In fact, online about Bigdecimal There are many documents about the operation of , Here is a summary , Put these routine operations into a document , For future viewing

Bigdecimal Addition, subtraction, multiplication and division

BigDecimal b1 = new BigDecimal("10");
BigDecimal b2 = new BigDecimal("5");
BigDecimal b3 = null;

// Add 
b3 = b1.add(b2);
System.out.println("b1 + b2 =" + b3);// Output 15

// Subtraction 
b3 = b1.subtract(b2);
System.out.println("b1 - b2 = " + b3);// Output 5

// Multiplication 
b3 = b1.multiply(b2);
System.out.println("b1 * b2 = " + b3);// Output 50

// division 
b3 = b1.divide(b2);
System.out.println("b1 / b2 = " + b3);// Output 2

Bigdecimal Compare the size of

BigDecimal a = new BigDecimal("10");
BigDecimal b = new BigDecimal("5");

if(a.compareTo(b) == -1){
    
    System.out.println("a Less than b");
}

 if(a.compareTo(b) == 0){
    
     System.out.println("a be equal to b");
 }

 if(a.compareTo(b) == 1){
    
     System.out.println("a Greater than b");
 }

 if(a.compareTo(b) > -1){
    
     System.out.println("a Greater than or equal to b");
 }

 if(a.compareTo(b) < 1){
    
     System.out.println("a Less than or equal to b");
 }

Bigdecimal Rounding up and rounding down

BigDecimal a = new BigDecimal("0.9");
System.out.println(" Rounding down ：" + a.setScale(0,BigDecimal.ROUND_FLOOR));

BigDecimal b = new BigDecimal("0.1");
System.out.println(" Rounding up ：" + b.setScale(0,BigDecimal.ROUND_UP));

Judge BigDecimal Is there a decimal

BigDecimal b = new BigDecimal(20.5);
if (new BigDecimal(b.intValue()).compareTo(b) != 0) {
    
	System.out.println("b  Is the decimal ");
} else {
    
	System.out.println("b  Is an integer ");
}

Bigdecimal Set accumulation of

image Bigdecimal Cumulative scenes are rare , Although not common , But there will be , unfortunately , I'll use it today （ Smile to cry ~）, So also record this .

There are two scenarios , One is that the set is directly Bigdecimal Of , as follows

 List<BigDecimal> list = new ArrayList<>();

Another is in the form of set objects , Then there are Bigdecimal Properties of type , as follows

List<Employee> list = new ArrayList<>();

// You can see Employee There is an attribute in the class salary, The type is Bigdecimal

@Data
public class Employee {
    
    private int id;
    private String name;
    private int age;
    private BigDecimal salary;
}

Accumulation method of scenario one

List<BigDecimal> list = new ArrayList<>();
list.add(new BigDecimal("1"));
list.add(new BigDecimal("2"));
list.add(new BigDecimal("3"));

BigDecimal decimal = list.stream().reduce(BigDecimal.ZERO, BigDecimal::add);
System.out.println(decimal);  // Output 6

Accumulation method of scenario 2 ： Get... From the object

List<Employee> list = new ArrayList<>();

list.add(new Employee(1," Wang ba ",BigDecimal.valueOf(5)));
list.add(new Employee(2," Chu Yuan ",BigDecimal.valueOf(10)));

BigDecimal result = list.stream()
     //  take Employee Object's salary out  map Return to Bigdecimal
     .map(Employee::getSalary)
     //  Use reduce() Aggregate functions , Implement accumulator 
     .reduce(BigDecimal.ZERO,BigDecimal::add);

System.out.println(result);// Output 15

The above two methods mainly use JDK8 In new features Stream, If you don't understand, you can check this article ：JDK8 New characteristics - Detailed explanation

because Bigdecimal Similar ones are commonly used in actual development , Make a special note to deepen your influence , Of course , If it helps you , It's also my pleasure ~