使用Groovy JsonBuilder将Java Object转换为JSON

Question

I am trying to convert Java Object to JSON using Groovy JsonBuilder

Java POJO Class

public class Employee {

    String name;

    int age;

    @Override
    public String toString() {
        return "Employee{" +
                "name='" + name + '\'' +
                ", age=" + age +
                '}';
    }
}

Groovy Script

Employee employee = new Employee();
employee.name="Vinod"
employee.age=24

println new JsonBuilder( employee ).toPrettyString()

Output

{

}

I am not sure if I am using JsonBuilder incorrectly. Please help

Answer 1

Since you are using a Java POJO, you need to add the getters for the two properties you have, ie, public String getName() and public String getAge() .

The JsonBuilder leverages DefaultGroovyMethods.getProperties to get object properties. If you don't add the aforementioned getters, it does not find any properties and therefore the resulting JSON is empty.

So that:

Employee.java

public class Employee {
    String name;
    int age;

    public String getName() {
        return name;
    }

    public int getAge() {
        return age;
    }

    @Override
    public String toString() {
        return String.format("Employee{name=%s, age=%d}", name, age);
    }
}

If you use a POGO instead (Plain Old Groovy Object), getters are added by default for each property, so it works out of the box: