[Development|java] java parsing json

1. Use the Jackson library to parse JSON:
   In the Maven project, add the following dependencies to pom.xml:

<!-- Jackson Core -->
<dependency>
    <groupId>com.fasterxml.jackson.core</groupId>
    <artifactId>jackson-core</artifactId>
    <version>2.12.5</version>
</dependency>

<!-- Jackson Databind -->
<dependency>
    <groupId>com.fasterxml.jackson.core</groupId>
    <artifactId>jackson-databind</artifactId>
    <version>2.12.5</version>
</dependency>

Code example:

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

public class JsonParserUsingJackson {
    
    
    public static void main(String[] args) {
    
    
        String jsonString = "{\"name\": \"John\", \"age\": 30, \"email\": \"[email protected]\"}";

        try {
    
    
            ObjectMapper objectMapper = new ObjectMapper();
            JsonNode jsonNode = objectMapper.readTree(jsonString);

            String name = jsonNode.get("name").asText();
            int age = jsonNode.get("age").asInt();
            String email = jsonNode.get("email").asText();

            System.out.println("Name: " + name);
            System.out.println("Age: " + age);
            System.out.println("Email: " + email);
        } catch (Exception e) {
    
    
            e.printStackTrace();
        }
    }
}

2. Use the Gson library to parse JSON:
   add the following dependencies

<dependency>
    <groupId>com.google.code.gson</groupId>
    <artifactId>gson</artifactId>
    <version>2.8.9</version>
</dependency>

Sample code:

import com.google.gson.Gson;
import com.google.gson.JsonObject;

public class JsonParserUsingGson {
    
    
    public static void main(String[] args) {
    
    
        String jsonString = "{\"name\": \"John\", \"age\": 30, \"email\": \"[email protected]\"}";

        try {
    
    
            Gson gson = new Gson();
            JsonObject jsonObject = gson.fromJson(jsonString, JsonObject.class);

            String name = jsonObject.get("name").getAsString();
            int age = jsonObject.get("age").getAsInt();
            String email = jsonObject.get("email").getAsString();

            System.out.println("Name: " + name);
            System.out.println("Age: " + age);
            System.out.println("Email: " + email);
        } catch (Exception e) {
    
    
            e.printStackTrace();
        }
    }
}