How to display nested tree with some object on jsp

Question

I want to display on my jsp something like this

CategoryParent1
-----Subcategory1
-----Subcategory2
CategoryParent2
-----Subcategory1
-----Subcategory2

In which way i can solve it? Does spring-mvc has some library for it? Or i must use some external libraries?

I have a Category model

@Entity
public class Category {
@Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
private Integer id;
private String name;
@ManyToOne
private Category parentCategory;
@OneToMany(mappedBy = "parentCategory", cascade = CascadeType.ALL)
private List<Category> childCategories = new ArrayList<>();

public Category() {
}

public Category(String name){
    this.name = name;
}

public Category(String name, Category parentCategory) {
    this.name = name;
    this.parentCategory = parentCategory;
}

public Integer getId() {
    return id;
}

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

public String getName() {
    return name;
}

public void setName(String name) {
    this.name = name;
}

public Category getParentCategory() {
    return parentCategory;
}

public void setParentCategory(Category parentCategory) {
    this.parentCategory = parentCategory;
}

public List<Category> getChildCategories() {
    return childCategories;
}

public void setChildCategories(List<Category> childCategories) {
    this.childCategories = childCategories;
}
}

score 1 · Accepted Answer · edited May 23 '17 at 11:58

I have done the similar task but with recursive query. Here is the link

If you don't want to use recursive query. here is what you need to do.

Eagerly fetch child categories (see hibernate eager fetch| lazy load)
Remove the "sub query" which is inside the "main query" and remove the recursing statement of a function
If you have successfully created relationship, you can just get its children categories by using your "getchildrencategories" method.
It is your choice whether you use recursive function or not.

And do not use List its better to use Set:

@OneToMany(fetch = FetchType.EAGER, mappedBy="parentCategory", cascade=CascadeType.REMOVE, orphanRemoval=true )
private Set<Categories> childCategories = new HashSet<Categories>();

How to display nested tree with some object on jsp

1 Answers1