Java Mail 面试题与答案

Question: Sample code for Reading message using Java Mail.

Answer: The Folder class declares methods that fetch, append, copy and delete messages. These are some of the methods used in the program.

System.getProperties() this method get the system properties.
Session.getDefaultInstance(properties) this method get the default Session object.
session.getStore("pop3") this method get a Store object that implements the pop3 protocol.
store.connect(host, user, password) Connect to the current host using the specified username and password.
store.getFolder("inbox") create a Folder object of the inbox.
folder.open(Folder.READ_ONLY) open the Folder.
folder.getMessages() get all messages for the folder.


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

public class ReadMail {

public static void main(String args[]) throws Exception {

String host = "192.168.10.110";
String user = "test";
String password = "test";

// 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[] message = folder.getMessages();

// Display message.
for (int i = 0; i < message.length; i++) {

System.out.println("------------ Message " + (i + 1) + " ------------");

System.out.println("SentDate : " + message[i].getSentDate());
System.out.println("From : " + message[i].getFrom()[0]);
System.out.println("Subject : " + message[i].getSubject());
System.out.print("Message : ");

InputStream stream = message[i].getInputStream();
while (stream.available() != 0) {
System.out.print((char) stream.read());
}
System.out.println();
}

folder.close(true);
store.close();
}
}