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stackoverflow.com › questions › 14228912 › how-to-convert-list-to-json-in-java

Use GSON library for that. Here is the sample code

List<String> foo = new ArrayList<String>();
foo.add("A");
foo.add("B");
foo.add("C");

String json = new Gson().toJson(foo );

Here is the maven dependency for Gson

<dependencies>
    <!--  Gson: Java to Json conversion -->
    <dependency>
        <groupId>com.google.code.gson</groupId>
        <artifactId>gson</artifactId>
        <version>2.2.2</version>
        <scope>compile</scope>
    </dependency>
</dependencies>

Or you can directly download jar from here and put it in your class path

http://code.google.com/p/google-gson/downloads/detail?name=gson-1.0.jar&can=4&q=

To send Json to client you can use spring or in simple servlet add this code

response.getWriter().write(json);

Answer from code_fish on Stack Overflow

Baeldung

baeldung.com › home › java › java list › converting a java list to a json array

Converting a Java List to a Json Array | Baeldung

June 18, 2025 - In the above test method, we create a Gson instance (gson) and then use the toJson() method to convert the articles List to a JSON array represented as a string. Finally, we utilize the Assert class to verify the equality of the output jsonArray ...

Stack Overflow

stackoverflow.com › questions › 14228912 › how-to-convert-list-to-json-in-java

How to convert List to Json in Java - Stack Overflow

Top answer

1 of 8

153

Use GSON library for that. Here is the sample code

List<String> foo = new ArrayList<String>();
foo.add("A");
foo.add("B");
foo.add("C");

String json = new Gson().toJson(foo );

Here is the maven dependency for Gson

<dependencies>
    <!--  Gson: Java to Json conversion -->
    <dependency>
        <groupId>com.google.code.gson</groupId>
        <artifactId>gson</artifactId>
        <version>2.2.2</version>
        <scope>compile</scope>
    </dependency>
</dependencies>

Or you can directly download jar from here and put it in your class path

http://code.google.com/p/google-gson/downloads/detail?name=gson-1.0.jar&can=4&q=

To send Json to client you can use spring or in simple servlet add this code

response.getWriter().write(json);

2 of 8

You need an external library for this.

JSONArray jsonA = JSONArray.fromObject(mybeanList);
System.out.println(jsonA);

Google GSON is one of such libraries

You can also take a look here for examples on converting Java object collection to JSON string.

Discussions

How to convert list data into json in java - Stack Overflow

I have a function which is returning Data as List in java class. Now as per my need, I have to convert it into Json Format. Below is my function code snippet: public static List More on stackoverflow.com

stackoverflow.com

How to convert List to Json String in java (com.amazonaws.util.json.JSONObject) - Stack Overflow

@VinaySawant Right, ObjectMapper is for Java -> JSON objects. You can just use toString(), changed my answer. – Florian Albrecht Commented Apr 4, 2018 at 12:18 ... List jsons = new ArrayList<>(); jsons.add(new JSONObject(ImmutableMap.of("Attribute", "EmailAddress", "Value", "[email ... More on stackoverflow.com

stackoverflow.com

How to parse json to get size of the list using jsonObject in java?

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r/javahelp

May 16, 2022

How to parse json to get size of the list from jsonObject using Java?

Google "How to parse JSON Java" will return plenty of guides - more useful and a larger resources then what a reddit comment can provide :) Most parsing libraries use common Java structures, so if the json object contains a list, then the list will most likely have a "size" method you can use. More on reddit.com

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