[Commons lang3 topic] 002 randomutils topic

【commons-lang3 project 】002- RandomUtils project

〇、 Get ready

1、RandomUtils The main role

Provide all kinds of Randomly generate all kinds of data Methods .

2、 Introduce dependencies

<!-- https://mvnrepository.com/artifact/org.apache.commons/commons-lang3 -->
<dependency>
    <groupId>org.apache.commons</groupId>
    <artifactId>commons-lang3</artifactId>
    <version>3.12.0</version>
</dependency>

One 、 Generate int value

1、 Generate [0, Integer.MAX_VALUE) Between random int value

// 1、 Generate  [0, Integer.MAX_VALUE)  Between random  int  value 
System.out.println(RandomUtils.nextInt()); // 150881120

2、 Generate [startInclusive,endExclusive) Random integer between , The starting value cannot be less than the ending value

// 2、 Generate  [startInclusive,endExclusive)  Random integer between , The starting value cannot be less than the ending value 
System.out.println(RandomUtils.nextInt(10, 20)); // 19

Two 、 Generate boolean value

3、 Randomly generate a Boolean value ,true perhaps false

// 3、 Randomly generate a Boolean value ,true  perhaps  false
System.out.println(RandomUtils.nextBoolean()); // true

3、 ... and 、 Generate long value

4、 Generate [0, Long.MAX_VALUE) Between long value

// 4、 Generate  [0, Long.MAX_VALUE)  Between  long  value 
System.out.println(RandomUtils.nextLong()); // 2331387764569299625

5、 Generate [startInclusive,endExclusive) Between random long value

// 5、 Generate  [startInclusive,endExclusive)  Between random  long  value 
System.out.println(RandomUtils.nextLong(10, 20)); // 12

Four 、 Generate byte array

6、 Generate a specified number of byte arrays

// 6、 Generate a specified number of byte arrays 
System.out.println(Arrays.toString(RandomUtils.nextBytes(5))); // [-81, 122, -126, -109, 2]

5、 ... and 、 Generate double value

7、 Generate [0, Double.MAX_VALUE) Between random double value

// 7、 Generate  [0, Double.MAX_VALUE)  Between random  double  value 
System.out.println(RandomUtils.nextDouble()); // 5.778886902758481E306

8、 Generate [startInclusive,endExclusive) Between random double value

// 8、 Generate  [startInclusive,endExclusive)  Between random  double  value 
System.out.println(RandomUtils.nextDouble(10, 20)); // 19.05143192281762

6、 ... and 、 Generate float value

9、 Generate [0, Float.MAX_VALUE) Between random float value

// 9、 Generate  [0, Float.MAX_VALUE)  Between random  float  value 
System.out.println(RandomUtils.nextFloat()); // 5.778886902758481E306

10、 Generate [startInclusive,endExclusive) Between random float value

// 10、 Generate  [startInclusive,endExclusive)  Between random  float  value 
System.out.println(RandomUtils.nextFloat(10, 20)); // 14.427974

7、 ... and 、 Complete code

package com.zibo.zibo2022.random_utils.main;

import org.apache.commons.lang3.RandomUtils;

import java.util.Arrays;

public class Main {
    

    public static void main(String[] args) {
    
        // start
        // 1、 Generate  [0, Integer.MAX_VALUE)  Between random  int  value 
        System.out.println(RandomUtils.nextInt()); // 150881120

        // 2、 Generate  [startInclusive,endExclusive)  Random integer between , The starting value cannot be less than the ending value 
        System.out.println(RandomUtils.nextInt(10, 20)); // 19

        // 3、 Randomly generate a Boolean value ,true  perhaps  false
        System.out.println(RandomUtils.nextBoolean()); // true

        // 4、 Generate  [0, Long.MAX_VALUE)  Between  long  value 
        System.out.println(RandomUtils.nextLong()); // 2331387764569299625

        // 5、 Generate  [startInclusive,endExclusive)  Between random  long  value 
        System.out.println(RandomUtils.nextLong(10, 20)); // 12

        // 6、 Generate a specified number of byte arrays 
        System.out.println(Arrays.toString(RandomUtils.nextBytes(5))); // [-81, 122, -126, -109, 2]

        // 7、 Generate  [0, Double.MAX_VALUE)  Between random  double  value 
        System.out.println(RandomUtils.nextDouble()); // 5.778886902758481E306

        // 8、 Generate  [startInclusive,endExclusive)  Between random  double  value 
        System.out.println(RandomUtils.nextDouble(10, 20)); // 19.05143192281762

        // 9、 Generate  [0, Float.MAX_VALUE)  Between random  float  value 
        System.out.println(RandomUtils.nextFloat()); // 5.778886902758481E306

        // 10、 Generate  [startInclusive,endExclusive)  Between random  float  value 
        System.out.println(RandomUtils.nextFloat(10, 20)); // 14.427974
        // end
    }

}