ch5_e5_13d.java

各种关于JAVA的初级编程

import java.applet.*;
import java.awt.*; 
import java.awt.event.*;

public class ch5_e5_13d extends Applet implements ItemListener
{
    ComplexInputPanel firstInputComplexPnl,sndInputComplexPnl;
    ComplexOutputPanel outputComplexPnl;
    Choice operators;
        
    public ch5_e5_13d()
    {        
        super();
        
        //初始化
        firstInputComplexPnl = new ComplexInputPanel();
        sndInputComplexPnl = new ComplexInputPanel();
        outputComplexPnl = new ComplexOutputPanel();
        
        operators = new Choice();
        operators.add(" ");
        operators.add("+");
        operators.add("-");
        operators.add("*");
        operators.add("/");
        operators.addItemListener(this);
        
        //加入各图形界面成分
        add(firstInputComplexPnl);
        add(operators);
        add(sndInputComplexPnl);
        add(new Label("="));
        add(outputComplexPnl);
    }
    
    public void init()
    {        
        firstInputComplexPnl.resetFaces();
        sndInputComplexPnl.resetFaces();
        outputComplexPnl.resetFaces();
    }//init
    
    public void itemStateChanged(ItemEvent e)
    {
        Choice temp;
        
        try
        {
            if(e.getItemSelectable() instanceof Choice)
            {
                temp = (Choice)(e.getItemSelectable());
                switch(temp.getSelectedItem().charAt(0))
                {
                    case '+':
                        firstInputComplexPnl.getComplexNumber();
                        outputComplexPnl.setComplexNumber(
                            firstInputComplexPnl.complexAdd(
                            sndInputComplexPnl.getComplexNumber()));
                        break;
                    case '-':
                        firstInputComplexPnl.getComplexNumber();
                        outputComplexPnl.setComplexNumber(
                            firstInputComplexPnl.complexMinus(
                            sndInputComplexPnl.getComplexNumber()));
                        break;
                    case '*':
                        firstInputComplexPnl.getComplexNumber();
                        outputComplexPnl.setComplexNumber(
                            firstInputComplexPnl.complexMulti(
                            sndInputComplexPnl.getComplexNumber()));
                        break;
                    case '/':
                        firstInputComplexPnl.getComplexNumber();
                        outputComplexPnl.setComplexNumber(
                            firstInputComplexPnl.complexDivide(
                            sndInputComplexPnl.getComplexNumber()));
                        break;
                    default:
                }
            }
            else
            {
                showStatus("未定义这种事件的处理操作" + e.toString());
                return;
            }
        }
        catch(NumberFormatException nfe)
        {
            showStatus("数据格式错误，请重新输入。");
            firstInputComplexPnl.resetFaces();
            sndInputComplexPnl.resetFaces();
            outputComplexPnl.resetFaces();
        }
    }
    
}

interface ComplexCaculationsInterface
{
    public ComplexNumber complexAdd(ComplexNumber c);
    public ComplexNumber complexAdd(double d);
    public ComplexNumber complexMinus(ComplexNumber c);
    public ComplexNumber complexMinus(double d);
    public ComplexNumber complexMulti(ComplexNumber c);
    public ComplexNumber complexMulti(double d);
    public ComplexNumber complexDivide(double d);
    public ComplexNumber complexDivide(ComplexNumber c);
}

abstract class ComplexPanel extends Panel implements ComplexCaculationsInterface
{
    ComplexNumber innerComplex;
    Label prefixLabel,midLabel,suffixLabel;
    
    ComplexPanel()
    {
        super();
        innerComplex = new ComplexNumber();
        prefixLabel = new Label("(");
        midLabel = new Label("+");
        suffixLabel = new Label("i)");
        
        createAddFaces();
    }
    
    abstract void createAddFaces();
    
    abstract ComplexNumber getComplexNumber()
        throws NumberFormatException;
    
    abstract void setComplexNumber(ComplexNumber c);
    
    abstract void resetFaces();
    
    public ComplexNumber complexAdd(ComplexNumber c)
    {
        return innerComplex.complexAdd(c);
    }
    
    public ComplexNumber complexAdd(double d)
    {
        return innerComplex.complexAdd(d);
    }
    
    public ComplexNumber complexMinus(ComplexNumber c)
    {
        return innerComplex.complexMinus(c);
    }
    
    public ComplexNumber complexMinus(double d)
    {
        return innerComplex.complexMinus(d);
    }
    
    public ComplexNumber complexMulti(ComplexNumber c)
    {
        return innerComplex.complexMulti(c);
    }
    
    public ComplexNumber complexMulti(double d)
    {
        return innerComplex.complexMulti(d);
    }
    
    public ComplexNumber complexDivide(double d)
    {
        return innerComplex.complexDivide(d);
    }
    
    public ComplexNumber complexDivide(ComplexNumber c)
    {
        return innerComplex.complexDivide(c);
    }
}

class ComplexInputPanel extends ComplexPanel
{
    private TextField realTfd,imaginaryTfd;
    
    void createAddFaces()
    {
        realTfd = new TextField(3);
        imaginaryTfd = new TextField(3);
        
        add(prefixLabel);
        add(realTfd);
        add(midLabel);
        add(imaginaryTfd);
        add(suffixLabel);
    }
    
    ComplexNumber getComplexNumber() throws NumberFormatException
    {
        innerComplex = new ComplexNumber(
            Double.parseDouble(realTfd.getText()),
            Double.parseDouble(
                (imaginaryTfd.getText().equals("")) ? "0" : 
                imaginaryTfd.getText() )
        );
        return innerComplex;
    }
    
    void setComplexNumber(ComplexNumber c)
    {
        double r,i;
        
        r = c.getRealPart();
        i = c.getImaginaryPart();
        
        innerComplex.setRealPart(r);
        innerComplex.setImaginaryPart(i);
        realTfd.setText(Double.toString(r));
        imaginaryTfd.setText(Double.toString(i));
    }
    
    void resetFaces()
    {
        realTfd.setText("");
        imaginaryTfd.setText("");
    }
    
}

class ComplexOutputPanel extends ComplexPanel
{
    private Label realLbl,imaginaryLbl;
    
    void createAddFaces()
    {
        realLbl = new Label("     ");
        imaginaryLbl = new Label("     ");
        
        add(prefixLabel);
        add(realLbl);
        add(midLabel);
        add(imaginaryLbl);
        add(suffixLabel);
    }
    
    ComplexNumber getComplexNumber() throws NumberFormatException
    {
        innerComplex = new ComplexNumber(
            Double.parseDouble(realLbl.getText()),
            Double.parseDouble(
                (imaginaryLbl.getText().equals("")) ? "0" : 
                imaginaryLbl.getText() )
        );
        return innerComplex;
    }
    
    void setComplexNumber(ComplexNumber c)
    {
        double r,i;
        
        r = c.getRealPart();
        i = c.getImaginaryPart();
        
        innerComplex.setRealPart(r);
        innerComplex.setImaginaryPart(i);
        realLbl.setText(Double.toString(r));
        imaginaryLbl.setText(Double.toString(i));
    }
    
    void resetFaces()
    {
        realLbl.setText("     ");
        imaginaryLbl.setText("     ");
    }
    
}

class ComplexNumber implements ComplexCaculationsInterface
{
    //域
    private double m_dRealPart;
    private double m_dImaginPart;
    
    //构造函数
    ComplexNumber()
    {
        m_dRealPart = 0.0;
        m_dImaginPart = 0.0;
    }
    ComplexNumber(double r,double i)
    {
        m_dRealPart = r;
        m_dImaginPart = i;
    }
    ComplexNumber(ComplexNumber c)
    {
        m_dRealPart = c.getRealPart();
        m_dImaginPart = c.getImaginaryPart();
    }
    
    //get,set方法
    double getRealPart()
    {
        return m_dRealPart;
    }
    double getImaginaryPart()
    {
        return m_dImaginPart;
    }
    void setRealPart(double d)
    {
        m_dRealPart = d;
    }
    void setImaginaryPart(double d)
    {
        m_dImaginPart = d;
    }

    //复数的共轭
    ComplexNumber complexConjugate()
    {
        return new ComplexNumber(m_dRealPart,
            -1 * m_dImaginPart);
    }    
    
    //复数运算方法
    public ComplexNumber complexAdd(ComplexNumber c)
    {
        return new ComplexNumber(
            this.m_dRealPart + c.getRealPart(),
            this.m_dImaginPart + c.getImaginaryPart());
    }
    public ComplexNumber complexAdd(double c)
    {
        return new ComplexNumber(
            this.m_dRealPart + c, this.m_dImaginPart);
    }
    public ComplexNumber complexMinus(ComplexNumber c)
    {
        return new ComplexNumber(
            this.m_dRealPart - c.getRealPart(),
            this.m_dImaginPart - c.getImaginaryPart());
    }
    public ComplexNumber complexMinus(double c)
    {
        return new ComplexNumber(
            this.m_dRealPart - c, this.m_dImaginPart);
    }
    public ComplexNumber complexMulti(ComplexNumber c)
    {
        return new ComplexNumber(
            this.m_dRealPart * c.getRealPart() 
                - this.m_dImaginPart * c.getImaginaryPart(),
            this.m_dRealPart * c.getImaginaryPart()
                + this.m_dImaginPart * c.getRealPart());
    }
    public ComplexNumber complexMulti(double c)
    {
        return new ComplexNumber(
            this.m_dRealPart * c, this.m_dImaginPart * c);
    }
    public ComplexNumber complexDivide(double d)
    {
        return new ComplexNumber(this.m_dRealPart / d,
            this.m_dImaginPart /d);
    }
    public ComplexNumber complexDivide(ComplexNumber c)
    {
        double mod = c.getRealPart()*c.getRealPart()
            + c.getImaginaryPart()*c.getImaginaryPart();
        if(mod == 0)
            return new ComplexNumber(0,0);
        else
            return this.complexMulti(
                c.complexConjugate()).complexDivide(mod);
    }
    
    
    //toString()
    public String toString()
    {
        return "(" + m_dRealPart + " + " 
            + m_dImaginPart + " i" + ")";
    }
    
}