Java如何使用两个类创建一组对象？

Question

我有一个逻辑问题需要理解，如何创建一个私有的居民对象集。这是我的两个班级：

package main;
import java.util.Set;


/**
 * @author 
 * @version 0.1
 *
 */
public class City {

    private String name;
    /**
    *HERE is my Problem*/   
    private Set<Inhabitants> Inhabitants {

    } 

    /**
     * standard cunstructor
     */
    public City(String n, ) {
        setName(n);
    }

    /**
     * Search a particular name of inhabitant
     * @return object of inhabitant
     */
    static Set<Inhabitants> Search(){
        return inhabitants;

    }

    /**
     * Creates a inhabitant object and 
     * add to the set of inhabitants of the city
     * 
     * @param name
     * @param datebirth
     * @param maritalStatus
     * @
     */
    public void Add(String name,String datebirth,String maritalStatus) {

    }
    /**
     * Return all inhabitants objects of the city
     * @return 
     */
    static Set<Inhabitants> ReturnAll(){
        return inhabitants; 
    }

    /**
     * Return city name
     * @return 
     */
    static Set<Inhabitants> ReturnCityName(){
        return inhabitants;
    }


    /**
     * @return the name
     */
    public String getName() {
    return name;
    }

    /**
     * @param name the name to set
     */
    public void setName(String name) {
        this.name = name;
    }

    /**
     * @return the inhabitants
     */
    public Set<Inhabitants> getInhabitants() {
        return inhabitants;
    }

    /**
     * @param inhabitants the inhabitants to set
     */
    public void setInhabitants(Set<Inhabitants> inhabitants) {
        this.inhabitants = inhabitants;
    }
}

package main;

/**
 * @version 0.1
 */
public class Inhabitants {

    private String name;
    private String datebirth;
    private Boolean maritalStatus;

    /**
     * standard constructor
     */
    public Inhabitants() {
    }

    /**
     * @return the name
     */
    public String getName() {
        return name;
    }

    /**
     * @param name the name to set
     */
    public void setName(String name) {
        this.name = name;
    }

    /**
     * @return the datebirth
     */
    public String getDatebirth() {
        return datebirth;
    }

    /**
     * @param datebirth the datebirth to set
     */
    public void setDatebirth(String datebirth) {
        this.datebirth = datebirth;
    }

    /**
     * @return the maritalStatus
     */
    public Boolean getMaritalStatus() {
        return maritalStatus;
    }

    /**
     * @param maritalStatus the maritalStatus to set
     */
    public void setMaritalStatus(Boolean maritalStatus) {
        this.maritalStatus = maritalStatus;
    }
}

Answer 1

这听起来像一个简单的问题。你并不需要这么多代码：

package collections;

/**
 * Person
 * @author Michael
 * @link  https://stackoverflow.com/questions/30958832/java-how-create-a-set-of-object-with-two-classes
 * @since 6/20/2015 5:06 PM
 */
public class Person {
    private final String name;

    public Person(String name) {
        if (name == null || name.trim().length() == 0) throw new IllegalArgumentException("name cannot be blank or null");
        this.name = name;
    }

    public String getName() {
        return name;
    }

    @Override
    public boolean equals(Object o) {
        if (this == o) return true;
        if (o == null || getClass() != o.getClass()) return false;

        Person person = (Person) o;

        return name.equals(person.name);

    }

    @Override
    public int hashCode() {
        return name.hashCode();
    }

    @Override
    public String toString() {
        final StringBuilder sb = new StringBuilder("Person{");
        sb.append("name='").append(name).append('\'');
        sb.append('}');
        return sb.toString();
    }
}

package collections;

import java.util.Collection;
import java.util.HashSet;
import java.util.Set;

/**
 * City
 * @author Michael
 * @link  https://stackoverflow.com/questions/30958832/java-how-create-a-set-of-object-with-two-classes
 * @since 6/20/2015 5:06 PM
 */
public class City {

    private Set<Person> inhabitants;

    public City(Collection<Person> inhabitants) {
        this.inhabitants = (inhabitants == null) ? new HashSet<Person>() : new HashSet<Person>(inhabitants);
    }

    public void addInhabitant(Person p) {
        if (p != null) {
            this.inhabitants.add(p);
        }
    }

    @Override
    public String toString() {
        final StringBuilder sb = new StringBuilder("City{");
        sb.append("inhabitants=").append(inhabitants);
        sb.append('}');
        return sb.toString();
    }
}