[Jackson API Examples] - How to Convert Java List Object to/from JSON String using Jackson?(Serialize and De-serialize)

#JavaInspires

Hi Guys,

Welcome to Java Inspires.

In this post, we will see how to serialize and de-serialize java List object using Jackson api.

Here, we are using ObjectMapper class from JAckson library and writeValueAsString method to convert serialize and readValue method to deserialize.

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How to Convert Java List Object to/from JSON String using Jackson?(Serialize and Deserialize)

MainApp.java

package com.javainspires;

import java.io.IOException;
import java.util.ArrayList;
import java.util.List;

import com.fasterxml.jackson.databind.ObjectMapper;
import com.fasterxml.jackson.databind.SerializationFeature;

/**
 * 
 * @author #JavaInspires
 *
 */
public class MainApp {

	public static void main(String[] args) throws IOException {
		// convert java list object to json string
		// create a list object
		List<String> sampleList = new ArrayList<String>();
		// add elements to list
		sampleList.add("C");
		sampleList.add("C++");
		sampleList.add("Java");
		sampleList.add("Python");
		sampleList.add("GOLang");

		// create object mapper
		ObjectMapper mapper = new ObjectMapper();
		mapper.enable(SerializationFeature.INDENT_OUTPUT);
		// convert list to string
		String listJson = mapper.writeValueAsString(sampleList);
		System.out.println("Java List objeect to JSON\n");
		System.out.println(listJson);

		// convert back to list object

		List<String> list1 = mapper.readValue(listJson.getBytes(), List.class);
		System.out.println("\nJSON String to Java List Object\n");
		// print this list
		list1.forEach(System.out::println);

	}
}

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Output:

Java List objeect to JSON

[ "C", "C++", "Java", "Python", "GOLang" ]

JSON String to Java List Object

C
C++
Java
Python
GOLang

pom.xml

<project xmlns="http://maven.apache.org/POM/4.0.0"
	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
	xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
	<modelVersion>4.0.0</modelVersion>
	<groupId>com.javainspires</groupId>
	<artifactId>jackson-examples</artifactId>
	<version>0.0.1-SNAPSHOT</version>

	<dependencies>

		<!-- https://mvnrepository.com/artifact/com.fasterxml.jackson.core/jackson-databind -->
		<dependency>
			<groupId>com.fasterxml.jackson.core</groupId>
			<artifactId>jackson-databind</artifactId>
			<version>2.12.2</version>
		</dependency>

	</dependencies>
</project>

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