Convert POJO to a GSON to JSON - json

Question

I'm trying to send a JSON post request to https://graph.microsoft.com/v1.0/me/sendMail to send an email.
I created a POJO with getters and setters so I can set the json value dynamically.
SendEmail.java
import java.util.ArrayList;
import com.fasterxml.jackson.databind.ObjectMapper;
import com.fasterxml.jackson.annotation.JsonProperty;
public class SendEmail {
public class Body{
public String contentType;
public String content;
public void setContentType(String contentType) {
this.contentType = contentType;
}
public String getContentType() {
return contentType;
}
public void setContent(String content) {
this.content = content;
}
public String getContent() {
return content;
}
}
public class CcRecipient{
public EmailAddress emailAddress;
public void setEmailAddress(SendEmail.EmailAddress emailAddress) {
this.emailAddress = emailAddress;
}
public SendEmail.EmailAddress getEmailAddress() {
return emailAddress;
}
}
public class EmailAddress{
public String address;
public void setAddress(String address) {
this.address = address;
}
public String getAddress() {
return address;
}
}
public class Message{
public String subject;
public Body body;
public ArrayList<ToRecipient> toRecipients;
public ArrayList<CcRecipient> ccRecipients;
public void setSubject(String subject) {
this.subject = subject;
}
public String getSubject() {
return subject;
}
public void setBody(SendEmail.Body body) {
this.body = body;
}
public SendEmail.Body getBody() {
return body;
}
public void setToRecipients(ArrayList<SendEmail.ToRecipient> toRecipients) {
this.toRecipients = toRecipients;
}
public ArrayList<SendEmail.ToRecipient> getToRecipients() {
return toRecipients;
}
public void setCcRecipients(ArrayList<SendEmail.CcRecipient> ccRecipients) {
this.ccRecipients = ccRecipients;
}
public ArrayList<SendEmail.CcRecipient> getCcRecipients() {
return ccRecipients;
}
}
public class Root{
public Message message;
public String saveToSentItems;
public void setMessage(SendEmail.Message message) {
this.message = message;
}
public SendEmail.Message getMessage() {
return message;
}
public void setSaveToSentItems(String saveToSentItems) {
this.saveToSentItems = saveToSentItems;
}
public String getSaveToSentItems() {
return saveToSentItems;
}
}
public class ToRecipient{
public EmailAddress emailAddress;
public void setEmailAddress(SendEmail.EmailAddress emailAddress) {
this.emailAddress = emailAddress;
}
public SendEmail.EmailAddress getEmailAddress() {
return emailAddress;
}
}
}
Below is the test class. The jsonRequest is empty. How can I put the correct JSON values using my POJO?
Test.java
SendEmail sendEmail = new SendEmail();
SendEmail.Message message = sendEmail.new Message();
message.setSubject("Test subject");
SendEmail.Body body = sendEmail.new Body();
body.setContent("this is a test body on an email");
SendEmail.ToRecipient toRecipient = sendEmail.new ToRecipient();
SendEmail.EmailAddress emailAddress = sendEmail.new EmailAddress();
emailAddress.setAddress("dummyemail#outlook.com");
toRecipient.setEmailAddress(emailAddress);
String accessToken = connectEmail(); System.out.println("ACCESS TOKEN: "+accessToken);
HttpURLConnection connection = null;
Gson gson = new Gson();
String jsonRequest = gson.toJson(toRecipient);
try {
URL url = new URL("https://graph.microsoft.com/v1.0/me/sendMail");
connection = (HttpURLConnection) url.openConnection();
connection.setRequestMethod("POST");
connection.setRequestProperty("Authorization","Bearer "+accessToken);
connection.setRequestProperty("Content-Type", "application/json");
//connection.setRequestProperty("Accept", "text/plain");
connection.setUseCaches(false);
connection.setDoOutput(true);
try(OutputStream os = connection.getOutputStream()) {
System.out.println("jsonRequest: "+jsonRequest);
os.write(jsonRequest.getBytes());
}
} catch (Exception e) {
System.out.println("EXCEPTION SENDING EMAIL");
}
Below is the sample post request I need to write using values from the POJO.
{
"message": {
"subject": "Meet for lunch?",
"body": {
"contentType": "Text",
"content": "The new cafeteria is open."
},
"toRecipients": [
{
"emailAddress": {
"address": "frannis#contoso.onmicrosoft.com"
}
}
],
"ccRecipients": [
{
"emailAddress": {
"address": "danas#contoso.onmicrosoft.com"
}
}
]
},
"saveToSentItems": "false"
}