[Commons lang3 topic] 005- objectutils topic

【commons-lang3 project 】005- ObjectUtils project

〇、 Get ready

1、ObejctUtils The main role

Provide and generate various The object operation Method .

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>

3、 Entity class

Dog

package com.zibo.zibo2022.object_utils.entity;

import lombok.AllArgsConstructor;
import lombok.Data;
import lombok.NoArgsConstructor;

@Data
@NoArgsConstructor
@AllArgsConstructor
public class Dog {
    
    /** *  name  */
    private String name;

    /** *  Age  */
    private Integer age;

    /** * son */
    private Dog son;
}

DogCloneable

package com.zibo.zibo2022.object_utils.entity;

import lombok.AllArgsConstructor;
import lombok.Data;
import lombok.NoArgsConstructor;

@Data
@NoArgsConstructor
@AllArgsConstructor
public class DogCloneable implements Cloneable {
    

    /** *  name  */
    private String name;

    /** *  Age  */
    private Integer age;

    /** * son */
    private DogCloneable son;

    //  The following method is to use  idea  Generated 
    @Override
    public DogCloneable clone() {
    
        try {
    
            DogCloneable clone = (DogCloneable) super.clone();
            // TODO: copy mutable state here, so the clone can't change the internals of the original
            return clone;
        } catch (CloneNotSupportedException e) {
    
            throw new AssertionError();
        }
    }
}

One 、 Judge empty and non empty

1、 Determine whether the value of any element in a given array is not null

// 1、 Determine whether the value of any element in a given array is not  null
System.out.println(ObjectUtils.allNotNull("a", "b", "c")); // true
System.out.println(ObjectUtils.allNotNull("", "b", "c")); // true
System.out.println(ObjectUtils.allNotNull(null, "b", "c")); // false

2、 Determine whether the value of any element in a given array is null

// 2、 Determine whether the value of any element in a given array is  null
System.out.println(ObjectUtils.allNull(null, null, null)); // true
System.out.println(ObjectUtils.allNull("a", null, null)); // false

3、 Determine whether the elements in a given array have no null Value

// 3、 Determine whether the elements in a given array have no  null  Value 
System.out.println(ObjectUtils.anyNotNull("a", "b", "c")); // true
System.out.println(ObjectUtils.anyNotNull(null, "b", "c")); // true
System.out.println(ObjectUtils.anyNotNull(null, null, null)); // false

4、 Determine whether the elements in a given array have yes null Value

// 4、 Determine whether the elements in a given array have yes  null  Value 
System.out.println(ObjectUtils.anyNull("a", "b", "c")); // false
System.out.println(ObjectUtils.anyNull(null, "b", "c")); // true

Two 、 Clone objects - Shallow clone

5、 Clone objects - If the object implements Cloneable Clone , Otherwise null- Shallow clone

// 5、 Clone objects - If the object implements Cloneable Clone , Otherwise null- Shallow clone 
DogCloneable son = new DogCloneable("son", 1, null);
DogCloneable dog = new DogCloneable("zibo", 2, son);
System.out.println(dog);
// DogCloneable(name=zibo, age=2, son=DogCloneable(name=son, age=1, son=null))
DogCloneable cloneDog = ObjectUtils.clone(dog);
System.out.println(cloneDog);
// DogCloneable(name=zibo, age=2, son=DogCloneable(name=son, age=1, son=null))
son.setName("son2");
System.out.println(cloneDog);
//  Shallow clone 
// DogCloneable(name=zibo, age=2, son=DogCloneable(name=son2, age=1, son=null))

6、 Clone objects , If you return null , Returns the original object - Shallow clone

// 6、 Clone objects , If you return  `null` , Returns the original object - Shallow clone 
//  First tune  clone(final T obj) , If you return  null, Return to the original  obj  object 
Dog son1 = new Dog("son", 1, null);
Dog dog1 = new Dog("zibo", 2, son1);
Dog cloneIfPossible = ObjectUtils.cloneIfPossible(dog1);
System.out.println(cloneIfPossible);
//  Unrealized  `Cloneable`  Interface , return  `null` , Return to the original object 
// Dog(name=zibo, age=2, son=Dog(name=son, age=1, son=null))

3、 ... and 、 Compare the size

7、 Compare the size

// 7、 Compare the size 
//  grammar ：int compare(T c1, T c2)
//  The rules ： If  c1 < c2, Then return to  -1 ; If  c1 > c2, Then return to  +1 ; If  c1 = c2, Then return to  0;
System.out.println(ObjectUtils.compare(1, 20)); // -1
System.out.println(ObjectUtils.compare(20, 1)); // 1
System.out.println(ObjectUtils.compare(1, 1)); // 0
System.out.println(ObjectUtils.compare("1", "1")); // 0
System.out.println(ObjectUtils.compare("10", "1")); // 1
System.out.println(ObjectUtils.compare("a", "a")); // 0
System.out.println(ObjectUtils.compare("a", "b")); // -1
System.out.println(ObjectUtils.compare(null, "b")); // -1
System.out.println(ObjectUtils.compare("a", null)); // 1
System.out.println();

8、 Compare the size -null More valuable

// 8、 Compare the size -null More valuable 
//  Note the difference from the above 
System.out.println(ObjectUtils.compare(1, 20, true)); // -1
System.out.println(ObjectUtils.compare(null, 20, true)); // 1
System.out.println(ObjectUtils.compare(1, null, true)); // -1
System.out.println(ObjectUtils.compare(null, null, true)); // 0

Four 、 by null The default value is

9、 If the object is null , Return default

// 9、 If the object is  null , Return default 
System.out.println(ObjectUtils.defaultIfNull(null, " The default value is ")); //  The default value is 

5、 ... and 、 Object empty

10、 Determines if the object is null

// 10、 Determines if the object is null 
//  Support ：CharSequence、Array、Collection、Map
System.out.println(ObjectUtils.isEmpty("")); // true
System.out.println(ObjectUtils.isEmpty(Arrays.asList("hello", "world"))); // false
System.out.println(ObjectUtils.isEmpty(new HashMap<>())); // true
System.out.println(ObjectUtils.isEmpty(new Integer[]{
    })); // true

11、 Judge whether the object is not empty

// 11、 Judge whether the object is not empty 
//  Support ：CharSequence、Array、Collection、Map
System.out.println(ObjectUtils.isNotEmpty("")); // false
System.out.println(ObjectUtils.isNotEmpty(Arrays.asList("hello", "world"))); // true
System.out.println(ObjectUtils.isNotEmpty(new HashMap<>())); // false
System.out.println(ObjectUtils.isNotEmpty(new Integer[]{
    })); // false

6、 ... and 、 Get extreme values

12、 Get the maximum

// 12、 Get the maximum 
System.out.println(ObjectUtils.max(1, 2, 3, 4, 5)); // 5

13、 Get the minimum

// 13、 Get the minimum 
System.out.println(ObjectUtils.min(1, 2, 3, 4, 5)); // 1

14、 Get the median

// 14、 Get the median 
System.out.println(ObjectUtils.median(1, 2, 3, 4, 5)); // 3

7、 ... and 、 Complete code

package com.zibo.zibo2022.object_utils.main;

import com.zibo.zibo2022.object_utils.entity.Dog;
import com.zibo.zibo2022.object_utils.entity.DogCloneable;
import org.apache.commons.lang3.ObjectUtils;

import java.util.Arrays;
import java.util.HashMap;

public class Main {
    

    public static void main(String[] args) {
    
        // start
        //  One 、 Judge empty and non empty 
        // 1、 Determine whether the value of any element in a given array is not  null
        System.out.println(ObjectUtils.allNotNull("a", "b", "c")); // true
        System.out.println(ObjectUtils.allNotNull("", "b", "c")); // true
        System.out.println(ObjectUtils.allNotNull(null, "b", "c")); // false

        // 2、 Determine whether the value of any element in a given array is  null
        System.out.println(ObjectUtils.allNull(null, null, null)); // true
        System.out.println(ObjectUtils.allNull("a", null, null)); // false

        // 3、 Determine whether the elements in a given array have no  null  Value 
        System.out.println(ObjectUtils.anyNotNull("a", "b", "c")); // true
        System.out.println(ObjectUtils.anyNotNull(null, "b", "c")); // true
        System.out.println(ObjectUtils.anyNotNull(null, null, null)); // false

        // 4、 Determine whether the elements in a given array have yes  null  Value 
        System.out.println(ObjectUtils.anyNull("a", "b", "c")); // false
        System.out.println(ObjectUtils.anyNull(null, "b", "c")); // true

        //  Two 、 Clone objects - Shallow clone 
        // 5、 Clone objects - If the object implements Cloneable Clone , Otherwise null- Shallow clone 
        DogCloneable son = new DogCloneable("son", 1, null);
        DogCloneable dog = new DogCloneable("zibo", 2, son);
        System.out.println(dog);
        // DogCloneable(name=zibo, age=2, son=DogCloneable(name=son, age=1, son=null))
        DogCloneable cloneDog = ObjectUtils.clone(dog);
        System.out.println(cloneDog);
        // DogCloneable(name=zibo, age=2, son=DogCloneable(name=son, age=1, son=null))
        son.setName("son2");
        System.out.println(cloneDog);
        //  Shallow clone 
        // DogCloneable(name=zibo, age=2, son=DogCloneable(name=son2, age=1, son=null))

        // 6、 Clone objects , If you return  `null` , Returns the original object - Shallow clone 
        //  First tune  clone(final T obj) , If you return  null, Return to the original  obj  object 
        Dog son1 = new Dog("son", 1, null);
        Dog dog1 = new Dog("zibo", 2, son1);
        Dog cloneIfPossible = ObjectUtils.cloneIfPossible(dog1);
        System.out.println(cloneIfPossible);
        //  Unrealized  `Cloneable`  Interface , return  `null` , Return to the original object 
        // Dog(name=zibo, age=2, son=Dog(name=son, age=1, son=null))

        //  3、 ... and 、 Compare the size 
        // 7、 Compare the size 
        //  grammar ：int compare(T c1, T c2)
        //  The rules ： If  c1 < c2, Then return to  -1 ; If  c1 > c2, Then return to  +1 ; If  c1 = c2, Then return to  0;
        System.out.println(ObjectUtils.compare(1, 20)); // -1
        System.out.println(ObjectUtils.compare(20, 1)); // 1
        System.out.println(ObjectUtils.compare(1, 1)); // 0
        System.out.println(ObjectUtils.compare("1", "1")); // 0
        System.out.println(ObjectUtils.compare("10", "1")); // 1
        System.out.println(ObjectUtils.compare("a", "a")); // 0
        System.out.println(ObjectUtils.compare("a", "b")); // -1
        System.out.println(ObjectUtils.compare(null, "b")); // -1
        System.out.println(ObjectUtils.compare("a", null)); // 1
        System.out.println();

        // 8、 Compare the size -null More valuable 
        //  Note the difference from the above 
        System.out.println(ObjectUtils.compare(1, 20, true)); // -1
        System.out.println(ObjectUtils.compare(null, 20, true)); // 1
        System.out.println(ObjectUtils.compare(1, null, true)); // -1
        System.out.println(ObjectUtils.compare(null, null, true)); // 0

        //  Four 、 by  `null`  The default value is 
        // 9、 If the object is  null , Return default 
        System.out.println(ObjectUtils.defaultIfNull(null, " The default value is ")); //  The default value is 

        //  5、 ... and 、 Object empty 
        // 10、 Determines if the object is null 
        //  Support ：CharSequence、Array、Collection、Map
        System.out.println(ObjectUtils.isEmpty("")); // true
        System.out.println(ObjectUtils.isEmpty(Arrays.asList("hello", "world"))); // false
        System.out.println(ObjectUtils.isEmpty(new HashMap<>())); // true
        System.out.println(ObjectUtils.isEmpty(new Integer[]{
    })); // true

        // 11、 Judge whether the object is not empty 
        //  Support ：CharSequence、Array、Collection、Map
        System.out.println(ObjectUtils.isNotEmpty("")); // false
        System.out.println(ObjectUtils.isNotEmpty(Arrays.asList("hello", "world"))); // true
        System.out.println(ObjectUtils.isNotEmpty(new HashMap<>())); // false
        System.out.println(ObjectUtils.isNotEmpty(new Integer[]{
    })); // false

        //  6、 ... and 、 Get extreme values 
        // 12、 Get the maximum 
        System.out.println(ObjectUtils.max(1, 2, 3, 4, 5)); // 5

        // 13、 Get the minimum 
        System.out.println(ObjectUtils.min(1, 2, 3, 4, 5)); // 1

        // 14、 Get the median 
        System.out.println(ObjectUtils.median(1, 2, 3, 4, 5)); // 3
        // end
    }

}