sort List of bean object in java alphabetically in ascending order

Question

Below is the bean class:

public class bean  {
    private String Name;

    public String getName() {
        return Name;
    }

    public void setName(String name) {
        Name = name;
    }



    @Override
    public String toString() {
        return "bean [Name=" + Name + "]";
    }
}

Below is my java class where i am trying to sort the list of beans in ascending order(i mean alphabetical order):

 public class Test{
    public static void main(String[] args) {
        bean b1 = new bean();
        bean b2 = new bean();
        bean b3 = new bean();
        List<bean> beanList = new ArrayList<bean>();
        b1.setName("b");
        b2.setName("a");
        b3.setName("Z");
        beanList.add(b1);
        beanList.add(b2);
        beanList.add(b3);

    }
}

i am unable to achieve the sorting of the bean value in alphabetical order like a,b,z. can anyone please suggest

Answer 1

You are sorting 2 times and that is more that what you need

1st Test doesnt need to implement comparable...

public class Test  {
    public static void main(String[] args) { 
        Bean b1 = new Bean();
        Bean b2 = new Bean();
        Bean b3 = new Bean();
        List<Bean> beanList = new ArrayList<Bean>();
        b1.setName("b");
        b2.setName("a");
        b3.setName("Z");
        beanList.add(b1);
        beanList.add(b2);
        beanList.add(b3);
        
        Collections.sort(beanList);
        System.out.println("finally " + beanList);
    }
}

and the bean class should compare the strings since that is the sort criteria

public class Bean implements Comparable<Bean> {
    private String Name;

    public String getName() {
        return Name;
    }

    public void setName(String name) {
        Name = name;
    }

    @Override
    public String toString() {
        return "bean [Name=" + Name + "]";
    }

    @Override
    public int compareTo(Bean o) {
        return o.getName().compareTo(this.getName());
    }
}

---

edit:

you can for sure add more than one field to the bean class, example: lastname or you can use an anonymous comparator and sort with yoor own criteria

Example with last name:

public class Bean implements Comparable<Bean> {
    private String name;
    private String lastName;

    public String getLastName() {
        return lastName;
    }

    public void setLastName(String lastName) {
        this.lastName = lastName;
    }

    public String getName() {
        return name;
    }

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

    @Override
    public String toString() {
        return "Bean [name=" + name + ", lastName=" + lastName + "]";
    }
 
    @Override
    public int compareTo(Bean o) {
        return this.getName().compareTo(o.getName());
    }
}