Here I am going to show you how to convert JSON to Java Object using Jackson.
JSON to Java object :
In the previous tutorials we have seen how to convert a Java object to JSON string, you can see the dependencies of Jackson their.
[java]
package com.onlinetutorialspoint.json;
import org.codehaus.jackson.map.ObjectMapper;
public class JSON_String_To_Java_Object {
public static void main(String[] a) {
ObjectMapper mapperObj = new ObjectMapper();
try {
Student studentObj2 = mapperObj.readValue(jsonString(),
Student.class);
System.out.println(studentObj2);
} catch (Exception e) {
e.printStackTrace();
}
}
public static String jsonString() {
String str = "{\"studentId\": 1001, \"studentName\": \"Rahul\","
+ "\"roleNumber\": \"105\",\"standard\": \"5th\"}";
return str;
}
}
[/java]
[box type=”success” align=”alignleft” class=”” width=”100%”]
Student [studentId=1001, studentName=Rahul, roleNumber=105, standard=5th]
[/box]
JSON to Java object Reading from File :
Here I am going to read JSON string from a file and converting as Java object.
json.txt
[text]
{
"studentId": 4001,
"studentName": "Santosh",
"roleNumber": "107",
"standard": "7th"
}
[/text]
Reading JSON string from above file and converting to Java object.
[java]
package com.onlinetutorialspoint.json;
import java.io.File;
import org.codehaus.jackson.map.ObjectMapper;
public class JSON_String_To_Java_Object {
public static void main(String[] a) {
ObjectMapper mapperObj = new ObjectMapper();
String filePath = "/json.txt";
try {
File file = new File(filePath);
Student studentObj = mapperObj.readValue(file, Student.class);
System.out.println(studentObj);
} catch (Exception e) {
e.printStackTrace();
}
}
}
[/java]
[box type=”success” align=”alignleft” class=”” width=”100%”]
Student [studentId=4001, studentName=Santosh, roleNumber=107, standard=7th]
[/box]
Happy Learning 🙂