bigdecimal

在java中判断一个BigDecimal的金额是否大于0，通常用于两个金额差的比较。 具体做法： BigDecimal amount= new BigDecimal("100"); int i=amount.compareTo(BigDecimal.ZERO); if(i==-1){ //amount小于0 例如：amt=-10.00 } if(i==0){ //amount等于0， amt=0.00 } if(i==1){ //amount大于0 例如：amt=10.00 } 或者用 if(amount.equals(BigDecimal.ZERO)){ } 文章来源: https://blog.csdn.net/yurui829/article/details/91619171

版权声明：本文为博主原创文章，未经博主允许不得转载 https://blog.csdn.net/weixin_43835717/article/details/91491140 如果都使用if-else的话，就会使用代码变的臃肿，而且难以复用。那我们就可以根据不同的情况，将不同的方式封装成不同的策略，将策略与它的使用对象分离开来。 案例： 定义注解，标注范围 /** * @author Gjing * 价格范围注解 **/ @Target ( ElementType . TYPE ) @Retention ( RetentionPolicy . RUNTIME ) public @ interface PriceRegion { int min ( ) default 0 ; int max ( ) default Integer . MAX_VALUE ; } 具体策略 /** * @author Gjing * 抽象策略 **/ public interface Price { BigDecimal getPrice ( BigDecimal price ) ; } /** * @author Gjing * 会员,六折 **/ @PriceRegion ( min = 10000 , max = 20000 ) class Member implements Price {

四分位算法实例() 　　 实例1： 　　　　数据总量: 6, 47, 49, 15, 42, 41, 7, 39, 43, 40, 36 　　　　由小到大排列的结果: 6, 7, 15, 36, 39, 40, 41, 42, 43, 47, 49 　　　　一共 11 项 　　　　 Q1 的位置= （11+1） × 0.25=3 ， Q2 的位置= （11+1）× 0.5=6 ， Q3 的位置= （11+1） × 0.75=9 　　　　 Q1 = 15 ， 　　　　 Q2 = 40 ， 　　　　 Q3 = 43 　　 实例 2 ： 　　　　数据总量: 7, 15, 36, 39, 40, 41 　　　　一共 6 项 　　　　数列项为偶数项时，四分位数 Q2 为该组数列的中数， 　　　　 （n+1）/4= 7/4 =1.75 ， Q1 在第一与第二个数字之间， 　　　　3（n+1）/4= 21/4 =5.25, Q3 在第五与第六个数字之间， 　　　 　Q1 = 0.75*15+0.25*7 = 13， 　　　　Q2 = （36+39）/2= 37.5， 　　　　Q3 = 0.25*41+0.75*40 = 40.25. Java 代码 1 public static void fourDivsion(double[] param){ 2 if(param == null ||

After going through the previous develop's trainwreck of code I realized I need to move all of the money based columns to not use floating point math. On the Java side this means using BigDecimal but when using Hibernate/JPA and MySQL 5 what would be the appropriate MySQL data type to make that column? Abimaran Kugathasan DECIMAL and NUMERIC. The recommended Java mapping for the DECIMAL and NUMERIC types is java.math.BigDecimal. The java.math.BigDecimal type provides math operations to allow BigDecimal types to be added, subtracted, multiplied, and divided with other BigDecimal types, with

I am developing an application using oracle 11g, Java(struts2) and Hibernate. I have table named mytemp with column mytemp_id which is of type NUMBER(22,0). In my mytemp.hbm.xml file id is as given below <id name="mytempId" type="big_decimal"> <column name="MYTEMP_ID" precision="22" scale="0" /> <generator class="sequence"> <param name="sequence">MYTEMP_TEMP_ID_SEQ</param> </generator> </id> In my Oracle database sequence named "MYTEMP_TEMP_ID_SEQ" is created and working fine in Oracle. Now when I try to insert record using hibernate, it gives me following error org.hibernate.id

I know variants of this question have been asked frequently before (see here and here for instance), but this is not an exact duplicate of those. I would like to check if a String is a number, and if so I would like to store it as a double . There are several ways to do this, but all of them seem inappropriate for my purposes. One solution would be to use Double.parseDouble(s) or similarly new BigDecimal(s) . However, those solutions don't work if there are commas present (so "1,234" would cause an exception). I could of course strip out all commas before using these techniques, but that would

I have a domain class with unitPrice set as BigDecimal data type. Now I am trying to create a method to compare price but it seems like I can't have comparison operators in BigDecimal data type. Do I have to change data type or is there other way around? Simulant Every object of the Class BigDecimal has a method compareTo you can use to compare it to another BigDecimal. The result of compareTo is then compared > 0 , == 0 or < 0 depending on what you need. Read the documentation and you will find out. The operators == , < , > and so on can only be used on primitive data types like int , long ,

Math类概述 Math类概述 Math 类包含用于执行基本数学运算的方法，如初等指数、对数、平方根和三角函数。 成员变量 public static final double E : 自然底数 public static final double PI: 圆周率 成员方法 public static int abs(int a) 取绝对值 public static double ceil(double a) 向上取整 public static double floor(double a) 向下取整 public static int max(int a,int b) 获取最大值 public static int min(int a, int b) 获取最小值 public static double pow(double a,double b) 获取a的b次幂 public static double random() 获取随机数 返回带正号的 double 值，该值大于等于 0.0 且小于 1.0。 public static int round(float a) 四舍五入 public static double sqrt(double a)获取正平方根 public static double cbrt(double a)获取立方根 Random类的使用