Commons Net example source code file (FingerClient.java)

This example Commons Net source code file (FingerClient.java) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Java - Commons Net tags/keywords

bufferedreader, dataoutputstream, fingerclient, inputstream, inputstream, inputstreamreader, io, ioexception, ioexception, socketclient, string, string, stringbuilder, stringbuilder, w

The Commons Net FingerClient.java source code

/*
 * 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 org.apache.commons.net.finger;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.BufferedOutputStream;
import java.io.DataOutputStream;

import org.apache.commons.net.SocketClient;

/***
 * 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, 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 host at that port.
 * Here's a sample use:
 * <pre>
 *    FingerClient finger;
 *
 *    finger = new FingerClient();
 *
 *    try {
 *      finger.connect("foo.bar.com");
 *      System.out.println(finger.query("foobar", false));
 *      finger.disconnect();
 *    } catch(IOException e) {
 *      System.err.println("Error I/O exception: " + e.getMessage());
 *      return;
 *    }
 * </pre>
 * <p>
 * <p>
 ***/

public class FingerClient extends SocketClient
{
    /***
     * The default FINGER port.  Set to 79 according to RFC 1288.
     ***/
    public static final int DEFAULT_PORT = 79;

    private static final String __LONG_FLAG = "/W ";

    private transient char[] __buffer = new char[1024];

    /***
     * The default FingerClient constructor.  Initializes the
     * default port to <code> DEFAULT_PORT .
     ***/
    public FingerClient()
    {
        setDefaultPort(DEFAULT_PORT);
    }


    /***
     * 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 should disconnect afterward.
     * <p>
     * @param longOutput Set to true if long output is requested, false if not.
     * @param username  The name of the user to finger.
     * @return The result of the finger query.
     * @exception IOException If an I/O error occurs while reading the socket.
     ***/
    public String query(boolean longOutput, String username) throws IOException
    {
        int read;
        StringBuilder result = new StringBuilder(__buffer.length);
        BufferedReader input;

        input =
            new BufferedReader(new InputStreamReader(getInputStream(longOutput,
                               username)));

        try {
            while (true)
            {
                read = input.read(__buffer, 0, __buffer.length);
                if (read <= 0)
                    break;
                result.append(__buffer, 0, read);
            }
        } finally {
            input.close();
        }

        return result.toString();
    }


    /***
     * 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 disconnect afterward.
     * This is equivalent to calling <code> query(longOutput, "") .
     * <p>
     * @param longOutput Set to true if long output is requested, false if not.
     * @return The result of the finger query.
     * @exception IOException If an I/O error occurs while reading the socket.
     ***/
    public String query(boolean longOutput) throws IOException
    {
        return query(longOutput, "");
    }


    /***
     * 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 this method, and you should disconnect after finishing reading
     * the stream.
     * <p>
     * @param longOutput Set to true if long output is requested, false if not.
     * @param username  The name of the user to finger.
     * @return The InputStream of the network connection of the finger query.
     *         Can be read to obtain finger results.
     * @exception IOException If an I/O error during the operation.
     ***/
    public InputStream getInputStream(boolean longOutput, String username)
    throws IOException
    {
        return getInputStream(longOutput, username, null);
    }

    /***
     * 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 this method, and you should disconnect after finishing reading
     * the stream.
     * <p>
     * @param longOutput Set to true if long output is requested, false if not.
     * @param username  The name of the user to finger.
     * @param encoding the character encoding that should be used for the query,
     *        null for the platform's default encoding
     * @return The InputStream of the network connection of the finger query.
     *         Can be read to obtain finger results.
     * @exception IOException If an I/O error during the operation.
     ***/
    public InputStream getInputStream(boolean longOutput, String username, String encoding)
    throws IOException
    {
        DataOutputStream output;
        StringBuilder buffer = new StringBuilder(64);
        if (longOutput)
            buffer.append(__LONG_FLAG);
        buffer.append(username);
        buffer.append(SocketClient.NETASCII_EOL);

        byte[] encodedQuery =
                (encoding == null ? buffer.toString().getBytes() : buffer.toString().getBytes(encoding));

        output = new DataOutputStream(new BufferedOutputStream(_output_, 1024));
        output.write(encodedQuery, 0, encodedQuery.length);
        output.flush();

        return _input_;
    }


    /***
     * Fingers the connected host and returns the input stream from
     * the network connection of the finger query.  This is equivalent to
     * calling getInputStream(longOutput, "").  You must first connect to a
     * finger server before calling this method, and you should disconnect
     * after finishing reading the stream.
     * <p>
     * @param longOutput Set to true if long output is requested, false if not.
     * @return The InputStream of the network connection of the finger query.
     *         Can be read to obtain finger results.
     * @exception IOException If an I/O error during the operation.
     ***/
    public InputStream getInputStream(boolean longOutput) throws IOException
    {
        return getInputStream(longOutput, "");
    }

}