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1 package com.db4o.f1.chapter2;
2
3 import java.io.File  ;
4
5 import com.db4o.Db4o;
6 import com.db4o.ObjectContainer;
7 import com.db4o.ObjectSet;
8 import com.db4o.f1.Util;
9 import com.db4o.query.Predicate;
10 import com.db4o.query.Query;
11
12
13 public class StructuredExample extends Util {
14 public static void main(String [] args) {
15 new File (Util.YAPFILENAME).delete();
16 ObjectContainer db=Db4o.openFile(Util.YAPFILENAME);
17 try {
18 storeFirstCar(db);
19 storeSecondCar(db);
20 retrieveAllCarsQBE(db);
21 retrieveAllPilotsQBE(db);
22 retrieveCarByPilotQBE(db);
23 retrieveCarByPilotNameQuery(db);
24 retrieveCarByPilotProtoQuery(db);
25 retrievePilotByCarModelQuery(db);
26 updateCar(db);
27 updatePilotSingleSession(db);
28 updatePilotSeparateSessionsPart1(db);
29 db.close();
30 db=Db4o.openFile(Util.YAPFILENAME);
31 updatePilotSeparateSessionsPart2(db);
32 db.close();
33 updatePilotSeparateSessionsImprovedPart1();
34 db=Db4o.openFile(Util.YAPFILENAME);
35 updatePilotSeparateSessionsImprovedPart2(db);
36 db.close();
37 db=Db4o.openFile(Util.YAPFILENAME);
38 updatePilotSeparateSessionsImprovedPart3(db);
39 deleteFlat(db);
40 db.close();
41 deleteDeepPart1();
42 db=Db4o.openFile(Util.YAPFILENAME);
43 deleteDeepPart2(db);
44 deleteDeepRevisited(db);
45 }
46 finally {
47 db.close();
48 }
49 }
50
51 public static void storeFirstCar(ObjectContainer db) {
52 Car car1=new Car("Ferrari");
53 Pilot pilot1=new Pilot("Michael Schumacher",100);
54 car1.setPilot(pilot1);
55 db.set(car1);
56 }
57
58 public static void storeSecondCar(ObjectContainer db) {
59 Pilot pilot2=new Pilot("Rubens Barrichello",99);
60 db.set(pilot2);
61 Car car2=new Car("BMW");
62 car2.setPilot(pilot2);
63 db.set(car2);
64 }
65
66 public static void retrieveAllCarsQBE(ObjectContainer db) {
67 Car proto=new Car(null);
68 ObjectSet result=db.get(proto);
69 listResult(result);
70 }
71
72 public static void retrieveAllPilotsQBE(ObjectContainer db) {
73 Pilot proto=new Pilot(null,0);
74 ObjectSet result=db.get(proto);
75 listResult(result);
76 }
77
78 public static void retrieveAllPilots(ObjectContainer db) {
79 ObjectSet result=db.get(Pilot.class);
80 listResult(result);
81 }
82
83 public static void retrieveCarByPilotQBE(
84 ObjectContainer db) {
85 Pilot pilotproto=new Pilot("Rubens Barrichello",0);
86 Car carproto=new Car(null);
87 carproto.setPilot(pilotproto);
88 ObjectSet result=db.get(carproto);
89 listResult(result);
90 }
91
92 public static void retrieveCarByPilotNameQuery(
93 ObjectContainer db) {
94 Query query=db.query();
95 query.constrain(Car.class);
96 query.descend("pilot").descend("name")
97 .constrain("Rubens Barrichello");
98 ObjectSet result=query.execute();
99 listResult(result);
100 }
101
102 public static void retrieveCarByPilotProtoQuery(
103 ObjectContainer db) {
104 Query query=db.query();
105 query.constrain(Car.class);
106 Pilot proto=new Pilot("Rubens Barrichello",0);
107 query.descend("pilot").constrain(proto);
108 ObjectSet result=query.execute();
109 listResult(result);
110 }
111
112 public static void retrievePilotByCarModelQuery(ObjectContainer db) {
113 Query carquery=db.query();
114 carquery.constrain(Car.class);
115 carquery.descend("model").constrain("Ferrari");
116 Query pilotquery=carquery.descend("pilot");
117 ObjectSet result=pilotquery.execute();
118 listResult(result);
119 }
120
121 public static void retrieveAllPilotsNative(ObjectContainer db) {
122 ObjectSet results = db.query(new Predicate() {
123 public boolean match(Pilot pilot){
124 return true;
125 }
126 });
127 listResult(results);
128 }
129
130
131 public static void retrieveAllCars(ObjectContainer db) {
132 ObjectSet results = db.get(Car.class);
133 listResult(results);
134 }
135
136 public static void retrieveCarsByPilotNameNative(ObjectContainer db) {
137 final String pilotName = "Rubens Barrichello";
138 ObjectSet results = db.query(new Predicate() {
139 public boolean match(Car car){
140 return car.getPilot().getName().equals(pilotName);
141 }
142 });
143 listResult(results);
144 }
145
146 public static void updateCar(ObjectContainer db) {
147 ObjectSet result=db.query(new Predicate() {
148 public boolean match(Car car){
149 return car.getModel().equals("Ferrari");
150 }
151 });
152 Car found=(Car)result.next();
153 found.setPilot(new Pilot("Somebody else",0));
154 db.set(found);
155 result=db.query(new Predicate() {
156 public boolean match(Car car){
157 return car.getModel().equals("Ferrari");
158 }
159 });
160 listResult(result);
161 }
162
163 public static void updatePilotSingleSession(
164 ObjectContainer db) {
165 ObjectSet result=db.query(new Predicate() {
166 public boolean match(Car car){
167 return car.getModel().equals("Ferrari");
168 }
169 });
170 Car found=(Car)result.next();
171 found.getPilot().addPoints(1);
172 db.set(found);
173 result=db.query(new Predicate() {
174 public boolean match(Car car){
175 return car.getModel().equals("Ferrari");
176 }
177 });
178 listResult(result);
179 }
180
181 public static void updatePilotSeparateSessionsPart1(
182 ObjectContainer db) {
183 ObjectSet result=db.query(new Predicate() {
184 public boolean match(Car car){
185 return car.getModel().equals("Ferrari");
186 }
187 });
188 Car found=(Car)result.next();
189 found.getPilot().addPoints(1);
190 db.set(found);
191 }
192
193 public static void updatePilotSeparateSessionsPart2(
194 ObjectContainer db) {
195 ObjectSet result=db.query(new Predicate() {
196 public boolean match(Car car){
197 return car.getModel().equals("Ferrari");
198 }
199 });
200 listResult(result);
201 }
202
203 public static void updatePilotSeparateSessionsImprovedPart1() {
204 Db4o.configure().objectClass("com.db4o.f1.chapter2.Car")
205 .cascadeOnUpdate(true);
206 }
207
208 public static void updatePilotSeparateSessionsImprovedPart2(
209 ObjectContainer db) {
210 ObjectSet result=db.query(new Predicate() {
211 public boolean match(Car car){
212 return car.getModel().equals("Ferrari");
213 }
214 });
215 Car found=(Car)result.next();
216 found.getPilot().addPoints(1);
217 db.set(found);
218 }
219
220 public static void updatePilotSeparateSessionsImprovedPart3(
221 ObjectContainer db) {
222 ObjectSet result=db.query(new Predicate() {
223 public boolean match(Car car){
224 return car.getModel().equals("Ferrari");
225 }
226 });
227 listResult(result);
228 }
229
230 public static void deleteFlat(ObjectContainer db) {
231 ObjectSet result=db.query(new Predicate() {
232 public boolean match(Car car){
233 return car.getModel().equals("Ferrari");
234 }
235 });
236 Car found=(Car)result.next();
237 db.delete(found);
238 result=db.get(new Car(null));
239 listResult(result);
240 }
241
242 public static void deleteDeepPart1() {
243 Db4o.configure().objectClass("com.db4o.f1.chapter2.Car")
244 .cascadeOnDelete(true);
245 }
246
247 public static void deleteDeepPart2(ObjectContainer db) {
248 ObjectSet result=db.query(new Predicate() {
249 public boolean match(Car car){
250 return car.getModel().equals("BMW");
251 }
252 });
253 Car found=(Car)result.next();
254 db.delete(found);
255 result=db.query(new Predicate() {
256 public boolean match(Car car){
257 return true;
258 }
259 });
260 listResult(result);
261 }
262
263 public static void deleteDeepRevisited(ObjectContainer db) {
264 ObjectSet result=db.query(new Predicate() {
265 public boolean match(Pilot pilot){
266 return pilot.getName().equals("Michael Schumacher");
267 }
268 });
269 if (!result.hasNext()) {
270 System.out.println("Pilot not found!");
271 return;
272 }
273 Pilot pilot=(Pilot)result.next();
274 Car car1=new Car("Ferrari");
275 Car car2=new Car("BMW");
276 car1.setPilot(pilot);
277 car2.setPilot(pilot);
278 db.set(car1);
279 db.set(car2);
280 db.delete(car2);
281 result=db.query(new Predicate() {
282 public boolean match(Car car){
283 return true;
284 }
285 });
286 listResult(result);
287 }
288
289 }
290 |
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Java API By Example, From Geeks To Geeks.