多忙な Java 開発者のための db4o ガイド: 配列とコレクション

                
package com.tedneward.model;

public class Address
{
    public Address()
    {
    }
    
    public Address(String street, String city, String state, String zip)
    {
        this.street = street; this.city = city; 
        this.state = state; this.zip = zip;
    }
    
    public String toString()
    {
        return "[Address: " + 
                "street=" + street + " " +
                "city=" + city + " " +
                "state=" + state + " " +
                "zip=" + zip + "]";
    }
    
    public int hashCode()
    {
        return street.hashCode() & city.hashCode() &
            state.hashCode() & zip.hashCode();
    }
    
    public boolean equals(Object obj)
    {
        if (obj == this)
            return this;
            
        if (obj instanceof Address)
        {
            Address rhs = (Address)obj;
            
            return (this.street.equals(rhs.street) &&
                this.city.equals(rhs.city) &&
                this.state.equals(rhs.state) &&
                this.zip.equals(rhs.zip));
        }
        else
            return false;
    }
    
    public String getStreet() { return this.street; }
    public void setStreet(String value) { this.street = value; }
    
    public String getCity() { return this.city; }
    public void setCity(String value) { this.city = value; }
    
    public String getState() { return this.state; }
    public void setState(String value) { this.state = value; }
    
    public String getZip() { return this.zip; }
    public void setZip(String value) { this.zip = value; }
    
    private String street;
    private String city;
    private String state;
    private String zip;
}

                package com.tedneward.model;

import java.util.List;
import java.util.ArrayList;
import java.util.Iterator;

public class Person
{
    public Person()
    { }
    public Person(String firstName, String lastName, Gender gender, int age, Mood mood)
    {
        this.firstName = firstName;
        this.lastName = lastName;
        this.gender = gender;
        this.age = age;
        this.mood = mood;
    }
    
    public String getFirstName() { return firstName; }
    public void setFirstName(String value) { firstName = value; }
    
    public String getLastName() { return lastName; }
    public void setLastName(String value) { lastName = value; }

    public Gender getGender() { return gender; }
    
    public int getAge() { return age; }
    public void setAge(int value) { age = value; }
    
    public Mood getMood() { return mood; }
    public void setMood(Mood value) { mood = value; }

    public Person getSpouse() { return spouse; }
    public void setSpouse(Person value) { 
        // A few business rules
        if (spouse != null)
            throw new IllegalArgumentException("Already married!");
        
        if (value.getSpouse() != null && value.getSpouse() != this)
            throw new IllegalArgumentException("Already married!");
            
        spouse = value; 
        
        // Highly sexist business rule
        if (gender == Gender.FEMALE)
            this.setLastName(value.getLastName());

        // Make marriage reflexive, if it's not already set that way
        if (value.getSpouse() != this)
            value.setSpouse(this);
    }

    public Address getHomeAddress() { return addresses[0]; }
    public void setHomeAddress(Address value) { addresses[0] = value; }

    public Address getWorkAddress() { return addresses[1]; }
    public void setWorkAddress(Address value) { addresses[1] = value; }

    public Address getVacationAddress() { return addresses[2]; }
    public void setVacationAddress(Address value) { addresses[2] = value; }

    public Iterator<Person> getChildren() { return children.iterator(); }
    public Person haveBaby(String name, Gender gender) {
        // Business rule
        if (this.gender.equals(Gender.MALE))
            throw new UnsupportedOperationException("Biological impossibility!");
        
        // Another highly objectionable business rule
        if (getSpouse() == null)
            throw new UnsupportedOperationException("Ethical impossibility!");

        // Welcome to the world, little one!
        Person child = new Person(name, this.lastName, gender, 0, Mood.CRANKY);
            // Well, wouldn't YOU be cranky if you'd just been pushed out of
            // a nice warm place?!?

        // These are your parents...            
        child.father = this.getSpouse();
        child.mother = this;
        
        // ... and you're their new baby.
        // (Everybody say "Awwww....")
        children.add(child);
        this.getSpouse().children.add(child);

        return child;
    }
    
    public String toString()
    {
        return 
            "[Person: " +
            "firstName = " + firstName + " " +
            "lastName = " + lastName + " " +
            "gender = " + gender + " " +
            "age = " + age + " " + 
            "mood = " + mood + " " +
            (spouse != null ? "spouse = " + spouse.getFirstName() + " " : "") +
            "]";
    }
    
    public boolean equals(Object rhs)
    {
        if (rhs == this)
            return true;
        
        if (!(rhs instanceof Person))
            return false;
        
        Person other = (Person)rhs;
        return (this.firstName.equals(other.firstName) &&
                this.lastName.equals(other.lastName) &&
                this.gender.equals(other.gender) &&
                this.age == other.age);
    }
    
    private String firstName;
    private String lastName;
    private Gender gender;
    private int age;
    private Mood mood;
    private Person spouse;
    private Address[] addresses = new Address[3];
    private List<Person> children = new ArrayList<Person>();
    private Person mother;
    private Person father;
}

                
    
@Test public void testTheModel()
    {
        Person bruce = new Person("Bruce", "Tate", 
            Gender.MALE, 29, Mood.HAPPY);
        Person maggie = new Person("Maggie", "Tate", 
            Gender.FEMALE, 29, Mood.HAPPY);
        bruce.setSpouse(maggie);

        Person kayla = maggie.haveBaby("Kayla", Gender.FEMALE);

        Person julia = maggie.haveBaby("Julia", Gender.FEMALE);
        
        assertTrue(julia.getFather() == bruce);
        assertTrue(kayla.getFather() == bruce);
        assertTrue(julia.getMother() == maggie);
        assertTrue(kayla.getMother() == maggie);
        
        int n = 0;
        for (Iterator<Person> kids = bruce.getChildren(); kids.hasNext(); )
        {
            Person child = kids.next();
            
            if (n == 0) assertTrue(child == kayla);
            if (n == 1) assertTrue(child == julia);
            
            n++;
        }
    }
	

                
@Before public void prepareDatabase()
    {
        db = Db4o.openFile("persons.data");

        Person bruce = new Person("Bruce", "Tate", 
            Gender.MALE, 29, Mood.HAPPY);
        Person maggie = new Person("Maggie", "Tate", 
            Gender.FEMALE, 29, Mood.HAPPY);
        bruce.setSpouse(maggie);
        
        bruce.setHomeAddress(
            new Address("5 Maple Drive", "Austin",
                "TX", "12345"));
        bruce.setWorkAddress(
            new Address("5 Maple Drive", "Austin",
                "TX", "12345"));
        bruce.setVacationAddress(
            new Address("10 Wanahokalugi Way", "Oahu",
                "HA", "11223"));

        Person kayla = maggie.haveBaby("Kayla", Gender.FEMALE);
        kayla.setAge(8);

        Person julia = maggie.haveBaby("Julia", Gender.FEMALE);
        julia.setAge(6);
    
        db.set(bruce);
    
        db.commit();
    }

                
@Test public void testTheStorageOfAddresses()
    {
        List<Person> maleTates = 
            db.query(new Predicate<Person>() {
                public boolean match(Person candidate) {
                    return candidate.getLastName().equals("Tate") &&
                            candidate.getGender().equals(Gender.MALE);
                }
            });
        Person bruce = maleTates.get(0);

        Address homeAndWork = 
            new Address("5 Maple Drive", "Austin",
                "TX", "12345");
        Address vacation =
            new Address("10 Wanahokalugi Way", "Oahu",
                "HA", "11223");
                
        assertTrue(bruce.getHomeAddress().equals(homeAndWork));
        assertTrue(bruce.getWorkAddress().equals(homeAndWork));
        assertTrue(bruce.getVacationAddress().equals(vacation));
    }

    @Test public void testTheStorageOfChildren() 
    { 
        List<Person> maleTates = 
            db.query(new Predicate<Person>() {
                public boolean match(Person candidate) {
                    return candidate.getLastName().equals("Tate") &&
                            candidate.getGender().equals(Gender.MALE);
                }
            });
        Person bruce = maleTates.get(0);
        
        int n = 0;
        for (Iterator<Person> children = bruce.getChildren(); 
             children.hasNext();
            )
        {
            Person child = children.next();
            
            System.out.println(child);
            
            if (n==0) assertTrue(child.getFirstName().equals("Kayla"));
            if (n==1) assertTrue(child.getFirstName().equals("Julia"));
            
            n++;
        }
    }

                
@Test public void findTheGirls()
    {
        List<Person> girls = 
            db.query(new Predicate<Person>() {
                public boolean match(Person candidate) {
                    return candidate.getGender().equals(Gender.FEMALE);
                }
            });
        boolean maggieFound = false;
        boolean kaylaFound = false;
        boolean juliaFound = false;
        for (Person p : girls)
        {
            if (p.getFirstName().equals("Maggie"))
                maggieFound = true;
            if (p.getFirstName().equals("Kayla"))
                kaylaFound = true;
            if (p.getFirstName().equals("Julia"))
                juliaFound = true;
        }
        
        assertTrue(maggieFound);
        assertTrue(kaylaFound);
        assertTrue(juliaFound);
    }

                
@Test public void findJuliaAndHerMommy()
    {
        Person maggie = (Person) db.get(
                new Person("Maggie", "Tate", Gender.FEMALE, 0, null)).next();
        Person julia = (Person) db.get(
                new Person("Julia", "Tate", Gender.FEMALE, 0, null)).next();

        assertTrue(julia.getMother() == maggie);
    }

                
@Test public void kaylaHasABirthday()
    {
        Person maggie = (Person) db.get(
                new Person("Maggie", "Tate", Gender.FEMALE, 0, null)).next();
        Person kayla = (Person) db.get(
                new Person("Kayla", "Tate", Gender.FEMALE, 0, null)).next();

        kayla.setAge(kayla.getAge() + 1);
        int kaylasNewAge = kayla.getAge();
        
        db.set(maggie);

        db.close();

        db = Db4o.openFile("persons.data");

        kayla = (Person) db.get(
                new Person("Kayla", "Tate", Gender.FEMALE, 0, null)).next();
        assert(kayla.getAge() == kaylasNewAge);
    }