    001/*
    002 * Licensed to the Apache Software Foundation (ASF) under one or more
    003 * contributor license agreements.  See the NOTICE file distributed with
    004 * this work for additional information regarding copyright ownership.
    005 * The ASF licenses this file to You under the Apache License, Version 2.0
    006 * (the "License"); you may not use this file except in compliance with
    007 * the License.  You may obtain a copy of the License at
    008 *
    009 *      http://www.apache.org/licenses/LICENSE-2.0
    010 *
    011 * Unless required by applicable law or agreed to in writing, software
    012 * distributed under the License is distributed on an "AS IS" BASIS,
    013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    014 * See the License for the specific language governing permissions and
    015 * limitations under the License.
    016 */
    017package org.apache.commons.net.finger;
    018
    019import java.io.BufferedOutputStream;
    020import java.io.BufferedReader;
    021import java.io.DataOutputStream;
    022import java.io.IOException;
    023import java.io.InputStream;
    024import java.io.InputStreamReader;
    025
    026import org.apache.commons.net.SocketClient;
    027import org.apache.commons.net.util.Charsets;
    028
    029/**
    030 * The FingerClient class implements the client side of the Internet Finger Protocol defined in RFC 1288. To finger a host you create a FingerClient instance,
    031 * connect to the host, query the host, and finally disconnect from the host. If the finger service you want to query is on a non-standard port, connect to the
    032 * host at that port. Here's a sample use:
    033 *
    034 * <pre>
    035 * FingerClient finger;
    036 *
    037 * finger = new FingerClient();
    038 *
    039 * try {
    040 *     finger.connect("foo.bar.com");
    041 *     System.out.println(finger.query("foobar", false));
    042 *     finger.disconnect();
    043 * } catch (IOException e) {
    044 *     System.err.println("Error I/O exception: " + e.getMessage());
    045 *     return;
    046 * }
    047 * </pre>
    048 */
    049
    050public class FingerClient extends SocketClient {
    051    /**
    052     * The default FINGER port. Set to 79 according to RFC 1288.
    053     */
    054    public static final int DEFAULT_PORT = 79;
    055
    056    private static final String LONG_FLAG = "/W ";
    057
    058    private final transient char[] buffer = new char[1024];
    059
    060    /**
    061     * The default FingerClient constructor. Initializes the default port to <code> DEFAULT_PORT </code>.
    062     */
    063    public FingerClient() {
    064        setDefaultPort(DEFAULT_PORT);
    065    }
    066
    067    /**
    068     * Fingers the connected host and returns the input stream from the network connection of the finger query. This is equivalent to calling
    069     * getInputStream(longOutput, ""). You must first connect to a finger server before calling this method, and you should disconnect after finishing reading
    070     * the stream.
    071     *
    072     * @param longOutput Set to true if long output is requested, false if not.
    073     * @return The InputStream of the network connection of the finger query. Can be read to obtain finger results.
    074     * @throws IOException If an I/O error during the operation.
    075     */
    076    public InputStream getInputStream(final boolean longOutput) throws IOException {
    077        return getInputStream(longOutput, "");
    078    }
    079
    080    /**
    081     * Fingers a user and returns the input stream from the network connection of the finger query. You must first connect to a finger server before calling
    082     * this method, and you should disconnect after finishing reading the stream.
    083     *
    084     * @param longOutput Set to true if long output is requested, false if not.
    085     * @param user   The name of the user to finger.
    086     * @return The InputStream of the network connection of the finger query. Can be read to obtain finger results.
    087     * @throws IOException If an I/O error during the operation.
    088     */
    089    public InputStream getInputStream(final boolean longOutput, final String user) throws IOException {
    090        return getInputStream(longOutput, user, null);
    091    }
    092
    093    /**
    094     * Fingers a user and returns the input stream from the network connection of the finger query. You must first connect to a finger server before calling
    095     * this method, and you should disconnect after finishing reading the stream.
    096     *
    097     * @param longOutput Set to true if long output is requested, false if not.
    098     * @param user   The name of the user to finger.
    099     * @param encoding   the character encoding that should be used for the query, null for the platform's default encoding
    100     * @return The InputStream of the network connection of the finger query. Can be read to obtain finger results.
    101     * @throws IOException If an I/O error during the operation.
    102     */
    103    public InputStream getInputStream(final boolean longOutput, final String user, final String encoding) throws IOException {
    104        final DataOutputStream output;
    105        final StringBuilder buffer = new StringBuilder(64);
    106        if (longOutput) {
    107            buffer.append(LONG_FLAG);
    108        }
    109        buffer.append(user);
    110        buffer.append(SocketClient.NETASCII_EOL);
    111
    112        // Note: Charsets.toCharset() returns the platform default for null input
    113        final byte[] encodedQuery = buffer.toString().getBytes(Charsets.toCharset(encoding).name()); // Java 1.6 can use
    114                                                                                                     // charset directly
    115
    116        output = new DataOutputStream(new BufferedOutputStream(_output_, 1024));
    117        output.write(encodedQuery, 0, encodedQuery.length);
    118        output.flush();
    119
    120        return _input_;
    121    }
    122
    123    /**
    124     * Fingers the connected host and returns the output as a String. You must first connect to a finger server before calling this method, and you should
    125     * disconnect afterward. This is equivalent to calling <code> query(longOutput, "") </code>.
    126     *
    127     * @param longOutput Set to true if long output is requested, false if not.
    128     * @return The result of the finger query.
    129     * @throws IOException If an I/O error occurs while reading the socket.
    130     */
    131    public String query(final boolean longOutput) throws IOException {
    132        return query(longOutput, "");
    133    }
    134
    135    /**
    136     * Fingers a user at the connected host and returns the output as a String. You must first connect to a finger server before calling this method, and you
    137     * should disconnect afterward.
    138     *
    139     * @param longOutput Set to true if long output is requested, false if not.
    140     * @param user   The name of the user to finger.
    141     * @return The result of the finger query.
    142     * @throws IOException If an I/O error occurs while reading the socket.
    143     */
    144    public String query(final boolean longOutput, final String user) throws IOException {
    145        int read;
    146        final StringBuilder result = new StringBuilder(buffer.length);
    147
    148        try (final BufferedReader input = new BufferedReader(new InputStreamReader(getInputStream(longOutput, user), getCharset()))) {
    149            while (true) {
    150                read = input.read(buffer, 0, buffer.length);
    151                if (read <= 0) {
    152                    break;
    153                }
    154                result.append(buffer, 0, read);
    155            }
    156        }
    157
    158        return result.toString();
    159    }
    160
    161}