Javaでflexjsonを使用してオブジェクトのリストをシリアル化するにはどうすればよいですか？

import flexjson.JSONSerializer;
import java.util.*;
public class JsonSerializeListTest {
   public static void main(String[] args) {
      JSONSerializer serializer = new JSONSerializer().prettyPrint(true); // pretty print JSON
      Student s1 = new Student("Raja", "Ramesh", 28, "Hyderabad");
      Student s2 = new Student("Suresh", "Kumar", 30, "Chennai");
      Student s3 = new Student("Surya", "Krishna", 35, "Pune");
      List<Student> students = Arrays.asList(s1, s2, s3);
      String jsonStr = serializer.serialize(students);
      System.out.println(jsonStr);
   }
}
// Student class
class Student {
   private String firstName;
   private String lastName;
   private int age;
   private String address;
   public Student() {}
   public Student(String firstName, String lastName, int age, String address) {
      super();
      this.firstName = firstName;
      this.lastName = lastName;
      this.age = age;
      this.address = address;
   }
   public String getFirstName() {
      return firstName;
   }
   public String getLastName() {
      return lastName;
   }
   public int getAge() {
      return age;
   }
   public String getAddress() {
     return address;
   }
   public String toString() {
      return "Student[ " +
      "firstName = " + firstName +
      ", lastName = " + lastName +
      ", age = " + age +
      ", address = " + address +
      " ]";
   }
}

[
 {
    "address": "Hyderabad",
    "age": 28,
    "class": "Student",
    "firstName": "Raja",
    "lastName": "Ramesh"
 },
 {
    "address": "Chennai",
    "age": 30,
    "class": "Student",
    "firstName": "Suresh",
    "lastName": "Kumar"
 },
 {
    "address": "Pune",
    "age": 35,
    "class": "Student",
    "firstName": "Surya",
    "lastName": "Krishna"
 }
]