Überschreiben von hashcode und equals-Methode in java?

sind Sie auf der Suche etwas wie die folgenden? Probieren Sie es einfach, wie aus Ihrer Frage, ich denke, Sie wollen, vergleichen Sie den Inhalt Ihrer Probe ebenfalls Klasse.

class Sample implements java.io.Serializable{

    //POJO with two fields and getters/setters

    private String name;
    private Integer id;

    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }
    public Integer getId() {
        return id;
    }
    public void setId(Integer id) {
        this.id = id;
    }

    //This POJO does not override equals() and hashCode()
}

public class Beta implements Comparable{
    private Sample sample;

    public Sample getSample() {
        return sample;
    }

    public void setSample(Sample sample) {
        this.sample = sample;
    }

    @Override
    public int compareTo(Object o) {

        if(!(o instanceof Beta)){
            return -1;
        }
        }if(((Beta)o).getSample().getName().equals(this.sample.getName())){
                return 0; //return true if names are equal
            }
            if(((Beta)o).getSample().getId().equals(this.sample.getId())){
            //if name are notequal and IDs are equal, do what you need to do
            }
        return -1;
    }

    public static void main(String[] args) {
        Beta b = new Beta();
        Sample s = new Sample();
        s.setId(10);
        s.setName("Name1");
        b.setSample(s);

        Beta b2 = new Beta();
        Sample s2 = new Sample();
        s2.setId(20);
        s2.setName("Name2");
        b2.setSample(s2);

        System.out.println(b2.compareTo(b));

        Beta b3 = new Beta();
        Sample s3 = new Sample();
        s3.setId(10);
        s3.setName("Name1");
        b3.setSample(s3);

        System.out.println(b3.compareTo(b));
    }
}

Übergeordneten Ansatz

class Sample implements java.io.Serializable{

    //POJO with two fields and getters/setters

    private String name;
    private Integer id;

    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }
    public Integer getId() {
        return id;
    }
    public void setId(Integer id) {
        this.id = id;
    }

    //This POJO does not override equals() and hashCode()
}

public class Beta /*implements Comparable*/{
    private Sample sample;

    public Sample getSample() {
        return sample;
    }

    public void setSample(Sample sample) {
        this.sample = sample;
    }

    @Override
    public boolean equals(Object obj) {
        if (obj == null) {
            return false;
        }
        if (getClass() != obj.getClass()) {
            return false;
        }
        final Beta other = (Beta) obj;

        if ((this.getSample() == null) && (other.getSample() == null)){
            return true;
        }
        if ((this.getSample().getId().equals(other.getSample().getId())) && (this.getSample().getName().equals(other.getSample().getName()))) {
            return true;
        }
        return false;
    }

    @Override
    public int hashCode() {
        int hash = 3;
        hash = 53 * hash + (this.getSample().getName() != null ? this.getSample().getName().hashCode() : 0);
        hash = 53 * hash + (this.getSample().getId() != null ? this.getSample().getId().hashCode() : 0);
        return hash;
    }


/*  @Override
    public int compareTo(Object o) {

        if(!(o instanceof Beta)){
            return -1;
        }
        if(((Beta)o).getSample().getId().equals(this.sample.getId()) && ((Beta)o).getSample().getName().equals(this.sample.getName())){
            return 0;
        }
        return -1;
    }*/

    public static void main(String[] args) {
        Beta b = new Beta();
        Sample s = new Sample();
        s.setId(10);
        s.setName("Name1");
        b.setSample(s);

        Beta b2 = new Beta();
        Sample s2 = new Sample();
        s2.setId(20);
        s2.setName("Name2");
        b2.setSample(s2);

        System.out.println(b2.equals(b));

        Beta b3 = new Beta();
        Sample s3 = new Sample();
        s3.setId(10);
        s3.setName("Name1");
        b3.setSample(s3);

        System.out.println(b3.equals(b));
    }

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