question.java

自己写的轮询提问的小程序 新手刚学 多多指教 合乎哈

/*
Server's implementation of the Question class. This contains a vector of DataSets.
Copyright (C) 2005-2006  Igor Partola, Michael J. Krikonis, Clark University

This program is free software; you can redistribute it and/or
modify it under the terms of the GNU General Public License
as published by the Free Software Foundation; either version 2
of the License, or (at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
*/

package SharedClasses;

import java.net.*;
import java.io.*;
import java.util.*;

public class Question {
    private String QuestionName;
    private String Question;
    private String AnswerA;
    private String AnswerB;
    private String AnswerC;
    private String AnswerD;
    private String AnswerE;
    private String AnswerF;
    private int Timeout;
    private int QuestionNumber;
    private int NumOfAnswers = 6;
    private Vector DataSetVector = new Vector();
    
    public Question() {
        
    }
    
    public Question(String q, String a, String b, String c, String d, String e, String f, int t, int n, int na) {
        Question = q;
        
        AnswerA = a;
        AnswerB = b;
        AnswerC = c;
        AnswerD = d;
        AnswerE = e;
        AnswerF = f;
        Timeout = t;
        QuestionNumber = n;
        NumOfAnswers = na;
        QuestionName = "Question " + QuestionNumber;
        
        //newDataSet();
    }
    
    public Question(byte[] bytes) {
        
        /*
         * question name size = 0..3
         * question size = 4..7
         * answer A size = 8..11
         * answer B size = 12..15
         * answer C size = 16..19
         * answer D size = 20..23
         * answer E size = 24..27
         * answer F size = 28..31
         * timeout = 32..35
         * number of answers = 36..39
         * data = 40....
         */
        
        int qns = bytesToInt(bytes, 0);
        int qs = bytesToInt(bytes, 4);
        int as = bytesToInt(bytes, 8);
        int bs = bytesToInt(bytes, 12);
        int cs = bytesToInt(bytes, 16);
        int ds = bytesToInt(bytes, 20);
        int es = bytesToInt(bytes, 24);
        int fs = bytesToInt(bytes, 28);
        int t = bytesToInt(bytes, 32);
        int n = bytesToInt(bytes, 36);

        String qn = new String(bytes, 40, qns);
        String q = new String(bytes, 40 + qns, qs);
        String a = new String(bytes, 40 + qns + qs, as);
        String b = new String(bytes, 40 + qns + qs + as, bs);
        String c = new String(bytes, 40 + qns + qs + as + bs, cs);
        String d = new String(bytes, 40 + qns + qs + as + bs + cs, ds);
        String e = new String(bytes, 40 + qns + qs + as + bs + cs + ds, es);
        String f = new String(bytes, 40 + qns + qs + as + bs + cs + ds + es, fs);
        
        QuestionName = qn;
        Question = q;
        
        AnswerA = a;
        AnswerB = b;
        AnswerC = c;
        AnswerD = d;
        AnswerE = e;
        AnswerF = f;
        Timeout = t;
        NumOfAnswers = n;

    }
    
    public void setQuestion(String s) {
        Question = s;
    }

    public void setAnswerA(String s) {
        AnswerA = s;
    }

    public void setAnswerB(String s) {
        AnswerB = s;
    }

    public void setAnswerC(String s) {
        AnswerC = s;
    }

    public void setAnswerD(String s) {
        AnswerD = s;
    }
    
    public void setAnswerE(String s) {
        AnswerE = s;
    }

    public void setAnswerF(String s) {
        AnswerF = s;
    }

    public void setTimeout(int t) {
        Timeout = t;
    }
    
    public void setQuestionNumber(int n) {
        QuestionNumber = n;
        QuestionName = "Question " + QuestionNumber;
    }
    
    public String getQuestionName() {
        return QuestionName;
    }

    public String getQuestion() {
        return Question;
    }

    public String getAnswerA() {
        return AnswerA;
    }

    public String getAnswerB() {
        return AnswerB;
    }

    public String getAnswerC() {
        return AnswerC;
    }

    public String getAnswerD() {
        return AnswerD;
    }
    
    public String getAnswerE() {
        return AnswerE;
    }

    public String getAnswerF() {
        return AnswerF;
    }
    
    public int getTimeout() {
        return Timeout;
    }    
    
    public int getQuestionNumber() {
        return QuestionNumber;
    }
    
    public String toString() {
        return QuestionName;
    }
    
    public Vector getDataSetListing() {
        DataSet d;
        int i;
        int size = DataSetVector.size();
        Vector v = new Vector();
        
        for (i = 0; i < size; i++) {
            d = (DataSet) DataSetVector.elementAt(i);
            v.addElement(d.toString());
        }
        
        return v;
    }

    public DataSet getDataSetAt(int index) {
        if (DataSetVector.size() <= 0) return null;
        return (DataSet) DataSetVector.elementAt(index);
    }
    
    public void newDataSet() {
        DataSet ds = new DataSet(DataSetVector.size() + 1);
        DataSetVector.addElement(ds);
    }
    
    public byte[] getBytes() {
        byte[] buf;
        String qn = getQuestionName();
        String q = getQuestion();
        String a = getAnswerA();
        String b = getAnswerB();
        String c = getAnswerC();
        String d = getAnswerD();
        String e = getAnswerE();
        String f = getAnswerF();
        int t = getTimeout();
        int n = getNumOfAnswers();
        String total;
        
        int qns = qn.getBytes().length;
        int qs = q.getBytes().length;
        int as = a.getBytes().length;
        int bs = b.getBytes().length;
        int cs = c.getBytes().length;
        int ds = d.getBytes().length;
        int es = e.getBytes().length;
        int fs = f.getBytes().length;
        
        
        total = qn + q + a + b + c + d + e + f;
        buf = new byte[total.getBytes().length + 4 * 10];

        System.arraycopy(intToBytes(qns), 0, buf, 0, 4);
        System.arraycopy(intToBytes(qs), 0, buf, 4, 4);
        System.arraycopy(intToBytes(as), 0, buf, 8, 4);
        System.arraycopy(intToBytes(bs), 0, buf, 12, 4);
        System.arraycopy(intToBytes(cs), 0, buf, 16, 4);
        System.arraycopy(intToBytes(ds), 0, buf, 20, 4);
        System.arraycopy(intToBytes(es), 0, buf, 24, 4);
        System.arraycopy(intToBytes(fs), 0, buf, 28, 4);
        System.arraycopy(intToBytes(t), 0, buf, 32, 4);
        System.arraycopy(intToBytes(n), 0, buf, 36, 4);
        System.arraycopy(total.getBytes(), 0, buf, 40, total.getBytes().length);
        /*
         * question name size = 0..3
         * question size = 4..7
         * answer A size = 8..11
         * answer B size = 12..15
         * answer C size = 16..19
         * answer D size = 20..23
         * answer E size = 24..27
         * answer F size = 28..31
         * timeout = 32..35
         * number of answers = 36..39
         * data = 40....
         */
        
        
        return buf; 
    }
    
    public void setNumOfAnswers(int i) {
        int j = i;
        if (i < 2) j = 2;
        if (i > 6) j = 6;
        NumOfAnswers = j;
    }
    
    public int getNumOfAnswers() {
        return NumOfAnswers;
    }    
    
    private byte[] intToBytes(int value) {
        byte [] bytes = new byte [4];

        bytes[0] = (byte)(value >> 24);
        bytes[1] = (byte)(value >> 16);
        bytes[2] = (byte)(value >> 8);
        bytes[3] = (byte)(value);
        return bytes;
        
    }
    
    private static int bytesToInt(byte[] b, int offset) {
        int value = 0;
        for (int i = 0; i < 4; i++) {
            int shift = (4 - 1 - i) * 8;
            value += (b[i + offset] & 0x000000FF) << shift;
        }
        return value;
    }
        
}