How to explicitly include properties during Serialization 

Flexjson is a lightweight java library for serializing and de-serializing java beans, maps, arrays and collections in JSON format. Get the latest binaries from https://sourceforge.net/projects/flexjson/. This requires the library flexjson-2.1.jar to be in classpath. Flexjson by default serializes the immediate fields but not the Collection Objects. The following example shows how to explicitly include Collections while serializing a Complex Object.

File Name  :   com/bethecoder/tutorials/flexjson/common/StudentClass.java

package com.bethecoder.tutorials.flexjson.common; import java.util.ArrayList; import java.util.List; public class StudentClass {   private String name;   private MyStudent studentLeader;   private List<MyStudent> students = new ArrayList<MyStudent>();      public StudentClass(String name) {     super();     this.name = name;   }   public String getName() {     return name;   }   public void setName(String name) {     this.name = name;   }   public List<MyStudent> getStudents() {     return students;   }   public MyStudent getStudentLeader() {     return studentLeader;   }   public void setStudentLeader(MyStudent studentLeader) {     this.studentLeader = studentLeader;   }    }

File Name  :   com/bethecoder/tutorials/flexjson/common/MyStudent.java

package com.bethecoder.tutorials.flexjson.common; import java.util.ArrayList; import java.util.Arrays; import java.util.Date; import java.util.List; public class MyStudent extends Student {   private List<String> phones = new ArrayList<String>();      public MyStudent(String firstName, String lastName,        int age, String hobby, Date dob) {     super(firstName, lastName, age, hobby, dob);   }   public MyStudent addPhones(String ... phoneNums) {     phones.addAll(Arrays.asList(phoneNums));     return this;   }      public List<String> getPhones() {     return phones;   }    }

File Name  :   com/bethecoder/tutorials/flexjson/tests/IncludePropertiesTest.java  Author  :   Sudhakar KV Email  :   [email protected]

package com.bethecoder.tutorials.flexjson.tests; import java.util.Date; import com.bethecoder.tutorials.flexjson.common.MyStudent; import com.bethecoder.tutorials.flexjson.common.StudentClass; import flexjson.JSONSerializer; public class IncludePropertiesTest {   /**    * @param args    */   public static void main(String[] args) {     StudentClass stdClass = new StudentClass("Maths Class");     MyStudent spl = new MyStudent("Sudhakar", "Kasireddi", 29, "Painting", new Date());     spl.addPhones("1111", "2222");     stdClass.setStudentLeader(spl);          stdClass.getStudents().add(         new MyStudent("Sriram", "Kasireddi", 2,            "Singing", new Date()).addPhones("3333", "4444"));          stdClass.getStudents().add(spl);          stdClass.getStudents().add(         new MyStudent("Anu", "Kasireddi", 28,           "Cooking", new Date()).addPhones("5555", "6666"));          //By default Flexjson serializes the immediate fields of that object.      //It's just a shallow representation of the object.      //All collections are not serialized by default.     JSONSerializer serializer = new JSONSerializer().prettyPrint(true);      String jsonStr = serializer.serialize(stdClass);     System.out.println(jsonStr);          jsonStr = serializer.include("students").serialize(stdClass);     System.out.println(jsonStr);          jsonStr = serializer.include("students.phones").serialize(stdClass);     System.out.println(jsonStr);   } }

{
    "class": "com.bethecoder.tutorials.flexjson.common.StudentClass",
    "name": "Maths Class",
    "studentLeader": {
        "age": 29,
        "class": "com.bethecoder.tutorials.flexjson.common.MyStudent",
        "dob": 1342078990079,
        "firstName": "Sudhakar",
        "hobby": "Painting",
        "lastName": "Kasireddi"
    }
}



{
    "class": "com.bethecoder.tutorials.flexjson.common.StudentClass",
    "name": "Maths Class",
    "studentLeader": {
        "age": 29,
        "class": "com.bethecoder.tutorials.flexjson.common.MyStudent",
        "dob": 1342078990079,
        "firstName": "Sudhakar",
        "hobby": "Painting",
        "lastName": "Kasireddi"
    },
    "students": [
        {
            "age": 2,
            "class": "com.bethecoder.tutorials.flexjson.common.MyStudent",
            "dob": 1342078990079,
            "firstName": "Sriram",
            "hobby": "Singing",
            "lastName": "Kasireddi"
        },
        {
            "age": 29,
            "class": "com.bethecoder.tutorials.flexjson.common.MyStudent",
            "dob": 1342078990079,
            "firstName": "Sudhakar",
            "hobby": "Painting",
            "lastName": "Kasireddi"
        },
        {
            "age": 28,
            "class": "com.bethecoder.tutorials.flexjson.common.MyStudent",
            "dob": 1342078990079,
            "firstName": "Anu",
            "hobby": "Cooking",
            "lastName": "Kasireddi"
        }
    ]
}



{
    "class": "com.bethecoder.tutorials.flexjson.common.StudentClass",
    "name": "Maths Class",
    "studentLeader": {
        "age": 29,
        "class": "com.bethecoder.tutorials.flexjson.common.MyStudent",
        "dob": 1342078990079,
        "firstName": "Sudhakar",
        "hobby": "Painting",
        "lastName": "Kasireddi"
    },
    "students": [
        {
            "age": 2,
            "class": "com.bethecoder.tutorials.flexjson.common.MyStudent",
            "dob": 1342078990079,
            "firstName": "Sriram",
            "hobby": "Singing",
            "lastName": "Kasireddi",
            "phones": [
                "3333",
                "4444"
            ]
        },
        {
            "age": 29,
            "class": "com.bethecoder.tutorials.flexjson.common.MyStudent",
            "dob": 1342078990079,
            "firstName": "Sudhakar",
            "hobby": "Painting",
            "lastName": "Kasireddi",
            "phones": [
                "1111",
                "2222"
            ]
        },
        {
            "age": 28,
            "class": "com.bethecoder.tutorials.flexjson.common.MyStudent",
            "dob": 1342078990079,
            "firstName": "Anu",
            "hobby": "Cooking",
            "lastName": "Kasireddi",
            "phones": [
                "5555",
                "6666"
            ]
        }
    ]
}