mailuser.java

JAVA编程百例书中各章节的所有例子的源代码,包括套接字编程

package ch08.section08;

import javax.mail.*;
import javax.servlet.http.*;

/**
 * This class encapsulates a mail user and is used by the
 * SimpleMailReader servlet.
 */
public class MailUser
    implements HttpSessionBindingListener {
  Session m_session;
  boolean m_loggedIn;
  Store m_store;
  Folder m_inbox;
  String m_storeProtocol;
  String m_storeHost;
  String m_transportProtocol;
  String m_transportHost;
  String m_user;
  String m_fromName;

  /**
   * Creates a new SimpleMailUser
   */
  public MailUser() {
    // Create a default session
    java.util.Properties props = System.getProperties();
    m_session = Session.getDefaultInstance(props, null);
  }

  /**
   * Get the current session
   * @return The current session
   */
  public Session getSession() {
    return m_session;
  }

  /**
   * Gets the current inbox
   * @return The inbox
   */
  public Folder getInbox() {
    return m_inbox;
  }

  /**
   * Returns true if the current user is logged in
   * @return true if the current user is logged in
   */
  public boolean isLoggedIn() {
    return m_loggedIn;
  }

  /**
   * Gets the store protocol
   * @return The store protocol, such as POP3
   */
  public String getStoreProtocol() {
    return m_storeProtocol;
  }

  /**
   * Gets the store host
   * @return The store host name
   */
  public String getStoreHost() {
    return m_storeHost;
  }

  /**
   * Gets the transport protocol
   * @return The transport protocol, such as SMTP
   */
  public String getTransportProtocol() {
    return m_transportProtocol;
  }

  /**
   * Gets the transport host
   * @return The transport host name
   */
  public String getTransportHost() {
    return m_transportHost;
  }

  /**
   * Gets the current user name
   * @return The current user
   */
  public String getUser() {
    return m_user;
  }

  /**
   * Sets the last from address entered by the user
   * @param name The from address name
   */
  public void setFromName(String name) {
    m_fromName = name;
  }

  /**
   * Gets the last from address entered by the user
   * @return The from address name
   */
  public String getFromName() {
    return m_fromName;
  }

  /**
   * Returns the names of the currently available transport
   * protocols
   * @return An array of transport names
   */
  public String[] getTransportNames() {
    return getProtocolNames(Provider.Type.TRANSPORT);
  }

  /**
   * Returns the names of the currently available store
   * protocols
   * @return An array of store names
   */
  public String[] getStoreNames() {
    return getProtocolNames(Provider.Type.STORE);
  }

  /**
   * Logs on to the specified Mail store
   * @param store The store protocol
   * @param storeHost The store host name
   * @param transport The transport protocol
   * @param transportHost The transport host name
   * @param user The user name
   * @param password The user password
   */
  public void login(String store, String storeHost,
                    String transport, String transportHost,
                    String user, String password) throws MessagingException {
    try {

      // Create a new session
      close();
      java.util.Properties props = System.getProperties();
      props.put("mail.host", storeHost);
      m_session = Session.getDefaultInstance(props, null);

      // Create a new URLName
      URLName url = new URLName(store, storeHost, -1,
                                "INBOX", user, password);

      m_store = m_session.getStore(url);
      m_store.connect();
      m_inbox = m_store.getFolder("INBOX");
      m_inbox.open(Folder.READ_WRITE);

      // Set properties
      m_storeProtocol = store;
      m_storeHost = storeHost;
      m_transportProtocol = transport;
      m_transportHost = transportHost;
      m_user = user;
      m_loggedIn = true;
    }
    finally {

      // If there is some failure make sure that everything
      // is closed down properly
      if (!m_loggedIn) {
        if (m_store != null) {
          m_store.close();
          m_store = null;
        }
      }
    }
  }

  /**
   * Returns the name of the given type of protocol
   * @return An array of names
   */
  protected String[] getProtocolNames(Provider.Type type) {
    // Use a vector to temporarily store the provider objects
    java.util.Vector v = new java.util.Vector();

    // Get a list of all of the current providers
    Provider p[] = m_session.getProviders();

    if (p != null) {
      for (int i = 0; i < p.length; i++) {

        // Only get the types requested
        if (p[i].getType() == type) {

          // Store it in our vector
          v.addElement(p[i]);
        }
      }
    }

    // Now create an array of names from the providers that
    // we put in our vector
    String s[] = new String[v.size()];
    for (int i = 0; i < v.size(); i++) {
      Provider prov = (Provider) v.elementAt(i);
      s[i] = prov.getProtocol();
    }
    return s;
  }

  /**
   * Called when this object is bound into a session.
   * @param event The event
   */
  public void valueBound(HttpSessionBindingEvent event) {
    // Nothing to do when the value is bound
  }

  /**
   * Called when this object is unbound from a session
   * @param event The event
   */
  public void valueUnbound(HttpSessionBindingEvent event) {
    // Close the store if necessary
    close();
  }

  /**
   * Close all connections
   */
  public void close() {
    m_loggedIn = false;

    // Close the inbox and store if necessary
    try {
      if (m_inbox != null) {
        // Close without expunging deleted messages
        m_inbox.close(true);
      }
      if (m_store != null) {
        m_store.close();
      }
    }
    catch (MessagingException ex) {
      // Ignore errors on close
    }
    m_inbox = null;
    m_store = null;
  }

}