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1 package com.db4o.f1.chapter1;
2
3
4 import java.io.File  ;
5
6 import com.db4o.Db4o;
7 import com.db4o.ObjectContainer;
8 import com.db4o.ObjectSet;
9 import com.db4o.f1.Util;
10
11
12 public class FirstStepsExample extends Util {
13 public static void main(String [] args) {
14 new File (Util.YAPFILENAME).delete();
15 accessDb4o();
16 new File (Util.YAPFILENAME).delete();
17 ObjectContainer db=Db4o.openFile(Util.YAPFILENAME);
18 try {
19 storeFirstPilot(db);
20 storeSecondPilot(db);
21 retrieveAllPilots(db);
22 retrievePilotByName(db);
23 retrievePilotByExactPoints(db);
24 updatePilot(db);
25 deleteFirstPilotByName(db);
26 deleteSecondPilotByName(db);
27 }
28 finally {
29 db.close();
30 }
31 }
32
33 public static void accessDb4o() {
34 ObjectContainer db=Db4o.openFile(Util.YAPFILENAME);
35 try {
36 }
38 finally {
39 db.close();
40 }
41 }
42
43 public static void storeFirstPilot(ObjectContainer db) {
44 Pilot pilot1=new Pilot("Michael Schumacher",100);
45 db.set(pilot1);
46 System.out.println("Stored "+pilot1);
47 }
48
49 public static void storeSecondPilot(ObjectContainer db) {
50 Pilot pilot2=new Pilot("Rubens Barrichello",99);
51 db.set(pilot2);
52 System.out.println("Stored "+pilot2);
53 }
54
55 public static void retrieveAllPilotQBE(ObjectContainer db) {
56 Pilot proto=new Pilot(null,0);
57 ObjectSet result=db.get(proto);
58 listResult(result);
59 }
60
61 public static void retrieveAllPilots(ObjectContainer db) {
62 ObjectSet result=db.get(Pilot.class);
63 listResult(result);
64 }
65
66 public static void retrievePilotByName(ObjectContainer db) {
67 Pilot proto=new Pilot("Michael Schumacher",0);
68 ObjectSet result=db.get(proto);
69 listResult(result);
70 }
71
72 public static void retrievePilotByExactPoints(ObjectContainer db) {
73 Pilot proto=new Pilot(null,100);
74 ObjectSet result=db.get(proto);
75 listResult(result);
76 }
77
78 public static void updatePilot(ObjectContainer db) {
79 ObjectSet result=db.get(new Pilot("Michael Schumacher",0));
80 Pilot found=(Pilot)result.next();
81 found.addPoints(11);
82 db.set(found);
83 System.out.println("Added 11 points for "+found);
84 retrieveAllPilots(db);
85 }
86
87 public static void deleteFirstPilotByName(ObjectContainer db) {
88 ObjectSet result=db.get(new Pilot("Michael Schumacher",0));
89 Pilot found=(Pilot)result.next();
90 db.delete(found);
91 System.out.println("Deleted "+found);
92 retrieveAllPilots(db);
93 }
94
95 public static void deleteSecondPilotByName(ObjectContainer db) {
96 ObjectSet result=db.get(new Pilot("Rubens Barrichello",0));
97 Pilot found=(Pilot)result.next();
98 db.delete(found);
99 System.out.println("Deleted "+found);
100 retrieveAllPilots(db);
101 }
102 }
103 |
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Java API By Example, From Geeks To Geeks.