Json simple java jar

JSON.simple — Environment Setup

JSON.simple is a library for Java, so the very first requirement is to have JDK installed in your machine.

System Requirement

JDK	Memory	Disk Space	Operating System
1.5 or above.	No minimum requirement.	No minimum requirement.	No minimum requirement.

Step 1: Verify Java Installation in Your Machine

First of all, open the console and execute a java command based on the operating system you are working on.

OS	Task	Command
Windows	Open Command Console	c:\> java -version
Linux	Open Command Terminal	$ java -version
Mac	Open Terminal	machine: < joseph$ java -version

Let’s verify the output for all the operating systems −

Java(TM) SE Runtime Environment (build 1.8.0_101)

Java(TM) SE Runtime Environment (build 1.8.0_101)

Java(TM) SE Runtime Environment (build 1.8.0_101)

If you do not have Java installed on your system, then download the Java Software Development Kit (SDK) from the following link www.oracle.com. We are assuming Java 1.8.0_101 as the installed version for this tutorial.

Step 2: Set JAVA Environment

Set the JAVA_HOME environment variable to point to the base directory location where Java is installed on your machine. For example.

OS	Output
Windows	Set the environment variable JAVA_HOME to C:\Program Files\Java\jdk1.8.0_101
Linux	export JAVA_HOME = /usr/local/java-current
Mac	export JAVA_HOME = /Library/Java/Home

Append Java compiler location to the System Path.

OS	Output
Windows	Append the string C:\Program Files\Java\jdk1.8.0_101\bin at the end of the system variable, Path.
Linux	export PATH = $PATH:$JAVA_HOME/bin/
Mac	not required

Verify Java installation using the command java -version as explained above.

Step 3: Download JSON.simple Archive

Download the latest version of JSON.simple jar file from json-simple @ MVNRepository. At the time of writing this tutorial, we have downloaded json-simple-1.1.1.jar, and copied it into C:\>JSON folder.

OS	Archive name
Windows	json-simple-1.1.1.jar
Linux	json-simple-1.1.1.jar
Mac	json-simple-1.1.1.jar

Step 4: Set JSON_JAVA Environment

Set the JSON_JAVA environment variable to point to the base directory location where JSON.simple jar is stored on your machine. Let’s assuming we’ve stored json-simple-1.1.1.jar in the JSON folder.

Set the environment variable JSON_JAVA to C:\JSON

export JSON_JAVA = /usr/local/JSON

export JSON_JAVA = /Library/JSON

Step 5: Set CLASSPATH Variable

Set the CLASSPATH environment variable to point to the JSON.simple jar location.

Set the environment variable CLASSPATH to %CLASSPATH%;%JSON_JAVA%\json-simple-1.1.1.jar;.;

export CLASSPATH = $CLASSPATH:$JSON_JAVA/json-simple-1.1.1.jar:.

export CLASSPATH = $CLASSPATH:$JSON_JAVA/json-simple-1.1.1.jar:.

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JSON.simple – Read and Write JSON

JSON.simple is a lightweight JSON processing library that can be used to read and write JSON files and strings. The encoded/decoded JSON will be in full compliance with JSON specification (RFC4627).

JSON.simple library is pretty old and has not been updated since march, 2012. Google GSON library is a good option for reading and writing JSON.

In this Java JSON tutorial, we will first see a quick example of writing to a JSON file and then we will read JSON from the file.

• Full compliance with JSON specification (RFC4627).
• Supports encode, decode/parse and escape JSON.
• Easy to use by reusing Map and List interfaces.
• Supports streaming output of JSON text.
• High performance.
• No dependency on external libraries.

Update pom.xml with json-simple maven dependency.

 com.googlecode.json-simple json-simple 1.1.1 

To write JSON test into the file, we will be working with mainly two classes:

1. JSONArray : To write data in json arrays. Use its add() method to add objects of type JSONObject .
2. JSONObject : To write json objects. Use it’s put() method to populate fields.

After populating the above objects, use FileWriter instance to write the JSON file.

package com.howtodoinjava.demo.jsonsimple; import java.io.FileWriter; import java.io.IOException; import org.json.simple.JSONArray; import org.json.simple.JSONObject; public class WriteJSONExample < @SuppressWarnings("unchecked") public static void main( String[] args ) < //First Employee JSONObject employeeDetails = new JSONObject(); employeeDetails.put("firstName", "Lokesh"); employeeDetails.put("lastName", "Gupta"); employeeDetails.put("website", "howtodoinjava.com"); JSONObject employeeObject = new JSONObject(); employeeObject.put("employee", employeeDetails); //Second Employee JSONObject employeeDetails2 = new JSONObject(); employeeDetails2.put("firstName", "Brian"); employeeDetails2.put("lastName", "Schultz"); employeeDetails2.put("website", "example.com"); JSONObject employeeObject2 = new JSONObject(); employeeObject2.put("employee", employeeDetails2); //Add employees to list JSONArray employeeList = new JSONArray(); employeeList.add(employeeObject); employeeList.add(employeeObject2); //Write JSON file try (FileWriter file = new FileWriter("employees.json")) < //We can write any JSONArray or JSONObject instance to the file file.write(employeeList.toJSONString()); file.flush(); >catch (IOException e) < e.printStackTrace(); >> >

To read JSON from file, we will use the JSON file we created in the previous example.

1. First of all, we will create JSONParser instance to parse JSON file.
2. Use FileReader to read JSON file and pass it to parser.
3. Start reading the JSON objects one by one, based on their type i.e. JSONArray and JSONObject .

package com.howtodoinjava.demo.jsonsimple; import java.io.FileNotFoundException; import java.io.FileReader; import java.io.IOException; import org.json.simple.JSONArray; import org.json.simple.JSONObject; import org.json.simple.parser.JSONParser; import org.json.simple.parser.ParseException; public class ReadJSONExample < @SuppressWarnings("unchecked") public static void main(String[] args) < //JSON parser object to parse read file JSONParser jsonParser = new JSONParser(); try (FileReader reader = new FileReader("employees.json")) < //Read JSON file Object obj = jsonParser.parse(reader); JSONArray employeeList = (JSONArray) obj; System.out.println(employeeList); //Iterate over employee array employeeList.forEach( emp ->parseEmployeeObject( (JSONObject) emp ) ); > catch (FileNotFoundException e) < e.printStackTrace(); >catch (IOException e) < e.printStackTrace(); >catch (ParseException e) < e.printStackTrace(); >> private static void parseEmployeeObject(JSONObject employee) < //Get employee object within list JSONObject employeeObject = (JSONObject) employee.get("employee"); //Get employee first name String firstName = (String) employeeObject.get("firstName"); System.out.println(firstName); //Get employee last name String lastName = (String) employeeObject.get("lastName"); System.out.println(lastName); //Get employee website name String website = (String) employeeObject.get("website"); System.out.println(website); >>

[ >, > ] Lokesh Gupta howtodoinjava.com Brian Schultz example.com

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JSON.simple example – Read and write JSON

In this post,we will see how can we read and write JSON using json.simple.

Java JSON Tutorial Content:

JSON.simple, is a simple Java library for JSON processing, read and write JSON data and full compliance with JSON specification (RFC4627).

In this post,we will read and write JSON using JSON.simple.
Download JSON.simple jar from here.
Create a java project named “JSONSimpleExample”
Create a folder jars and paste downloaded jar json-simple-1.1.1.jar.
right click on project->Property->java build path->Add jars and then go to src->jars->json-simple-1.1.1.jar.

Click on ok.
Then you will see json-simple-1.1 jar added to your libraries and then click on ok

Write JSON to file:

Create a new class named “JSONSimpleWritingToFileExample.java” in src->org.arpit.java2blog

Run above program and you will get following output:

Read JSON to file:

Here we will read above created JSON file.
Create a new class named “JSONSimpleReadingFromFileExample.java” in src->org.arpit.java2blog

Run above program and you will get following output:

Project Structure:

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