Java tutorial
/* * Licensed to the Apache Software Foundation (ASF) under one or more * contributor license agreements. See the NOTICE file distributed with * this work for additional information regarding copyright ownership. * The ASF licenses this file to You under the Apache License, Version 2.0 * (the "License"); you may not use this file except in compliance with * the License. You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ package examples.mail; import java.io.BufferedReader; import java.io.Console; import java.io.IOException; import java.io.InputStreamReader; import java.net.URI; import java.util.Locale; import org.apache.commons.net.ProtocolCommandListener; import org.apache.commons.net.imap.IMAPClient; import org.apache.commons.net.imap.IMAPSClient; /** * Utility class for shared IMAP utilities */ class IMAPUtils { /** * Parse the URI and use the details to connect to the IMAP(S) server and login. * * @param uri the URI to use, e.g. imaps://user:pass@imap.mail.yahoo.com/folder * or imaps://user:pass@imap.googlemail.com/folder * @param defaultTimeout initial timeout (in milliseconds) * @param listener for tracing protocol IO (may be null) * @return the IMAP client - connected and logged in * @throws IOException if any problems occur */ static IMAPClient imapLogin(URI uri, int defaultTimeout, ProtocolCommandListener listener) throws IOException { final String userInfo = uri.getUserInfo(); if (userInfo == null) { throw new IllegalArgumentException("Missing userInfo details"); } String[] userpass = userInfo.split(":"); if (userpass.length != 2) { throw new IllegalArgumentException("Invalid userInfo details: '" + userInfo + "'"); } String username = userpass[0]; String password = userpass[1]; /* * If the initial password is: * '*' - replace it with a line read from the system console * '-' - replace it with next line from STDIN * 'ABCD' - if the input is all upper case, use the field as an environment variable name * * Note: there are no guarantees that the password cannot be snooped. * * Even using the console may be subject to memory snooping, * however it should be safer than the other methods. * * STDIN may require creating a temporary file which could be read by others * Environment variables may be visible by using PS */ if ("-".equals(password)) { // stdin BufferedReader in = new BufferedReader(new InputStreamReader(System.in)); password = in.readLine(); } else if ("*".equals(password)) { // console Console con = System.console(); // Java 1.6 if (con != null) { char[] pwd = con.readPassword("Password for " + username + ": "); password = new String(pwd); } else { throw new IOException("Cannot access Console"); } } else if (password.equals(password.toUpperCase(Locale.ROOT))) { // environment variable name final String tmp = System.getenv(password); if (tmp != null) { // don't overwrite if variable does not exist (just in case password is all uppers) password = tmp; } } final IMAPClient imap; final String scheme = uri.getScheme(); if ("imaps".equalsIgnoreCase(scheme)) { System.out.println("Using secure protocol"); imap = new IMAPSClient(true); // implicit } else if ("imap".equalsIgnoreCase(scheme)) { imap = new IMAPClient(); } else { throw new IllegalArgumentException("Invalid protocol: " + scheme); } final int port = uri.getPort(); if (port != -1) { imap.setDefaultPort(port); } imap.setDefaultTimeout(defaultTimeout); if (listener != null) { imap.addProtocolCommandListener(listener); } final String server = uri.getHost(); System.out.println("Connecting to server " + server + " on " + imap.getDefaultPort()); try { imap.connect(server); System.out.println("Successfully connected"); } catch (IOException e) { throw new RuntimeException("Could not connect to server.", e); } if (!imap.login(username, password)) { imap.disconnect(); throw new RuntimeException("Could not login to server. Check login details."); } return imap; } }