I have a LinkedHashMap and MyClass has 2 string variables I want to convert this to Json so that it can paresed in javascript Please share how to do this.
I have created this structure because i need to store the values of of table in the format of rowName, columnName and its value
Struture
Map<String,MyClass> dataMap = new LinkedHashMap<String,MyClass>();
MyClass{
String fieldName;
String fieldValue;
}
You can use the Jackson 2 library.
An example you can find here (third part):
import com.fasterxml.jackson.databind.ObjectMapper;
import java.io.File;
import java.io.IOException;
import java.math.BigDecimal;
import java.util.Arrays;
import java.util.HashMap;
import java.util.Map;
public class JacksonExample1 {
public static void main(String[] args) {
ObjectMapper mapper = new ObjectMapper();
Staff staff = createStaff();
try {
// Java objects to JSON file
mapper.writeValue(new File("c:\\test\\staff.json"), staff);
// Java objects to JSON string - compact-print
String jsonString = mapper.writeValueAsString(staff);
System.out.println(jsonString);
// Java objects to JSON string - pretty-print
String jsonInString2 = mapper.writerWithDefaultPrettyPrinter().writeValueAsString(staff);
System.out.println(jsonInString2);
} catch (IOException e) {
e.printStackTrace();
}
}
private static Staff createStaff() {
Staff staff = new Staff();
staff.setName("mkyong");
staff.setAge(38);
staff.setPosition(new String[]{"Founder", "CTO", "Writer"});
Map<String, BigDecimal> salary = new HashMap() {{
put("2010", new BigDecimal(10000));
put("2012", new BigDecimal(12000));
put("2018", new BigDecimal(14000));
}};
staff.setSalary(salary);
staff.setSkills(Arrays.asList("java", "python", "node", "kotlin"));
return staff;
}
}
To resume you create an ObjectMapper then you can write an object to a file with mapper.writeValue or to a string with mapper.writeValueAsString.
you can use a JSON library to do it. You can use the org.json library. This answer will help you Convert from LinkedHashMap to json string
