java.lang.IllegalStateException: During synchronization a new object was found through a relationship that was not marked cascade PERSIST - jpa

Question

I have two 2 classes in relation many to many.
#Entity
#Table(name = "recipies")
public class Recipie implements Serializable {
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
private Long id;
private String name;
private String url;
private String image;
#ManyToMany
#JoinTable(
name = "recipie_ingredients",
joinColumns = {
#JoinColumn(name = "recipie_id", referencedColumnName = "id")},
inverseJoinColumns = {
#JoinColumn(name = "ingredient_id", referencedColumnName = "id")})
private List<Ingredient> ingredients = new ArrayList<>();
#Entity
#Table(name = "ingredients")
public class Ingredient implements Serializable {
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
private Integer id;
private String name;
#ManyToMany(mappedBy = "ingredients")
private List<Recipie> recipies;
I would like to create a new recipie this way:
List<Ingredient> ingredientsList = new ArrayList<>();
String ingredientName = "example";
Ingredient ingredient = ingredientsDao.findIngredientByName(ingredientName);
if (ingredient == null) {
ingredient = new Ingredient();
ingredient.setName(ingredientName);
}
ingredientsList.add(ingredient);
.....
recipie.setIngredients(ingredientsList);
recipiesDao.addRecipie(recipie);
If ingredient doesn't exist in database, occur errors like this
Caused by: java.lang.IllegalStateException: During synchronization a new object was found through a relationship that was not marked cascade PERSIST
Is there any way to Ingredient objects created in the table automatically?
I try add CascadeType.PERSIST but It also doesn't work
#ManyToMany(mappedBy = "ingredients", cascade = CascadeType.PERSIST)
private List<Recipie> recipies;

Answer 1

First of all, for a bidirectional relationship, both sides need to be updated, so:
recipe.getIngredients().add(ingredient);
ingredient.getRecipes().add(recipe);
Then, you can set the cascade to PERSIST on the side of the relationship which you are passing to save(). So if you are saving the recipe, you should mark the Recipe.ingredients with
#ManyToMany(cascade = CascadeType.PERSIST)
(Side note, it's spelled "recipe", not "recipie")

Answer 2

As mentioned by #Gimby, you need to assign both sides of the relationship.
When dealing with #Many... sided relationships I always initialise the collection (which you've done on one side):
#Entity
#Table(name = "recipies")
public class Recipie implements Serializable {
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
private Long id;
private String name;
private String url;
private String image;
#ManyToMany
#JoinTable(
name = "recipie_ingredients",
joinColumns = {
#JoinColumn(name = "recipie_id", referencedColumnName = "id")},
inverseJoinColumns = {
#JoinColumn(name = "ingredient_id", referencedColumnName = "id")})
private List<Ingredient> ingredients = new ArrayList<>();
...
}
#Entity
#Table(name = "ingredients")
public class Ingredient implements Serializable {
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
private Integer id;
private String name;
#ManyToMany(mappedBy = "ingredients")
private List<Recipie> recipies = new ArrayList<>();
...
}
And then a slight variation in your logic:
String ingredientName = "example";
Ingredient ingredient = ingredientsDao.findIngredientByName(ingredientName);
if (ingredient == null) {
ingredient = new Ingredient();
ingredient.setName(ingredientName);
}
...
// Don't forget to assign both sides of the relationship
recipe.getIngredients().add(ingredient);
ingredient.getRecipies().add(recipe);
recipiesDao.addRecipe(recipe);
This should then cascade persist/update correctly.
The real fun will begin when you try to figure out how to associate a quantity with the ingredient...