Maven dependency -
<dependency>
<groupId>com.fasterxml.jackson.core</groupId>
<artifactId>jackson-databind</artifactId>
<version>2.9.6</version>
</dependency>
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How can we read only specific properties(nodes) from json in java - using Jackson Api
import java.io.IOException;
import com.fasterxml.jackson.core.JsonGenerationException;
import com.fasterxml.jackson.databind.JsonMappingException;
import com.fasterxml.jackson.databind.JsonNode;
import com.fasterxml.jackson.databind.ObjectMapper;
public class ConvertJsonToJavaObject {
public static void main(String[] args) {
try {
ObjectMapper objectMapper = new ObjectMapper();
// Convert JSON string to java Object
String jsonInString = "{\"empId\":11,\"emp_name\":\"Ankit\",\"address\":[\"Paris\",\"London\"]}";
JsonNode rootNode = objectMapper.readTree(jsonInString);
//READ empId
System.out.println("1. empId value = "+rootNode.get("empId") + ", empId type = "+rootNode.get("empId").getNodeType());
//OR
JsonNode empId = rootNode.path("empId");
System.out.println("1. empId value = "+empId + ", empId type = "+empId.getNodeType());
//READ emp_name
System.out.println("\n2.emp_name value = "+rootNode.get("emp_name") + ", emp_name type = "+rootNode.get("emp_name").getNodeType());
//READ address
System.out.println("\n3.address value = "+rootNode.get("address") + ", address type = "+rootNode.get("address").getNodeType());
} catch (JsonGenerationException e) {
e.printStackTrace();
} catch (JsonMappingException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
}
}
//output
/*
1. empId value = 11, empId type = NUMBER
1. empId value = 11, empId type = NUMBER
2.emp_name value = "Ankit", emp_name type = STRING
3.address value = ["Paris","London"], address type = ARRAY
*/
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Related links >
1. Jackson JSON -
We can use Jackson api for for processing JSON in java.
Jackson JSON examples
2. Java provides API (JSR 353) for Processing JSON (JSR 353).
It provides -
- Object Model API
- Streaming API
Java API for JSON processing examples >