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      1 /*
      2  * Copyright (c) 2011 Oracle and/or its affiliates. All rights reserved.
      3  *
      4  * Redistribution and use in source and binary forms, with or without
      5  * modification, are permitted provided that the following conditions
      6  * are met:
      7  *
      8  *   - Redistributions of source code must retain the above copyright
      9  *     notice, this list of conditions and the following disclaimer.
     10  *
     11  *   - Redistributions in binary form must reproduce the above copyright
     12  *     notice, this list of conditions and the following disclaimer in the
     13  *     documentation and/or other materials provided with the distribution.
     14  *
     15  *   - Neither the name of Oracle nor the names of its
     16  *     contributors may be used to endorse or promote products derived
     17  *     from this software without specific prior written permission.
     18  *
     19  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
     20  * IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
     21  * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     22  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT OWNER OR
     23  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
     24  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
     25  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
     26  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
     27  * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
     28  * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
     29  * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     30  */
     31 
     32 /*
     33  * This source code is provided to illustrate the usage of a given feature
     34  * or technique and has been deliberately simplified. Additional steps
     35  * required for a production-quality application, such as security checks,
     36  * input validation and proper error handling, might not be present in
     37  * this sample code.
     38  */
     39 
     40 
     41 import java.nio.ByteBuffer;
     42 
     43 /**
     44  * The first state a newly connected {@code Client} is in, this
     45  * handles writing out the welcoming message and reads the response
     46  * up to a newline. When a newline character have been received
     47  * it changes the handler from NameReader to MessageReader on the
     48  * client.
     49  */
     50 class NameReader implements DataReader {
     51     private final StringBuilder buffer = new StringBuilder();
     52     private final ChatServer chatServer;
     53     private boolean once = true;
     54     private static final String NEWLINE = "\n";
     55 
     56     public NameReader(ChatServer chatServer) {
     57         this.chatServer = chatServer;
     58     }
     59 
     60     /**
     61      * Writes the welcoming message to the client the first time this method
     62      * is called.
     63      *
     64      * @param client the client to receive the message
     65      */
     66     @Override
     67     public void beforeRead(Client client) {
     68         // if it is a long name that takes more than one read we only want to display Name: once.
     69         if (once) {
     70             client.writeStringMessage("Name: ");
     71             once = false;
     72         }
     73     }
     74 
     75     public boolean acceptsMessages() {
     76         return false;
     77     }
     78 
     79     /**
     80      * Receives incoming data from the socket, searches for a newline
     81      * and tries to set the username if one is found
     82      */
     83     @Override
     84     public void onData(Client client, ByteBuffer buffer, int bytes) {
     85         buffer.flip();
     86         String name;
     87         name = this.buffer.append(new String(buffer.array(), 0, bytes)).toString();
     88         if (name.contains(NEWLINE)) {
     89             onUserNameRead(client, name);
     90         }
     91     }
     92 
     93     /**
     94      * Splits the name on the newlines, takes the first as the username
     95      * and appends everything else to the clients message buffer.
     96      * Sets the clients handler to MessageReader.
     97      *
     98      * @param client the client to set the username for
     99      * @param name the string containing the buffered input
    100      */
    101     private void onUserNameRead(Client client, String name) {
    102         String[] strings = name.split(NEWLINE, 2);
    103         client.setUserName(strings[0].trim());
    104         sendRemainingParts(client, strings);
    105         client.setReader(new ClientReader(chatServer, new MessageReader(chatServer)));
    106         client.writeStringMessage("Welcome " + client.getUserName() + "\n");
    107     }
    108 
    109     /**
    110      * Appends the remaining parts to the clients message buffer
    111      *
    112      * @param client the client
    113      * @param strings the messages to append to the buffer
    114      */
    115     private void sendRemainingParts(Client client, String[] strings) {
    116         for (int i = 1; i < strings.length; ++i) {
    117             client.appendMessage(strings[i]);
    118         }
    119     }
    120 }
    121