|
1
2
3 package com.db4odoc.f1.serialize;
4
5 import java.io.File  ;
6 import java.io.FileReader ;
7 import java.io.FileWriter ;
8
9 import com.db4o.Db4o;
10 import com.db4o.ObjectContainer;
11 import com.db4o.ObjectSet;
12 import com.db4odoc.f1.Util;
13 import com.thoughtworks.xstream.XStream;
14 import com.thoughtworks.xstream.io.xml.DomDriver;
15
16
17 public class SerializeExample extends Util {
18
19 public static String XMLFILENAME = "formula1.xml";
20
21 public static void main(String [] args) {
22 setObjects();
23 exportToXml();
24 importFromXml();
25 }
26
28 public static void setObjects(){
29 new File (Util.YAPFILENAME).delete();
30 ObjectContainer db = Db4o.openFile(Util.YAPFILENAME);
31 try {
32 Car car = new Car("BMW", new Pilot("Rubens Barrichello"));
33 db.set(car);
34 car = new Car("Ferrari", new Pilot("Michael Schumacher"));
35 db.set(car);
36 } finally {
37 db.close();
38 }
39 }
40
42 public static void exportToXml()
43 {
44 XStream xstream = new XStream(new DomDriver());
45 try {
46 FileWriter xmlFile = new FileWriter (XMLFILENAME);
47 ObjectContainer db = Db4o.openFile(Util.YAPFILENAME);
48 try
49 {
50 ObjectSet result = db.query(Car.class);
51 Car[] cars = new Car[result.size()];
52 for (int i = 0; i < result.size(); i++)
53 {
54 Car car = (Car)result.next();
55 cars[i] = car;
56 }
57 String xml = xstream.toXML(cars);
58 xmlFile.write("<?xml version=\"1.0\"?>\n"+xml);
59 xmlFile.close();
60 }
61 finally
62 {
63 db.close();
64 }
65 } catch (Exception ex){
66 System.out.println(ex.getMessage());
67 }
68 }
69
71 public static void importFromXml() {
72 new File (Util.YAPFILENAME).delete();
73 XStream xstream = new XStream(new DomDriver());
74 try {
75 FileReader xmlReader = new FileReader (XMLFILENAME);
76 Car[] cars = (Car[]) xstream.fromXML(xmlReader);
77 ObjectContainer db;
78 for (int i = 0; i < cars.length; i++) {
79 db = Db4o.openFile(Util.YAPFILENAME);
80 try {
81 Car car = (Car) cars[i];
82 db.set(car);
83 } finally {
84 db.close();
85 }
86 }
87 db = Db4o.openFile(Util.YAPFILENAME);
88 try {
89 ObjectSet result = db.query(Pilot.class);
90 listResult(result);
91 result = db.query(Car.class);
92 listResult(result);
93 } finally {
94 db.close();
95 }
96 xmlReader.close();
97 } catch (Exception ex) {
98 System.out.println(ex.getMessage());
99 }
100 }
101
103 public static void listResult(ObjectSet result) {
104 System.out.println(result.size());
105 while(result.hasNext()) {
106 System.out.println(result.next());
107 }
108 }
109
111 }
112 |
Popular Tags |
Java API By Example, From Geeks To Geeks.