loantest.java

还不错的java基本实例

/**
 * Created by IntelliJ IDEA.
 * User: shaohj
 * Date: 2005-8-30
 * Time: 18:17:33
 * To change this template use File | Settings | File Templates.
 */
import javax.swing.JOptionPane;
import java.text.*;
public class LoanTest {
    public static void main(String[] args) {
              //声明3个变量
             double aloanAmount, monthlyPayment, totalPayment ;

             //创建贷款计算器对象
            Loan aLoan=new Loan();
             //调用贷款计算器对象的setLoanAmount方法
             // 将贷款计算机对象贷款数量的值设置为20000.0
             aLoan.setLoanAmount(20000.0);
             // 调用贷款计算器对象的setLoanPeriod方法
             //将贷款周期属性的值设置为12（单位年）
             aLoan.setYears(12);
             //调用贷款计算器对象的setAnnualInterestRate方法
             //将年利率属性的值设置为7（即7%）
             aLoan.setAnnualInterestRate(7.0f);

             //调用贷款计算器对象的computeMonthlyPayment方法计算月付款
             // 并将方法的返回值付给变量 monthlyPayment
              monthlyPayment=aLoan.computeMonthlyPayment();
            //调用贷款计算器对象的computeTotalPayment方法计算总付款
             // 并将方法的返回值付给变量totalPayment
              totalPayment=aLoan.computeTotalPayment();
             // 调用贷款计算器对象的getLoanAmount方法读取贷款数量属性的值
              aloanAmount=aLoan.getLoanAmount();

             //调NumberFormat类的getCurrencyInstance
             // 创建 NumberFormat对象currencyformatter
             //准备将指定数值的格式化为货币
             NumberFormat currencyformatter=NumberFormat.getCurrencyInstance();
              //连接字符串付给String类型的变量output
              String output="贷款金额：  "+currencyformatter.format(aloanAmount)+"\n"+
                       "贷款周期： "+aLoan.getMonths()+"（月）\n"+
                      "年利率： "+aLoan.getAnnualInterestRate()+"%"+"\n"+
                      "月付款： "+currencyformatter.format(monthlyPayment)+"\n"+
                      "总付款： "+ currencyformatter.format(totalPayment)+"\n\n";

               aLoan.setMonths(24);
               monthlyPayment = aLoan.computeMonthlyPayment();
               totalPayment = aLoan.computeTotalPayment() ;
               output+="贷款金额：  "+currencyformatter.format(aloanAmount)+"\n"+
                               "贷款周期： "+aLoan.getYears()+"（年）\n"+
                              "年利率： "+aLoan.getAnnualInterestRate()+"%"+"\n"+
                              "月付款： "+currencyformatter.format(monthlyPayment)+"\n"+
                              "总付款： "+ currencyformatter.format(totalPayment)+"\n";

             //在消息框中显示字符串output
              JOptionPane.showMessageDialog( null,output,
                      "结果",+JOptionPane.INFORMATION_MESSAGE);
              System.exit(0);
    }
}