Java计算器源码（只实现了加减乘除四种简单的运算）：
1 import java.math.BigDecimal; 2 import java.text.Format; 3 public class Caculator { 4 private BigDecimal num1; 5 private BigDecimal num2; 6 private String result; 7 8 public void setNum1(double num1) { 9 this.num1 = new BigDecimal(num1); 10 } 11 12 public void setNum2(double num2) { 13 this.num2 = new BigDecimal(num2); 14 } 15 private double _format(){ 16 BigDecimal _num1 = new BigDecimal(result); 17 BigDecimal _num2 = new BigDecimal(1); 18 return _num1.divide(_num2, 5,BigDecimal.ROUND_HALF_UP).doubleValue(); 19 } 20 public String getResult() { 21 if(!result.equals("ERROR")) 22 { 23 double _res = _format(); 24 if(_res>=Double.MAX_VALUE||_res<=-Double.MAX_VALUE) 25 result = "ERROR"; 26 else 27 result = Double.toString(_format()); 28 } 29 return result; 30 } 31 public void Add() { 32 BigDecimal _result; 33 _result = num1.add(num2); 34 result = _result.toString(); 35 } 36 public void Sub() { 37 BigDecimal _result; 38 _result = num1.subtract(num2); 39 result = _result.toString(); 40 } 41 public void Mul() { 42 BigDecimal _result; 43 _result = num1.multiply(num2); 44 result = _result.toString(); 45 } 46 public void Div() { 47 BigDecimal _result; 48 if(num2.doubleValue()!=0){ 49 _result = num1.divide(num2); 50 result = _result.toString(); 51 } 52 else 53 result = "ERROR"; 54 } 55 } |
设计测试用例：
