session.java

java Email you can use it to send email to others

     * returns the Provider that appeared first in the 
     * configuration files. If an implementation for the protocol 
     * isn't found, throws NoSuchProviderException
     *
     * @param  protocol  Configured protocol (i.e. smtp, imap, etc)
     * @return Currently configured Provider for the specified protocol
     * @exception	NoSuchProviderException If a provider for the given
     *			protocol is not found.
     */
    public synchronized Provider getProvider(String protocol)
	                                throws NoSuchProviderException {

	if (protocol == null || protocol.length() <= 0) {
	    throw new NoSuchProviderException("Invalid protocol: null");
	}

	Provider _provider = null;

	// check if the mail.<protocol>.class property exists
	String _className = props.getProperty("mail."+protocol+".class");
	if (_className != null) {
	    if (debug) {
		pr("DEBUG: mail."+protocol+
				   ".class property exists and points to " + 
				   _className);
	    }
	    _provider = (Provider)providersByClassName.get(_className);
	} 

	if (_provider != null) {
	    return _provider;
	} else {
	    // returning currently default protocol in providersByProtocol
	    _provider = (Provider)providersByProtocol.get(protocol);
	}

	if (_provider == null) {
	    throw new NoSuchProviderException("No provider for " + protocol);
	} else {
	    if (debug) {
		pr("DEBUG: getProvider() returning " + 
				   _provider.toString());
	    }
	    return _provider;
	}
    }

    /**
     * Set the passed Provider to be the default implementation
     * for the protocol in Provider.protocol overriding any previous values.
     *
     * @param provider Currently configured Provider which will be 
     * set as the default for the protocol
     * @exception	NoSuchProviderException If the provider passed in
     *			is invalid.
     */
    public synchronized void setProvider(Provider provider)
				throws NoSuchProviderException {
	if (provider == null) {
	    throw new NoSuchProviderException("Can't set null provider");
	}
	providersByProtocol.put(provider.getProtocol(), provider);
	props.put("mail." + provider.getProtocol() + ".class", 
		  provider.getClassName());
    }


    /**
     * Get a Store object that implements this user's desired Store
     * protocol. The <code>mail.store.protocol</code> property specifies the
     * desired protocol. If an appropriate Store object is not obtained, 
     * NoSuchProviderException is thrown
     *
     * @return 		a Store object 
     * @exception	NoSuchProviderException If a provider for the given
     *			protocol is not found.
     */
    public Store getStore() throws NoSuchProviderException {
	return getStore(getProperty("mail.store.protocol"));
    }

    /**
     * Get a Store object that implements the specified protocol. If an
     * appropriate Store object cannot be obtained, 
     * NoSuchProviderException is thrown.
     *
     * @param	        protocol
     * @return		a Store object 
     * @exception	NoSuchProviderException If a provider for the given
     *			protocol is not found.
     */
    public Store getStore(String protocol) throws NoSuchProviderException {
	return getStore(new URLName(protocol, null, -1, null, null, null));
    }


    /**
     * Get a Store object for the given URLName. If the requested Store
     * object cannot be obtained, NoSuchProviderException is thrown.
     *
     * The "scheme" part of the URL string (Refer RFC 1738) is used 
     * to locate the Store protocol. <p>
     *
     * @param	url	URLName that represents the desired Store
     * @return		a closed Store object
     * @see		#getFolder(URLName)
     * @see		javax.mail.URLName
     * @exception	NoSuchProviderException If a provider for the given
     *			URLName is not found.
     */
    public Store getStore(URLName url) throws NoSuchProviderException {
	String protocol = url.getProtocol();
	Provider p = getProvider(protocol);
	return getStore(p, url);
    }

    /**
     * Get an instance of the store specified by Provider. Instantiates
     * the store and returns it.
     * 
     * @param provider Store Provider that will be instantiated
     * @return Instantiated Store
     * @exception	NoSuchProviderException If a provider for the given
     *			Provider is not found.
     */
    public Store getStore(Provider provider) throws NoSuchProviderException {
	return getStore(provider, null);
    }


    /**
     * Get an instance of the store specified by Provider. If the URLName
     * is not null, uses it, otherwise creates a new one. Instantiates
     * the store and returns it. This is a private method used by
     * getStore(Provider) and getStore(URLName)
     * 
     * @param provider Store Provider that will be instantiated
     * @param url      URLName used to instantiate the Store
     * @return Instantiated Store
     * @exception	NoSuchProviderException If a provider for the given
     *			Provider/URLName is not found.
     */
    private Store getStore(Provider provider, URLName url) 
	throws NoSuchProviderException {

	// make sure we have the correct type of provider
	if (provider == null || provider.getType() != Provider.Type.STORE ) {
	    throw new NoSuchProviderException("invalid provider");
	}
		
	try {
	    return (Store) getService(provider, url);
	} catch (ClassCastException cce) {
	    throw new NoSuchProviderException("incorrect class");
	}
    }

    /**
     * Get a closed Folder object for the given URLName. If the requested
     * Folder object cannot be obtained, null is returned. <p>
     *
     * The "scheme" part of the URL string (Refer RFC 1738) is used
     * to locate the Store protocol. The rest of the URL string (that is,
     * the "schemepart", as per RFC 1738) is used by that Store
     * in a protocol dependent manner to locate and instantiate the
     * appropriate Folder object. <p>
     *
     * Note that RFC 1738 also specifies the syntax for the 
     * "schemepart" for IP-based protocols (IMAP4, POP3, etc.).
     * Providers of IP-based mail Stores should implement that
     * syntax for referring to Folders. <p>
     *
     * @param	url	URLName that represents the desired folder
     * @return		Folder
     * @see		#getStore(URLName)
     * @see		javax.mail.URLName
     * @exception	NoSuchProviderException If a provider for the given
     *			URLName is not found.
     * @exception	MessagingException if the Folder could not be 
     *			located or created.
     */
    public Folder getFolder(URLName url)
		throws MessagingException {
	// First get the Store
	Store store = getStore(url);
	store.connect();
	return store.getFolder(url);
    }

    /**
     * Get a Transport object that implements this user's desired 
     * Transport protcol. The <code>mail.transport.protocol</code> property 
     * specifies the desired protocol. If an appropriate Transport 
     * object cannot be obtained, MessagingException is thrown.
     *
     * @return 		a Transport object 
     * @exception	NoSuchProviderException If the provider is not found.
     */
    public Transport getTransport() throws NoSuchProviderException {
        return getTransport(getProperty("mail.transport.protocol"));
    }

    /**
     * Get a Transport object that implements the specified protocol.
     * If an appropriate Transport object cannot be obtained, null is
     * returned.
     *
     * @return 		a Transport object 
     * @exception	NoSuchProviderException If provider for the given
     *			protocol is not found.
     */
    public Transport getTransport(String protocol)
				throws NoSuchProviderException {
	return getTransport(new URLName(protocol, null, -1, null, null, null));
    }


    /**
     * Get a Transport object for the given URLName. If the requested 
     * Transport object cannot be obtained, NoSuchProviderException is thrown.
     *
     * The "scheme" part of the URL string (Refer RFC 1738) is used 
     * to locate the Transport protocol. <p>
     *
     * @param	url	URLName that represents the desired Transport
     * @return		a closed Transport object
     * @see		javax.mail.URLName
     * @exception	NoSuchProviderException If a provider for the given
     *			URLName is not found.
     */
    public Transport getTransport(URLName url) throws NoSuchProviderException {
	String protocol = url.getProtocol();
	Provider p = getProvider(protocol);
	return getTransport(p, url);
    }

    /**
     * Get an instance of the transport specified in the Provider. Instantiates
     * the transport and returns it.
     * 
     * @param provider Transport Provider that will be instantiated
     * @return Instantiated Transport
     * @exception	NoSuchProviderException If provider for the given
     *			provider is not found.
     */
    public Transport getTransport(Provider provider) 
	                                     throws NoSuchProviderException {
	return getTransport(provider, null);
    }

    /**
     * Get a Transport object that can transport a Message to the
     * specified address type.
     *
     * @param	address
     * @return	A Transport object
     * @see javax.mail.Address
     * @exception	NoSuchProviderException If provider for the 
     *			Address type is not found
     */
    public Transport getTransport(Address address) 
	                                     throws NoSuchProviderException {

	String transportProtocol = (String)addressMap.get(address.getType());
	if (transportProtocol == null) {
	    throw new NoSuchProviderException("No provider for Address type: "+
					      address.getType());
	} else {
	    return getTransport(transportProtocol);
	}
    }

    /**
     * Get a Transport object using the given provider and urlname.
     *
     * @param	provider	the provider to use
     * @param	url		urlname to use (can be null)
     * @return A Transport object
     * @exception	NoSuchProviderException	If no provider or the provider
     *			was the wrong class.	
     */

    private Transport getTransport(Provider provider, URLName url)
					throws NoSuchProviderException {
	// make sure we have the correct type of provider
	if (provider == null || provider.getType() != Provider.Type.TRANSPORT) {
	    throw new NoSuchProviderException("invalid provider");
	}

	try {
	    return (Transport) getService(provider, url);
	} catch (ClassCastException cce) {
	    throw new NoSuchProviderException("incorrect class");
	}
    }

    /**
     * Get a Service object.  Needs a provider object, but will
     * create a URLName if needed.  It attempts to instantiate
     * the correct class.
     *
     * @param provider	which provider to use
     * @param url	which URLName to use (can be null)
     * @exception	NoSuchProviderException	thrown when the class cannot be
     *			found or when it does not have the correct constructor
     *			(Session, URLName), or if it is not derived from
     *			Service.
     */
    private Object getService(Provider provider, URLName url)
					throws NoSuchProviderException {
	// need a provider and url
	if (provider == null) {
	    throw new NoSuchProviderException("null");
	}

	// create a url if needed
	if (url == null) {
	    url = new URLName(provider.getProtocol(), null, -1, 
			      null, null, null);
	}

	Object service = null;
	
	// get the ClassLoader associated with the Authenticator
	ClassLoader cl;
	if (authenticator != null)
	    cl = authenticator.getClass().getClassLoader();
	else
	    cl = this.getClass().getClassLoader();

	// now load the class
	Class serviceClass = null;
	try {
	    // First try the "application's" class loader.
	    ClassLoader ccl = getContextClassLoader();
	    if (ccl != null)
		try {
		    serviceClass = ccl.loadClass(provider.getClassName());
		} catch (ClassNotFoundException ex) {
		    // ignore it
		}
	    if (serviceClass == null)
		serviceClass = cl.loadClass(provider.getClassName());
	} catch (Exception ex1) {
	    // That didn't work, now try the "system" class loader.
	    // (Need both of these because JDK 1.1 class loaders
	    // may not delegate to their parent class loader.)
	    try {
		serviceClass = Class.forName(provider.getClassName());
	    } catch (Exception ex) {
		// Nothing worked, give up.
		if (debug) ex.printStackTrace(getDebugOut());
		throw new NoSuchProviderException(provider.getProtocol());
	    }
	}

	// construct an instance of the class
	try {
	    Class[] c = {javax.mail.Session.class, javax.mail.URLName.class};
	    Constructor cons = serviceClass.getConstructor(c);

	    Object[] o = {this, url};
	    service = cons.newInstance(o);

	} catch (Exception ex) {
	    if (debug) ex.printStackTrace(getDebugOut());
	    throw new NoSuchProviderException(provider.getProtocol());
	}

	return service;
    }

    /**
     * Save a PasswordAuthentication for this (store or transport) URLName.
     * If pw is null the entry corresponding to the URLName is removed.
     * <p>
     * This is normally used only by the store or transport implementations
     * to allow authentication information to be shared among multiple
     * uses of a session.
     */
    public void setPasswordAuthentication(URLName url,
					  PasswordAuthentication pw) {
	if (pw == null)
	    authTable.remove(url);
	else
	    authTable.put(url, pw);
    }

    /**
     * Return any saved PasswordAuthentication for this (store or transport)
     * URLName.  Normally used only by store or transport implementations.
     *
     * @return	the PasswordAuthentication corresponding to the URLName
     */
    public PasswordAuthentication getPasswordAuthentication(URLName url) {
	return (PasswordAuthentication)authTable.get(url);
    }

    /**
     * Call back to the application to get the needed user name and password.
     * The application should put up a dialog something like:
     * <p> <pre>
     * Connecting to &lt;protocol&gt; mail service on host &lt;addr&gt;, port &lt;port&gt;.
     * &lt;prompt&gt;
     *
     * User Name: &lt;defaultUserName&gt;
     * Password:
     * </pre>
     *
     * @param	addr		InetAddress of the host.  may be null.
     * @param	protocol	protocol scheme (e.g. imap, pop3, etc.)
     * @param	prompt		any additional String to show as part of
     *                          the prompt; may be null.
     * @param	defaultUserName	the default username. may be null.
     * @return	the authentication which was collected by the authenticator; 
     *          may be null.
     */
    public PasswordAuthentication requestPasswordAuthentication(
	InetAddress addr, int port,
	String protocol, String prompt, String defaultUserName) {

	if (authenticator != null) {
	    return authenticator.requestPasswordAuthentication(
		addr, port, protocol, prompt, defaultUserName);
	} else {
	    return null;
	}