java计算器，没用代码，紧急！！

[刘掌柜的]

这两段代码在最后好像没用的，求高人指点下
public static String round(double v, int scale) {
if (scale < 0) {
throw new IllegalArgumentException(
"The scale must be a positive integer or zero");
}
BigDecimal b = new BigDecimal(Double.toString(v));
BigDecimal one = new BigDecimal("1");
return String.valueOf(b.divide(one, scale, BigDecimal.ROUND_HALF_UP));
}


public static String round(String v, int String, int scale) {
if (scale < 0) {
throw new IllegalArgumentException(
"The scale must be a positive integer or zero");
}
BigDecimal b = new BigDecimal(v);
BigDecimal one = new BigDecimal("1");

b.divide(one, scale, BigDecimal.ROUND_HALF_UP);

return null;
}

[ghostkngiht]

return null;???????

[william_yao]

两段代码要人怎么看。。。

[刘掌柜的]

就是这些 package com.math.tools; import java.math.BigDecimal; public class Arith { private static final int DEF_DIV_SCALE=10; private Arith(){ ; } public static String add(double v1,double v2){ BigDecimal b1=new BigDecimal(Double.toString(v1)); BigDecimal b2=new BigDecimal(Double.toString(v2)); return String.valueOf(b1.add(b2)); } public static String add(String v1,String v2){ BigDecimal b1=new BigDecimal(v1); BigDecimal b2=new BigDecimal(v2); return String.valueOf(b1.add(b2)); } public static String sub(double v1,double v2){ BigDecimal b1=new BigDecimal(Double.toString(v1)); BigDecimal b2=new BigDecimal(Double.toString(v2)); return String.valueOf(b1.subtract(b2)); } public static String sub(String v1,String v2){ BigDecimal b1=new BigDecimal(v1); BigDecimal b2=new BigDecimal(v2); return String.valueOf(b1.subtract(b2)); } public static String mul(double v1,double v2){ BigDecimal b1=new BigDecimal(Double.toString(v1)); BigDecimal b2=new BigDecimal(Double.toString(v2)); return String.valueOf(b1.multiply(b2)); } public static String mul(String v1,String v2){ BigDecimal b1=new BigDecimal(v1); BigDecimal b2=new BigDecimal(v2); return String.valueOf(b1.multiply(b2)); } public static String div(double v1,double v2){ return div(v1,v2,DEF_DIV_SCALE); } public static String div(String v1,String v2){ return div(v1,v2,DEF_DIV_SCALE); } public static String div(double v1, double v2, int scale){ if(scale<0){ throw new IllegalArgumentException( "the scale must be a positive integer or zero"); } BigDecimal b1=new BigDecimal(Double.toString(v1)); BigDecimal b2=new BigDecimal(Double.toString(v2)); return String.valueOf(b1.divide(b2,scale,BigDecimal.ROUND_HALF_UP)); } public static String div(String v1,String v2,int scale){ if(scale<0){ throw new IllegalArgumentException( "the scale must be a positive integer or zero"); } BigDecimal b1=new BigDecimal(v1); BigDecimal b2=new BigDecimal(v2); BigDecimal result=null; try{ result=b1.divide(b2); }catch (Exception e){ result =b1.divide(b2,scale,BigDecimal.ROUND_HALF_UP); } return String.valueOf(result); } public static String round(double v,int scale){ if(scale<0){ throw new IllegalArgumentException("the scale integer or zero"); } BigDecimal b=new BigDecimal(Double.toString(v)); BigDecimal one=new BigDecimal("1"); return String.valueOf(b.divide(one,scale,BigDecimal.ROUND_HALF_UP)); } public static String round(String v,int String,int scale){ if(scale<0){ throw new IllegalArgumentException( "interger or int"); } BigDecimal b=new BigDecimal(v); BigDecimal one=new BigDecimal("1"); b.divide(one,scale,BigDecimal.ROUND_HALF_UP); return null; } }

[代码间的舞者]

引用 3 楼 u010214802 的回复:

public static String round(String v,int String,int scale){ if(scale<0){ throw new IllegalArgumentException( "interger or int"); } BigDecimal b=new BigDecimal(v); BigDecimal one=new BigDecimal("1"); b.divide(one,scale,BigDecimal.ROUND_HALF_UP); return null; } }

这段代码要这么改

public static String round(String v, int string, int scale) {
		 if (scale < 0) {
			 throw new IllegalArgumentException(
			 "The scale must be a positive integer or zero");
		 }
		 BigDecimal b = new BigDecimal(v);
		 BigDecimal one = new BigDecimal(string);
		 return String.valueOf(b.divide(one, scale, BigDecimal.ROUND_HALF_UP));
		
	 }