Work on DAO example. Table per class strategy. Persist fixes.

dao/src/main/java/com/iluwatar/App.java

@@ -13,8 +13,10 @@ public class App {
     public static void persistData(WizardDao dao) {
     	Spell spell = new Spell("Fireball");
     	Spellbook spellbook = new Spellbook("Book of fire");
+    	spell.setSpellbook(spellbook);
     	spellbook.getSpells().add(spell);
     	Wizard wizard = new Wizard("Jugga");
+    	spellbook.setWizard(wizard);
     	wizard.getSpellbooks().add(spellbook);
     	dao.persist(wizard);
     }
@@ -23,6 +25,12 @@ public class App {
     	List<Wizard> wizards = dao.findAll();
     	for (Wizard w: wizards) {
     		System.out.println(w);
+    		for (Spellbook spellbook: w.getSpellbooks()) {
+    			System.out.println(spellbook);
+    			for (Spell spell: spellbook.getSpells()) {
+    				System.out.println(spell);
+    			}
+    		}
     	}
     }
 }

dao/src/main/java/com/iluwatar/BaseEntity.java

@@ -1,26 +1,13 @@
 package com.iluwatar;
 
-import javax.persistence.Column;
+import javax.persistence.Inheritance;
-import javax.persistence.Entity;
+import javax.persistence.InheritanceType;
-import javax.persistence.GeneratedValue;
+import javax.persistence.MappedSuperclass;
-import javax.persistence.Id;
 import javax.persistence.Version;
 
-@Entity
+@MappedSuperclass
+@Inheritance(strategy=InheritanceType.TABLE_PER_CLASS)
 public class BaseEntity {
-
-	@Id
-	@GeneratedValue
-	@Column(name = "ID")
-	private Long id;
-
-	public Long getId() {
-		return id;
-	}
-
-	public void setId(Long id) {
-		this.id = id;
-	}
 	
 	@Version
 	private Long version;

dao/src/main/java/com/iluwatar/DaoBase.java

@@ -27,7 +27,7 @@ public abstract class DaoBase<E extends BaseEntity> {
   	  		.setProperty("hibernate.connection.url", "jdbc:h2:mem:test;DB_CLOSE_DELAY=-1")
   	  		.setProperty("hibernate.current_session_context_class", "thread")
   	  		.setProperty("hibernate.show_sql", "true")
-  	  		.setProperty("hibernate.hbm2ddl.auto", "create")
+  	  		.setProperty("hibernate.hbm2ddl.auto", "create-drop")
   	  		.buildSessionFactory();
     	return sessionFactory;
 	}

dao/src/main/java/com/iluwatar/Spell.java

@@ -1,6 +1,11 @@
 package com.iluwatar;
 
+import javax.persistence.Column;
 import javax.persistence.Entity;
+import javax.persistence.GeneratedValue;
+import javax.persistence.Id;
+import javax.persistence.Inheritance;
+import javax.persistence.InheritanceType;
 import javax.persistence.JoinColumn;
 import javax.persistence.ManyToOne;
 import javax.persistence.Table;
@@ -19,8 +24,21 @@ public class Spell extends BaseEntity {
 		this.name = name;
 	}
 
+	@Id
+	@GeneratedValue
+	@Column(name = "SPELL_ID")
+	private Long id;
+
+	public Long getId() {
+		return id;
+	}
+
+	public void setId(Long id) {
+		this.id = id;
+	}
+	
 	@ManyToOne
-	@JoinColumn(name="SPELLBOOK_ID_FK", referencedColumnName="ID")
+	@JoinColumn(name="SPELLBOOK_ID_FK", referencedColumnName="SPELLBOOK_ID")
 	private Spellbook spellbook;
 	
 	public String getName() {
@@ -31,6 +49,14 @@ public class Spell extends BaseEntity {
 		this.name = name;
 	}
 	
+	public Spellbook getSpellbook() {
+		return spellbook;
+	}
+
+	public void setSpellbook(Spellbook spellbook) {
+		this.spellbook = spellbook;
+	}
+
 	@Override
 	public String toString() {
 		return name;

dao/src/main/java/com/iluwatar/Spellbook.java

@@ -4,7 +4,13 @@ import java.util.HashSet;
 import java.util.Set;
 
 import javax.persistence.CascadeType;
+import javax.persistence.Column;
 import javax.persistence.Entity;
+import javax.persistence.FetchType;
+import javax.persistence.GeneratedValue;
+import javax.persistence.Id;
+import javax.persistence.Inheritance;
+import javax.persistence.InheritanceType;
 import javax.persistence.JoinColumn;
 import javax.persistence.ManyToOne;
 import javax.persistence.OneToMany;
@@ -23,13 +29,26 @@ public class Spellbook extends BaseEntity {
 		this.name = name;
 	}
 
+	@Id
+	@GeneratedValue
+	@Column(name = "SPELLBOOK_ID")
+	private Long id;
+
+	public Long getId() {
+		return id;
+	}
+
+	public void setId(Long id) {
+		this.id = id;
+	}
+	
 	private String name;
 
 	@ManyToOne
-	@JoinColumn(name="WIZARD_ID_FK", referencedColumnName="ID")
+	@JoinColumn(name="WIZARD_ID_FK", referencedColumnName="WIZARD_ID")
 	private Wizard wizard;
 
-	@OneToMany(mappedBy = "spellbook", orphanRemoval = true, cascade = CascadeType.ALL)
+	@OneToMany(mappedBy = "spellbook", orphanRemoval = true, fetch = FetchType.EAGER, cascade = CascadeType.ALL)
 	private Set<Spell> spells;
 	
 	public String getName() {

dao/src/main/java/com/iluwatar/Wizard.java

@@ -4,7 +4,13 @@ import java.util.HashSet;
 import java.util.Set;
 
 import javax.persistence.CascadeType;
+import javax.persistence.Column;
 import javax.persistence.Entity;
+import javax.persistence.FetchType;
+import javax.persistence.GeneratedValue;
+import javax.persistence.Id;
+import javax.persistence.Inheritance;
+import javax.persistence.InheritanceType;
 import javax.persistence.OneToMany;
 import javax.persistence.Table;
 
@@ -20,10 +26,23 @@ public class Wizard extends BaseEntity {
 		this();
 		this.name = name;
 	}
+
+	@Id
+	@GeneratedValue
+	@Column(name = "WIZARD_ID")
+	private Long id;
+
+	public Long getId() {
+		return id;
+	}
+
+	public void setId(Long id) {
+		this.id = id;
+	}
 	
 	private String name;
 
-	@OneToMany(mappedBy = "wizard", orphanRemoval = true, cascade = CascadeType.ALL)
+	@OneToMany(mappedBy = "wizard", orphanRemoval = true, fetch = FetchType.EAGER, cascade = CascadeType.ALL)
 	private Set<Spellbook> spellbooks;
 	
 	public String getFirstName() {