This is overly complicated, Jackson handles lists via its writer methods just as well as it handles regular objects. This should work just fine for you, assuming I have not misunderstood your question:

public void writeListToJsonArray() throws IOException {  
    final List<Event> list = new ArrayList<Event>(2);
    list.add(new Event("a1","a2"));
    list.add(new Event("b1","b2"));

    final ByteArrayOutputStream out = new ByteArrayOutputStream();
    final ObjectMapper mapper = new ObjectMapper();

    mapper.writeValue(out, list);

    final byte[] data = out.toByteArray();
    System.out.println(new String(data));
}
Answer from Perception on Stack Overflow
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TutorialsPoint
tutorialspoint.com โ€บ article โ€บ how-to-convert-a-list-to-json-array-using-the-jackson-library-in-java
How to convert a List to JSON array using the Jackson library in Java?
April 29, 2025 - import java.util.*; import com.fasterxml.jackson.databind.*; import com.fasterxml.jackson.databind.node.ArrayNode; public class ListToJSONArrayUsingArrayNode { public static void main(String[] args) { List < String > list = Arrays.asList("JAVA", "PYTHON", "SCALA", ".NET", "TESTING"); ObjectMapper objectMapper = new ObjectMapper(); ArrayNode arrayNode = objectMapper.createArrayNode(); for (String item: list) { arrayNode.add(item); // adding each item manually } try { String jsonArray = objectMapper.writeValueAsString(arrayNode); System.out.println(jsonArray); } catch (Exception e) { e.printStackTrace(); } } }
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Java Guides
javaguides.net โ€บ 2019 โ€บ 07 โ€บ convert-list-to-json-array-using-jackson.html
Convert List to JSON Array Using Jackson
July 21, 2019 - package net.javaguides.jackson; import java.util.ArrayList; import java.util.List; import com.fasterxml.jackson.core.JsonProcessingException; import com.fasterxml.jackson.databind.ObjectMapper; import com.fasterxml.jackson.databind.SerializationFeature; /** * Using Jackson API for list serialization and deserialization * @author ramesh fadatare * */ public class JacksonListToJson { public static void main(String[] args) throws JsonProcessingException { // Create ObjectMapper object.
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GeeksforGeeks
geeksforgeeks.org โ€บ java โ€บ how-to-convert-an-arraylist-of-objects-to-a-json-array-in-java
How to Convert an ArrayList of Objects to a JSON Array in Java? - GeeksforGeeks
July 23, 2025 - package org.example; import com.fasterxml.jackson.core.JsonProcessingException; import com.fasterxml.jackson.databind.ObjectMapper; import java.util.ArrayList; import java.util.List; public class Main { public static void main(String[] args) { // Create an ArrayList of objects List<Course> courses = new ArrayList<>(); courses.add( new Course(1, "Java", "25000", "3 Months")); courses.add( new Course(2, "C++", "20000", "3 Months")); // Convert the ArrayList to a JSON array ObjectMapper objectMapper = new ObjectMapper(); try { String jsonArray = objectMapper.writeValueAsString(courses); System.out.println(jsonArray); } catch (JsonProcessingException e) { e.printStackTrace(); } } }
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Mkyong
mkyong.com โ€บ home โ€บ java โ€บ how to parse json array with jackson
How to parse JSON Array with Jackson | mkyong.com
April 23, 2024 - package com.mkyong.json.jackson; import com.fasterxml.jackson.core.JsonProcessingException; import com.fasterxml.jackson.databind.ObjectMapper; import com.mkyong.json.model.Person; import java.util.Arrays; import java.util.HashMap; import java.util.List; import java.util.Map; public class JsonArrayToObjectExample3 { public static void main(String[] args) throws JsonProcessingException { // Create a list of Person objects List<Person> people = Arrays.asList( new Person("mkyong", 42), new Person("ah pig", 20) ); // Wrap the list in a Map with "Person" as the key Map<String, List<Person>> wrapper
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Baeldung
baeldung.com โ€บ home โ€บ java โ€บ java list โ€บ converting a java list to a json array
Converting a Java List to a Json Array | Baeldung
June 18, 2025 - After adding the required dependency, weโ€™ll use the ObjectMapper class from Jackson to convert the Java List to a JSON array as follows: @Test public void given_JavaList_whenUsingJacksonLibrary_thenOutJsonArray() throws JsonProcessingException ...
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Baeldung
baeldung.com โ€บ home โ€บ json โ€บ jackson โ€บ jackson โ€“ unmarshall to collection/array
Jackson - Unmarshall to Collection/Array | Baeldung
April 26, 2024 - If you want to dig deeper and learn other cool things you can do with the Jackson 2 โ€“ head on over to the main Jackson tutorial. ... @Test public void givenJsonArray_whenDeserializingAsArray_thenCorrect() throws JsonParseException, JsonMappingException, IOException { ObjectMapper mapper = new ObjectMapper(); List<MyDto> listOfDtos = Lists.newArrayList( new MyDto("a", 1, true), new MyDto("bc", 3, false)); String jsonArray = mapper.writeValueAsString(listOfDtos); // [{"stringValue":"a","intValue":1,"booleanValue":true}, // {"stringValue":"bc","intValue":3,"booleanValue":false}] MyDto[] asArray = mapper.readValue(jsonArray, MyDto[].class); assertThat(asArray[0], instanceOf(MyDto.class)); }
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CodingTechRoom
codingtechroom.com โ€บ question โ€บ efficiently-write-java-list-json-array-jackson
How to Efficiently Write a Java List as a JSON Array using Jackson - CodingTechRoom
Copied ยท ArrayList<Event> list ... Jackson to convert a Java ArrayList into a JSON array can be done efficiently with the `ObjectMapper` class....
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GeeksforGeeks
geeksforgeeks.org โ€บ java โ€บ convert-an-arraylist-into-a-json-string-in-java
How to Convert an ArrayList into a JSON String in Java? - GeeksforGeeks
July 23, 2025 - It creates an ArrayList of type String and adds 3 course names to it. It uses the ObjectMapper from Jackson to convert the ArrayList to a JSON string.
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Stack Abuse
stackabuse.com โ€บ converting-json-array-to-a-java-array-or-list
Convert JSON Array to a Java Array or List with Jackson
September 8, 2020 - Using Jackson's ObjectMapper class, it's easy to read values and map them to an object, or an array of objects. We just use the readValue() method, passing the JSON contents and the class we'd like to map to.
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YouTube
youtube.com โ€บ watch
Java json 01 create an arraylist to serialize with Jackson library - YouTube
Shows how to prepare an arraylist of a class. Preparing for use of a json library called Jackson. Part 1 of 3 for how to read and write json files using java
Published: January 29, 2019
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Attacomsian
attacomsian.com โ€บ blog โ€บ jackson-convert-json-array-to-from-java-list
Convert JSON array to a list using Jackson in Java
November 6, 2022 - In this short tutorial, youโ€™ll learn how to use the Jackson library to convert a JSON array string into a list of Java Objects and vice versa.
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YouTube
youtube.com โ€บ phcodegyan videos
Parse JSON to Java Object,ArrayList & Array Using Jackson Library - YouTube
This video shows how to parse json into Java Object,ArrayList and Array.Jackson Library has been used to achieve the same.At 0:37 secs , it's Maven based jav...
Published: July 31, 2021
Views: 22K
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How to do in Java
howtodoinjava.com โ€บ home โ€บ convert json array to list in java: jackson, gson, org.json
Convert JSON Array to List in Java: Jackson, Gson, Org.json
3 weeks ago - JsonMapper mapper = JsonMapper... JSONArray(json).toList() returns the strings as a List<Object>. Call writeValueAsString(list) on the Jackson mapper or toJson(list) on Gson....
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Attacomsian
attacomsian.com โ€บ blog โ€บ jackson-create-json-array
How to create a JSON array using Jackson
October 14, 2022 - Jackson is a popular open-source library for reading, writing, and parsing JSON data in Java.