Java Mail 面接の質問と回答

Question: How to show all header information of message using Java Mail api?

Answer: We will use method given below to retrieve all header information, this method returns Enumerations type.

public Enumeration getAllHeaders();


package com.withoutbook.common;

import javax.mail.*;
import javax.mail.internet.*;
import java.util.*;

public class AllHeaderClient {

public static void main(String[] args) throws Exception {
String host = "192.168.10.110";
String user = "arindam";
String password = "arindam";

// Get system properties
Properties properties = System.getProperties();

// Get the default Session object.
Session session = Session.getDefaultInstance(properties);

// Get a Store object that implements the specified protocol.
Store store = session.getStore("pop3");

//Connect to the current host using the specified username and password.
store.connect(host, user, password);

//Create a Folder object corresponding to the given name.
Folder folder = store.getFolder("inbox");

// Open the Folder.
folder.open(Folder.READ_ONLY);

Message[] messages = folder.getMessages();
for (int i = 0; i < messages.length; i++) {
System.out.println("------------ Message " + (i + 1) + " ------------");
// Here's the difference...
Enumeration headers = messages[i].getAllHeaders();
while (headers.hasMoreElements()) {
Header h = (Header) headers.nextElement();
System.out.println(h.getName() + ": " + h.getValue());
}
System.out.println();
}
}
}