AbstractBaseEntity.java

package de.flower.common.model.db.entity;

import de.flower.common.model.db.type.ObjectStatus;
import org.hibernate.annotations.Index;

import javax.persistence.Column;
import javax.persistence.EnumType;
import javax.persistence.Enumerated;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;
import javax.persistence.MappedSuperclass;
import javax.persistence.Transient;
import java.io.Serializable;
import java.util.Date;

/**
 * @author flowerrrr
 */
@MappedSuperclass
public abstract class AbstractBaseEntity implements Serializable, IEntity, IObjectStatusAware, Cloneable {

    /**
     * This constant is only needed for serialization purposes. It overwrites the default mechanism and so makes the BE longer binary compatible
     */
    private static final long serialVersionUID = 1L;

    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Long id;

    @Enumerated(EnumType.ORDINAL)
    @Column
    @Index(name = "ix_objectstatus")
    private ObjectStatus objectStatus;

    /**
     * Using default values is not so easy. See http://opensource.atlassian.com/projects/hibernate/browse/ANN-604.
     */
    @Column
    @Index(name = "ix_createDate")
    private Date createDate = new Date();

    /**
     * @Version ensures that hibernate will always update the value when saving an entity.
     */
    // @Version (would require to init all existing records with an value. until necessary feature is not used)
    @Column
    private Date updateDate;

    protected AbstractBaseEntity() {
        this.objectStatus = ObjectStatus.ACTIVE;
    }

    /**
     * Gets the id.
     *
     * @return the id
     */
    @Override
    public Long getId() {
        return id;
    }

    public void setId(Long id) {
        this.id = id;
    }

    /**
     * Returns true if this entity is transient (not saved yet).
     *
     * @return true, if checks if is transient
     */
    @Override
    public boolean isNew() {
        return (getId() == null);
    }

    public ObjectStatus getObjectStatus() {
        return this.objectStatus;
    }

    public void setObjectStatus(ObjectStatus objectStatus) {
        this.objectStatus = objectStatus;
    }

    public final boolean isActive() {
        return objectStatus == ObjectStatus.ACTIVE;
    }

    public final boolean isDeleted() {
        return objectStatus == ObjectStatus.DELETED;
    }

    public final boolean isFixed() {
        return objectStatus == ObjectStatus.FIXED;
    }

    public Date getCreateDate() {
        return createDate;
    }

    public void setCreateDate(final Date createDate) {
        this.createDate = createDate;
    }

    public Date getUpdateDate() {
        return updateDate;
    }

    public void setUpdateDate(final Date updateDate) {
        this.updateDate = updateDate;
    }

    @Override
    public String toString() {
        return "AbstractBaseEntity@" + super.hashCode() + "{" +
                "id=" + id +
                '}';
    }

    /**
     * The @Id fields are not copied.
     * Reason: you cannot copy a persistent object
     * with already existing primary key.
     *
     * @return
     */
    @Override
    public AbstractBaseEntity clone() {
        try {
            AbstractBaseEntity clone = (AbstractBaseEntity) super.clone();
            clone.setId(null);
            return clone;
        } catch (CloneNotSupportedException e) {
            throw new RuntimeException(e);
        }
    }

    /**
     * Update from object.
     *
     * @param other the other
     */
    public void updateFromObject(AbstractBaseEntity other) {
        throw new UnsupportedOperationException("Method must be implemented in subclass!");
    }

    /**
     * The equality object.
     */
    @Transient
    private Object equalityObject;

    /**
     * The following methods are taken from
     * http://forum.hibernate.org/viewtopic.php?p=2191778.
     *
     * @param other the other
     * @return true, if equals
     */
    @Override
    public boolean equals(Object other) {
        if ((this == other)) {
            return true;
        }

        if ((other == null)) {
            return false;
        }

        if (!(this.getClass().isInstance(other))) {
            return false;
        }

        AbstractBaseEntity castOther = (AbstractBaseEntity) other;

        if (this.getId() == null) {
            return false;
        }

        if (castOther.getId() == null) {
            return false;
        }

        boolean equals = ((this.getId() == castOther.getId()) || ((this.getId() != null)
                && (castOther.getId() != null) && this.getId().equals(
                castOther.getId())));

        return equals;
    }

    /* (non-Javadoc)
      * @see java.lang.Object#hashCode()
      */
    @Override
    public int hashCode() {
        Object o = getEqualityObject();

        if (o == this) {
            return super.hashCode();
        } else {
            return o.hashCode();
        }
    }

    /**
     * Gets the equality object.
     *
     * @return the equality object
     */
    private Object getEqualityObject() {
        if (equalityObject == null) {
            equalityObject = (getId() == null) ? this : getId();
        }

        return equalityObject;
    }
}