复利计算器4.0-应用版含测试代码

　　该程序复利计算（定额投资），单利计算，本金计算，利率计算，年限计算，银行贷款月还款额计算六项功能，并对空字符和错误字符做出了处理，并加以提醒，也对计算公式进行了测试，目前来说一切正常，如果有读者看出有什么问题，可以提醒一下我，我会及时做出修改。

package com.fulijisuanqi.swing;

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;


public class calcutor extends JFrame{

    public static void main(String[] args) {
        // TODO Auto-generated method stub
        calcutor frame = new calcutor();
        frame.setVisible(true);
        frame.setBounds(100, 100, 400, 400);
        frame.setTitle("计算器3.1");
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    }

    private JPanel jpanel;
    private JLabel label,label00,label01,label02,label03,label04,label05;
    private JComboBox<Object> box;
    private JTextField field01,field02,field03,field04,field05;
    private JButton button;
    private static double benjin,lilv,nianxian,zhongzhi,dingtou,huankuan,daikuan;
    private int index = 0;
    
    public calcutor(){
        
        jpanel = new JPanel();
        jpanel.setBounds(0, 0, 400, 400);
        jpanel.setLayout(null);
        add(jpanel);
        
        label = new JLabel("计算类型：");
        label.setFont(new Font(null, Font.BOLD, 15));
        label.setBounds(10, 10, 80, 30);
        jpanel.add(label);
        
        label00 = new JLabel("@113wangzekai");
        label00.setFont(new Font(null, Font.BOLD, 15));
        label00.setBounds(260, 320, 200, 30);
        jpanel.add(label00);
        
        label01 = new JLabel("本金：");
        label01.setFont(new Font(null, Font.BOLD, 15));
        label01.setBounds(30, 80, 80, 30);
        jpanel.add(label01);
        
        label02 = new JLabel("年利率%：");
        label02.setFont(new Font(null, Font.BOLD, 15));
        label02.setBounds(30, 130, 80, 30);
        jpanel.add(label02);
        
        label03 = new JLabel("年限：");
        label03.setFont(new Font(null, Font.BOLD, 15));
        label03.setBounds(30, 180, 80, 30);
        jpanel.add(label03);
        
        label04 = new JLabel("定投金额：");
        label04.setFont(new Font(null, Font.BOLD, 15));
        label04.setBounds(30, 230, 80, 30);
        jpanel.add(label04);
        
        label05 = new JLabel("终值：");
        label05.setFont(new Font(null, Font.BOLD, 15));
        label05.setBounds(30, 280, 80, 30);
        jpanel.add(label05);
        
        
        //文本框
        field01 = new JTextField();
        field01.setBounds(120, 80, 150, 30);
        jpanel.add(field01);
        
        field02 = new JTextField();
        field02.setBounds(120, 130, 150, 30);
        jpanel.add(field02);
        
        field03 = new JTextField();
        field03.setBounds(120, 180, 150, 30);
        jpanel.add(field03);
        
        field04 = new JTextField();
        field04.setBounds(120, 230, 150, 30);
        jpanel.add(field04);
        
        field05 = new JTextField();
        field05.setBounds(120, 280, 150, 30);
        jpanel.add(field05);
        
        
        //初始化文本框
        field05.setText("计算所得");
        field05.setEnabled(false);
        
        //计算按钮
        button = new JButton("计算");
        button.setBounds(250, 10, 80, 30);
        button.setFont(new Font(null, Font.BOLD, 15));
        jpanel.add(button);
        //按钮监听
        button.addMouseListener(new MouseAdapter() {
            public void mouseClicked(MouseEvent e){
                if(index == 0){
                    zhongzhi = fulicalcutor();
                    field05.setText(Double.toString(zhongzhi));
                    field05.setEnabled(true);
                }else if(index == 1){
                    zhongzhi = danlicalcutor();
                    field04.setText(Double.toString(zhongzhi));
                    field04.setEnabled(true);
                }else if(index == 2){
                    benjin = benjincalcutor();
                    field01.setText(Double.toString(benjin));
                    field01.setEnabled(true);
                }else if(index == 3){
                    lilv = lilvcalcutor();
                    field02.setText(Double.toString(lilv));
                    field02.setEnabled(true);    
                }else if(index == 4){
                    nianxian = nianxiancalcutor();
                    field03.setText(Double.toString(nianxian));
                    field03.setEnabled(true);    
                }else if(index == 5){
                    huankuan = yuehuankuanejisuan();
                    field04.setText(Double.toString(huankuan));
                    field04.setEnabled(true);    
                }
            }
        });
        
        //下拉菜单
        box = new JComboBox<>();
        box.setFont(new Font(null, Font.BOLD, 15));
        box.setModel(new DefaultComboBoxModel<Object>(new Object[]{"复利计算","单利计算","本金计算","利率计算","年限计算","月还款额计算"}));
        box.setBounds(90, 10, 130, 30);
        jpanel.add(box);
        box.addItemListener(new ItemListener() {
            @Override
            public void itemStateChanged(ItemEvent e) {
                if(box.getSelectedIndex()==0){
                    index = 0;
                    change01();
                    clear();
                    field05.setText("计算所得");
                    field05.setEnabled(false);
                    //System.out.println("复利计算");
                }else if(box.getSelectedIndex()==1){
                    index = 1;
                    change();
                    clear();
                    field04.setText("计算所得");
                    field04.setEnabled(false);
                    //System.out.println("单利计算");
                }else if(box.getSelectedIndex()==2){
                    index = 2;
                    change();
                    clear();
                    field01.setText("计算所得");
                    field01.setEnabled(false);
                    //System.out.println("本金计算");
                }else if(box.getSelectedIndex()==3){
                    index = 3;
                    change();
                    clear();
                    field02.setText("计算所得");
                    field02.setEnabled(false);
                    //System.out.println("利率计算");
                }else if(box.getSelectedIndex()==4){
                    index = 4;
                    change();
                    clear();
                    field03.setText("计算所得");
                    field03.setEnabled(false);
                }else if(box.getSelectedIndex()==5){
                    index = 5;
                    change02();
                    clear();
                    field04.setText("计算所得");
                    field04.setEnabled(false);
                }
            }


        });
    }

    //清除数据
    private void clear() {
        field01.setText(null);
        field02.setText(null);
        field03.setText(null);
        field04.setText(null);
        field05.setText(null);
        field01.setEnabled(true);
        field02.setEnabled(true);
        field03.setEnabled(true);
        field04.setEnabled(true);
        field05.setEnabled(true);
    }
    
    //改变内容
    private void change02() {
        label01.setText("贷款金额：");
        label02.setText("年利率%：");
        label03.setText("还款期限：");
        label04.setText("月还款额：");
        label05.setText("");
        field05.setVisible(false);
    }
    private void change01() {
        label01.setText("本金：");
        label02.setText("年利率%：");
        label03.setText("年限：");
        label04.setText("定投金额：");
        label05.setText("终值：");
        field05.setVisible(true);
    }
    private void change() {
        label01.setText("本金：");
        label02.setText("年利率%：");
        label03.setText("年限：");
        label04.setText("终值：");
        label05.setText("");
        field05.setVisible(false);
    }
    
    //月还款额计算
    private double yuehuankuanejisuan() {
        try {
            daikuan = Double.parseDouble(field01.getText());
            lilv = Double.parseDouble(field02.getText());
            nianxian = Double.parseDouble(field03.getText());
        } catch (Exception e) {
            JOptionPane.showMessageDialog(jpanel, "请输入正确的数据");
            //System.out.println("请输入数据");
        }
        return yuehuankuan(daikuan,lilv,nianxian);
    }
    //月还款额的计算公式
    public static double yuehuankuan(double daikuan, double lilv, double nianxian) {
        huankuan = daikuan * (lilv/12) * Math.pow( 1 + lilv/12 ,12 * nianxian)/(Math.pow(1 + lilv/12, 12 * nianxian)-1);
        huankuan = Math.round(huankuan*100)/100;
        return huankuan;
    }
    
    //年限计算
    private double nianxiancalcutor() {
        try {
            zhongzhi = Double.parseDouble(field04.getText());
            lilv = Double.parseDouble(field02.getText());
            benjin = Double.parseDouble(field01.getText());
        } catch (Exception e) {
            JOptionPane.showMessageDialog(jpanel, "请输入正确的数据");
            //System.out.println("请输入数据");
        }
        return nianxian(zhongzhi,lilv,benjin); 
    }
    //年限的计算公式
    public static double nianxian(double zhongzhi, double lilv, double benjin) {
        nianxian = (Math.log(zhongzhi / benjin) / Math.log(1 + lilv));
        nianxian = Math.round(nianxian);
        return nianxian;
    }

    //利率计算
    private double lilvcalcutor() {
        try {
            zhongzhi = Double.parseDouble(field04.getText());
            nianxian = Double.parseDouble(field03.getText());
            benjin = Double.parseDouble(field01.getText());
        } catch (Exception e) {
            JOptionPane.showMessageDialog(jpanel, "请输入正确的数据");
            //System.out.println("请输入数据");
        }
        return lilv(zhongzhi,nianxian,benjin); 
    }
    //利率的计算公式
    public static double lilv(double zhongzhi, double nianxian, double benjin) {
        lilv = Math.pow((zhongzhi / benjin), (1.0 / nianxian)) - 1;
        lilv = Math.round(lilv*100)/100.0;
        return lilv;
    }
    
    //本金计算
    private double benjincalcutor() {
        try {
            zhongzhi = Double.parseDouble(field04.getText());
            lilv = Double.parseDouble(field02.getText());
            nianxian = Double.parseDouble(field03.getText());
        } catch (Exception e) {
            JOptionPane.showMessageDialog(jpanel, "请输入正确的数据");
            //System.out.println("请输入数据");
        }
        return benjin(zhongzhi,lilv,nianxian);
    }
    //本金的计算公式
    public static double benjin(double zhongzhi, double lilv, double nianxian) {
        benjin = zhongzhi / (Math.pow(1 + lilv, nianxian));
        benjin = Math.round(benjin*100)/100; 
        return benjin;
    }

    //单利计算
    private double danlicalcutor() {
        try {
            benjin = Double.parseDouble(field01.getText());
            lilv = Double.parseDouble(field02.getText());
            nianxian = Double.parseDouble(field03.getText());
        } catch (Exception e) {
            JOptionPane.showMessageDialog(jpanel, "请输入正确的数据");
            //System.out.println("请输入数据");
        }
        return zhongzhi(benjin,lilv,nianxian);
        
    }
    //单利的计算公式
    public static double zhongzhi(double benjin, double lilv, double nianxian) {
        zhongzhi = benjin * (1 + lilv * nianxian);
        zhongzhi = Math.round(zhongzhi*100)/100; 
        return zhongzhi;
    }

    //复利计算
    private double fulicalcutor() {
        try {
            benjin = Double.parseDouble(field01.getText());
            lilv = Double.parseDouble(field02.getText());
            nianxian = Double.parseDouble(field03.getText());
        } catch (Exception e) {
            JOptionPane.showMessageDialog(jpanel, "请输入正确的数据");
            //System.out.println("请输入数据");
        }
        try {
            dingtou = Double.parseDouble(field04.getText());
        } catch (NumberFormatException e2) {
            dingtou = 0;
        }
        return zhongzhi(benjin,lilv,nianxian,dingtou);
    }
    //复利的计算公式
    public static double zhongzhi(double benjin, double lilv, double nianxian,
            double dingtou) {
        for(int i = 0;i < nianxian;i++){
            benjin = benjin * (1 + lilv);
            benjin = benjin + dingtou;
        }
        zhongzhi = benjin - dingtou;
        zhongzhi = Math.round(zhongzhi*100)/100;
        return zhongzhi;
    }

}

程序运行结果如下：

测试代码如下：

package com.fulijisuanqi.Test;

import static org.junit.Assert.*;
import static org.hamcrest.CoreMatchers.*;
import org.junit.Test;
import com.fulijisuanqi.swing.calcutor;

public class calculatorTest {

    
    @Test
    public void testYuehuankuan() {
        calcutor cutor = new calcutor();
        double str1 = cutor.yuehuankuan(100000, 0.05, 10);
        assertThat(str1, is(1060.0));
    }

    @Test
    public void testNianxian() {
        calcutor cutor = new calcutor();
        double str2 = cutor.nianxian(220000, 0.03, 100000);
        assertThat(str2, is(27.0));
    }

    @Test
    public void testLilv() {
        calcutor cutor = new calcutor();
        double str2 = cutor.lilv(200000, 30, 100000);
        assertThat(str2, is(0.02));
    }

    @Test
    public void testBenjin() {
        calcutor cutor = new calcutor();
        double str2 = cutor.benjin(3000000, 0.05, 20);
        assertThat(str2, is(1130668.0));
    }

    @Test
    public void testZhongzhiDoubleDoubleDouble() {
        calcutor cutor = new calcutor();
        double str2 = cutor.zhongzhi(100000, 0.03, 30);
        assertThat(str2, is(190000.0));
    }

    @Test
    public void testZhongzhiDoubleDoubleDoubleDouble() {
        calcutor cutor = new calcutor();
        double str2 = cutor.zhongzhi(100000, 0.03, 30, 0);
        assertThat(str2, is(242726.0));
    }

}

测试结果如下：