158     }
159 
160     /**
161      * Populate the part entities in the database.  If the part set is not
162      * empty, assume that this has already been done.
163      */
164     private void addParts() {
165 
166         Set   parts = views.getPartSet();
167         if (parts.isEmpty()) {
168             System.out.println("Adding Parts");
169             parts.add(new Part("P1", "Nut", "Red",
170                    new Weight(12.0, Weight.GRAMS), "London"));
171             parts.add(new Part("P2", "Bolt", "Green",
172                    new Weight(17.0, Weight.GRAMS), "Paris"));
173             parts.add(new Part("P3", "Screw", "Blue",
174                    new Weight(17.0, Weight.GRAMS), "Rome"));
175             parts.add(new Part("P4", "Screw", "Red",
176                    new Weight(14.0, Weight.GRAMS), "London"));
177             parts.add(new Part("P5", "Cam", "Blue",
178                    new Weight(12.0, Weight.GRAMS), "Paris"));
179             parts.add(new Part("P6", "Cog", "Red",
180                    new Weight(19.0, Weight.GRAMS), "London"));
181         }
182     }
183 
184     /**
185      * Populate the supplier entities in the database.  If the supplier set is
186      * not empty, assume that this has already been done.
187      */
188     private void addSuppliers() {
189 
190         Set   suppliers = views.getSupplierSet();
191         if (suppliers.isEmpty()) {
192             System.out.println("Adding Suppliers");
193             suppliers.add(new Supplier("S1", "Smith", 20, "London"));
194             suppliers.add(new Supplier("S2", "Jones", 10, "Paris"));
195             suppliers.add(new Supplier("S3", "Blake", 30, "Paris"));
196             suppliers.add(new Supplier("S4", "Clark", 20, "London"));
197             suppliers.add(new Supplier("S5", "Adams", 30, "Athens"));
198         }
199     }
200 
201     /**
202      * Populate the shipment entities in the database.  If the shipment set
203      * is not empty, assume that this has already been done.
204      */
205     private void addShipments() {
206 
207         Set   shipments = views.getShipmentSet();
208         if (shipments.isEmpty()) {
209             System.out.println("Adding Shipments");
210             shipments.add(new Shipment("P1", "S1", 300));
211             shipments.add(new Shipment("P2", "S1", 200));
212             shipments.add(new Shipment("P3", "S1", 400));
213             shipments.add(new Shipment("P4", "S1", 200));
214             shipments.add(new Shipment("P5", "S1", 100));
215             shipments.add(new Shipment("P6", "S1", 100));
216             shipments.add(new Shipment("P1", "S2", 300));
217             shipments.add(new Shipment("P2", "S2", 400));
218             shipments.add(new Shipment("P2", "S3", 200));
219             shipments.add(new Shipment("P2", "S4", 200));
220             shipments.add(new Shipment("P4", "S4", 300));
221             shipments.add(new Shipment("P5", "S4", 400));
222         }
223     }
224 
225     /**
226      * Print the objects returned by an iterator of entity value objects.
227      */
228     private void printValues(String   label, Iterator   iterator) {
229 
230         System.out.println("\n--- " + label + " ---");
231         while (iterator.hasNext()) {
232             System.out.println(iterator.next().toString());
233         }
234     }
235 }
236
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