package net.petrikainulainen.springdata.jpa.todo; import org.apache.commons.lang3.builder.ToStringBuilder; import org.hibernate.annotations.Type; import org.springframework.data.annotation.CreatedBy; import org.springframework.data.annotation.CreatedDate; import org.springframework.data.annotation.LastModifiedBy; import org.springframework.data.annotation.LastModifiedDate; import org.springframework.data.jpa.domain.support.AuditingEntityListener; import javax.persistence.Column; import javax.persistence.Entity; import javax.persistence.EntityListeners; import javax.persistence.GeneratedValue; import javax.persistence.GenerationType; import javax.persistence.Id; import javax.persistence.Table; import javax.persistence.Version; import java.time.ZonedDateTime; import static net.petrikainulainen.springdata.jpa.common.PreCondition.isTrue; import static net.petrikainulainen.springdata.jpa.common.PreCondition.notEmpty; import static net.petrikainulainen.springdata.jpa.common.PreCondition.notNull; /** * This entity class contains the information of a single todo entry * and the methods that are used to create new todo entries and to modify * the information of an existing todo entry. * * @author Petri Kainulainen */ @Entity @EntityListeners(AuditingEntityListener.class) @Table(name = "todos") final class Todo { static final int MAX_LENGTH_DESCRIPTION = 500; static final int MAX_LENGTH_TITLE = 100; @Id @GeneratedValue(strategy = GenerationType.AUTO) private Long id; @Column(name = "created_by_user", nullable = false) @CreatedBy private String createdByUser; @Column(name = "creation_time", nullable = false) @Type(type = "org.jadira.usertype.dateandtime.threeten.PersistentZonedDateTime") @CreatedDate private ZonedDateTime creationTime; @Column(name = "description", length = MAX_LENGTH_DESCRIPTION) private String description; @Column(name = "modified_by_user", nullable = false) @LastModifiedBy private String modifiedByUser; @Column(name = "modification_time") @Type(type = "org.jadira.usertype.dateandtime.threeten.PersistentZonedDateTime") @LastModifiedDate private ZonedDateTime modificationTime; @Column(name = "title", nullable = false, length = MAX_LENGTH_TITLE) private String title; @Version private long version; /** * Required by Hibernate. */ private Todo() {} private Todo(Builder builder) { this.title = builder.title; this.description = builder.description; } static Builder getBuilder() { return new Builder(); } Long getId() { return id; } String getCreatedByUser() { return createdByUser; } ZonedDateTime getCreationTime() { return creationTime; } String getDescription() { return description; } String getModifiedByUser() { return modifiedByUser; } ZonedDateTime getModificationTime() { return modificationTime; } String getTitle() { return title; } long getVersion() { return version; } void update(String newTitle, String newDescription) { requireValidTitleAndDescription(newTitle, newDescription); this.title = newTitle; this.description = newDescription; } private void requireValidTitleAndDescription(String title, String description) { notNull(title, "Title cannot be null."); notEmpty(title, "Title cannot be empty."); isTrue(title.length() <= MAX_LENGTH_TITLE, "The maximum length of the title is <%d> characters.", MAX_LENGTH_TITLE ); isTrue((description == null) || (description.length() <= MAX_LENGTH_DESCRIPTION), "The maximum length of the description is <%d> characters.", MAX_LENGTH_DESCRIPTION ); } @Override public String toString() { return new ToStringBuilder(this) .append("createdByUser", this.createdByUser) .append("creationTime", this.creationTime) .append("description", this.description) .append("id", this.id) .append("modifiedByUser", this.modifiedByUser) .append("modificationTime", this.modificationTime) .append("title", this.title) .append("version", this.version) .toString(); } /** * This entity is so simple that you don't really need to use the builder pattern * (use a constructor instead). I use the builder pattern here because it makes * the code a bit more easier to read. */ static class Builder { private String description; private String title; private Builder() {} Builder description(String description) { this.description = description; return this; } Builder title(String title) { this.title = title; return this; } Todo build() { Todo build = new Todo(this); build.requireValidTitleAndDescription(build.getTitle(), build.getDescription()); return build; } } }