import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
import java.util.Date;
public class RateanLoan extends JFrame implements ActionListener
{
JButton Rate=new JButton("汇率计算器");
JButton Loan=new JButton("贷款计算器");
JTextField jtf;
JLabel jl1;
JLabel jl2;
JLabel jl3;
JTextField rmb;
JTextField dollar;
JTextField result;
JButton run;
JFrame f1,f2;
JTextField jtfAnnualInterestRate;
JTextField jtfNumberOfYears;
JTextField jtfLoanAmount;
JTextField jtfMonthlyPayment;
JTextField jtfTotalPayment;
public RateanLoan()
{
super("贷款及汇率换算程序");
setSize(600,500);
setVisible(true);
setLayout(new FlowLayout());
add(Rate,"打开汇率计算器");
add(Loan,"打开贷款计算器");
}
public void actionPerformed(ActionEvent e)
{
if(e.getSource()==Rate)
{
new rateFrame();
}
else if(e.getSource()==Loan)
{
new loanFrame();
}
}
class rateFrame extends JFrame
{
f1=new JFrame("汇率计算器");
Container container=f1.getContentPane();
f1.setVisible(true);
f1.setSize(300, 300);
f1.setLayout(new GridLayout(3,1,10,10));
JPanel jp1=new JPanel(new BorderLayout());
jl1=new JLabel("汇率:");
f1.setDefaultCloseOperation(EXIT_ON_CLOSE);
jp1.add(BorderLayout.WEST,jl1);
jtf=new JTextField(getWidth()/3);
jtf.setText("6.5785");
jp1.add(BorderLayout.CENTER,jtf);
container.add(jp1);
JPanel jp2=new JPanel(new GridLayout(1,4));
jl2=new JLabel("人民币");
jp2.add(jl2);
rmb=new JTextField(" ");
jp2.add(rmb);
jl3=new JLabel("美元:");
jp2.add(jl3);
result=new JTextField;
jp2.add(result);
container.add(jp2);
JPanel jp3=new JPanel();
run=new JButton("计算");
jp3.add(run);
container.add(jp3);
run.addActionListener(new ActionListener()
{
double hv=Double.parseDouble(jtf.getText().toString());
double r=Double.parseDouble(rmb.getText().toString());
double a=r/hv;
result.setText(toString(a));
}
class loanFrame extends JFrame
{
f2=new JFrame("贷款计算器");
f2.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
f2.setVisible(true);
JPanel p1=newJPanel(new GridLayout(5,2);
jtfAnnualInterestRate=new JTextField("Annual Interest Rate");
jtfNumberOfYears=new JTextField("NumberOfYears");
jtfLoanAmount=new JTextField("LoanAmount");
jtfMonthlyPayment=new JTextField("MonthlyPayment");
jtfTotalPayment=new JTextField("TotalPayment");
p1.add(new JLabel("Annual Interest Rate"));
p1.add(jtfAnnualInterestRate);
p1.add(new JLabel("Number of Years"));
p1.add(jtfNumberOfYears);
p1.add(new JLabel("Loan Amount"));
p1.add(jtfLoanAmount);
p1.add(new JLabel("Monthly Payment"));
p1.add(jtfMonthlyPayment);
p1.add(new JLabel("Total Payment"));
p1.add(jtfTotalPayment);
p1.setBorder(new TitledBorder("请输入金额,贷款率,年数");
JPanel p2=new JPanel(new FlowLayout(FlowLayout.RIGHT));
p2.add(jbtComputeLoan);
add(p1,BorderLayout.CENTER);
add(p2,BorderLayout.SOUTH);
jbtComputeLoan.addActionListener(new ButtonListener());
public void actionPerformed(ActionEvent e)
{
double interest=Double.parseDouble(jtfAnnualInterestRate.getText());
int year=Integer.parseInt(jtfNumberOfYears.getText());
double loanAmount=Double.parseDouble(jtfLoanAmount.getText());
double monthlyInterest=interest/1200;
double monthlyPayment= loanAmount*monthlyInterest/(1-1/Math.pow(1+monthlyInterest,year*12));
double totalPayment=monthlyPayment*year*12;
jtfMonthlyPayment.setText(String.format("%.2f", monthlyPayment));
jtfTotalPayment.setText(String.format("%.2f", totalPayment));
}
}
public static void main(String[] args)
{
new RateanLoan();
}
}
