结队2.0

package com.zhadan.Frame;

import java.awt.event.MouseAdapter;

//VS4E -- DO NOT REMOVE THIS LINE!
public class MainFrame extends JFrame {

    private static final long serialVersionUID = 1L;
    private JLabel jLabel0;
    private JTextField jTextField0;
    private JLabel jLabel1;
    private JTextField jTextField1;
    private JTextField jTextField2;
    private JTextField jTextField3;
    private JLabel jLabel3;
    private JLabel jLabel2;
    private JButton jButton0;
    public MainFrame() {
        initComponents();
    }

    private void initComponents() {
        setLayout(new GroupLayout());
        add(getJLabel0(), new Constraints(new Leading(22, 32, 10, 10), new Leading(36, 24, 12, 12)));
        add(getJTextField0(), new Constraints(new Leading(66, 219, 10, 10), new Leading(37, 23, 12, 12)));
        add(getJLabel1(), new Constraints(new Leading(22, 28, 12, 12), new Leading(78, 23, 12, 12)));
        add(getJTextField1(), new Constraints(new Leading(66, 218, 12, 12), new Leading(78, 12, 12)));
        add(getJTextField2(), new Constraints(new Leading(66, 218, 12, 12), new Leading(121, 12, 12)));
        add(getJLabel3(), new Constraints(new Leading(22, 12, 12), new Leading(161, 22, 12, 12)));
        add(getJLabel2(), new Constraints(new Leading(22, 12, 12), new Leading(121, 22, 12, 12)));
        add(getJComboBox0(), new Constraints(new Leading(109, 10, 10), new Leading(202, 12, 12)));
        add(getJLabel4(), new Constraints(new Leading(89, 10, 10), new Leading(179, -8, 10, 10)));
        add(getJButton0(), new Constraints(new Leading(17, 10, 10), new Leading(202, 12, 12)));
        add(getJTextField3(), new Constraints(new Leading(66, 218, 12, 12), new Leading(157, 23, 10, 10)));
        add(getJLabel5(), new Constraints(new Leading(56, 10, 10), new Leading(265, 10, 10)));
        add(getJLabel6(), new Constraints(new Leading(137, 12, 12), new Leading(12, 12, 12)));
        setSize(321, 314);
    }

    private JLabel getJLabel6() {
        if (jLabel6 == null) {
            jLabel6 = new JLabel();
            jLabel6.setText("复利计算");
        }
        return jLabel6;
    }

    private JLabel getJLabel5() {
        if (jLabel5 == null) {
            jLabel5 = new JLabel();
            jLabel5.setText("备注：要求什么哪里就不要你填");
        }
        return jLabel5;
    }

    private JLabel getJLabel4() {
        if (jLabel4 == null) {
            jLabel4 = new JLabel();
            jLabel4.setText("要求什么就在哪里就不用写");
        }
        return jLabel4;
    }

    private JComboBox getJComboBox0() {
        if (jComboBox0 == null) {
            jComboBox0 = new JComboBox();
            jComboBox0.setModel(new DefaultComboBoxModel(new Object[] { "复利计算", "求本金", "求利息", "求年限" }));
            jComboBox0.setDoubleBuffered(false);
            jComboBox0.setBorder(null);
        }
        return jComboBox0;
    }

    private JButton getJButton0() {
        if (jButton0 == null) {
            jButton0 = new JButton();
            jButton0.setText("计算");
            jButton0.addMouseListener(new MouseAdapter() {
    
                public void mouseClicked(MouseEvent event) {
                    jButton0MouseMouseClicked(event);
                }
            });
        }
        return jButton0;
    }

    private JLabel getJLabel2() {
        if (jLabel2 == null) {
            jLabel2 = new JLabel();
            jLabel2.setText("年限");
        }
        return jLabel2;
    }

    private JLabel getJLabel3() {
        if (jLabel3 == null) {
            jLabel3 = new JLabel();
            jLabel3.setText("总额");
        }
        return jLabel3;
    }

    private JTextField getJTextField3() {
        if (jTextField3 == null) {
            jTextField3 = new JTextField();
        }
        return jTextField3;
    }

    private JTextField getJTextField2() {
        if (jTextField2 == null) {
            jTextField2 = new JTextField();
        }
        return jTextField2;
    }

    private JTextField getJTextField1() {
        if (jTextField1 == null) {
            jTextField1 = new JTextField();
        }
        return jTextField1;
    }

    private JLabel getJLabel1() {
        if (jLabel1 == null) {
            jLabel1 = new JLabel();
            jLabel1.setText("利息");
        }
        return jLabel1;
    }

    private JTextField getJTextField0() {
        if (jTextField0 == null) {
            jTextField0 = new JTextField();
        }
        return jTextField0;
    }

    private JLabel getJLabel0() {
        if (jLabel0 == null) {
            jLabel0 = new JLabel();
            jLabel0.setText("本金");
        }
        return jLabel0;
    }

    private static void installLnF() {
        try {
            String lnfClassname = PREFERRED_LOOK_AND_FEEL;
            if (lnfClassname == null)
                lnfClassname = UIManager.getCrossPlatformLookAndFeelClassName();
            UIManager.setLookAndFeel(lnfClassname);
        } catch (Exception e) {
            System.err.println("Cannot install " + PREFERRED_LOOK_AND_FEEL + " on this platform:" + e.getMessage());
        }
    }

    /**
    * Main entry of the class.
    * Note: This class is only created so that you can easily preview the result at runtime.
    * It is not expected to be managed by the designer.
    * You can modify it as you like.
    */
    public static void main(String[] args) {
        installLnF();
        SwingUtilities.invokeLater(new Runnable() {
            public void run() {
                MainFrame frame = new MainFrame();
                frame.setDefaultCloseOperation(MainFrame.EXIT_ON_CLOSE);
                frame.setTitle("MainFrame");
                frame.getContentPane().setPreferredSize(frame.getSize());
                frame.pack();
                frame.setLocationRelativeTo(null);
                frame.setVisible(true);
            }
        });
    }
    Fuli f =new Fuli();
    Benjin b =new Benjin();
    Lilv l = new Lilv();
    Nianxian n = new Nianxian();
    private JComboBox jComboBox0;
    private JLabel jLabel4;
    private JLabel jLabel5;
    private JLabel jLabel6;
    private static final String PREFERRED_LOOK_AND_FEEL = "javax.swing.plaf.metal.MetalLookAndFeel";
    private void jButton0MouseMouseClicked(MouseEvent event) {
        String p = this.jTextField0.getText();
        String i = this.jTextField1.getText();
        String year = this.jTextField2.getText();
        String sum = this.jTextField3.getText();
        if(jComboBox0.getSelectedItem()=="复利计算"){
            f.calculate(p, i, year);
            this.jTextField3.setText(f.sum);
        }
        if(jComboBox0.getSelectedItem()=="求本金"){
            b.calculate(sum, i, year);
            this.jTextField0.setText(b.p);
        }
        if(jComboBox0.getSelectedItem()=="求利息"){
            l.calculate(p, sum, year);
            this.jTextField1.setText(l.i);
        }
        if(jComboBox0.getSelectedItem()=="求年限"){
            n.calculate(p, i, sum);
            this.jTextField2.setText(n.year);
        }
    }

}

 package com.zhadan.calculate;

import java.text.DecimalFormat;

public class Fuli {
    double sum2;
    public String sum;
    public void calculate(String p2,String i2,String year2){
        double p = Double.parseDouble(p2);
        double i = Double.parseDouble(i2);
        int year = Integer.parseInt(year2);
        for(int j=1;j<=year;j++){
            p=p+p*i;
            
        }
        DecimalFormat df=new DecimalFormat("0.0");
        sum2=p;
        sum=String.valueOf(df.format(sum2));
    }
}

package com.zhadan.calculate;

import java.text.DecimalFormat;

public class Benjin {
    double p2;
    public String p;
    public void calculate(String sum2,String i2,String year2){
        double sum = Double.parseDouble(sum2);
        double i = Double.parseDouble(i2);
        int year = Integer.parseInt(year2);
        i=1+i;
        for(int j=1;j<=year;j++){
            sum=sum/i;
        }
        DecimalFormat df=new DecimalFormat("0.0");
        Math.round(sum);
        p2=sum;
        p=String.valueOf(df.format(p2));
    }
}

package com.zhadan.calculate;

import java.text.DecimalFormat;

public class Lilv {
    double i2;
    public String i;
    public void calculate(String p2,String sum2,String year2){
        double p = Double.parseDouble(p2);
        double sum = Double.parseDouble(sum2);
        double year = Integer.parseInt(year2);
        DecimalFormat df=new DecimalFormat("0.0");
        i2=Math.pow(sum/p, 1/year)-1;
        i=String.valueOf(df.format(i2));
    }
}

package com.zhadan.calculate;

public class Nianxian {
    int year2=0;
    public String year;
    public void calculate(String p2,String i2,String sum2){
        double p = Double.parseDouble(p2);
        double i = Double.parseDouble(i2);
        double sum = Double.parseDouble(sum2);
        while(p<sum){
            for(int j=1;j<100;j++);{
                p=p*(1+i);
                year2++;
            }
        }
        year=String.valueOf(year2);
        System.out.println(year);
    }

}

队友谭宇森：http://www.cnblogs.com/dalaotan/p/5392039.html