java:常用类库api

 

 

 

package com.vince;

import java.util.Arrays;

public class StringDemo2 {

    public static void main(String[] args) {
        
        String str = " fkwefwfa d6737383 ";
        char c = str.charAt(1);
        System.out.println(c);
        
        System.out.println(str.toCharArray());
        char[] cs = {'a','b','c'};
        String s1 = new String(cs);
        
        String s2 = new String(cs,0,1);
        System.out.println(s2);
        
        System.out.println(Arrays.toString(str.getBytes()));
        
        System.out.println(str.replace('w', '*'));
        System.out.println(str.replaceAll("\\d", "*"));
        
        System.out.println(str.substring(0, 4));
        
        System.out.println(Arrays.toString(str.split("d")));
        
        System.out.println(str.contains("a"));
        
        System.out.println(str.indexOf("f"));
        System.out.println(str.lastIndexOf("f"));
        System.out.println(str.isEmpty());
        
        System.out.println(str.length());
        
        System.out.println(str.trim());
        
        System.out.println(str.concat("*****"));
        System.out.println(String.valueOf(10));
    }

}

 

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package com.vince;

/**
 * 对象需要具备克隆功能：
 * 1、实现Cloneable接口,(标记接口)
 * 2、重写Object类中的clone方法
 * @author vince
 * @description
 */
public class Cat implements Cloneable{
    private String name;
    private int age;
    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }
    public int getAge() {
        return age;
    }
    public void setAge(int age) {
        this.age = age;
    }
    public Cat(String name, int age) {
        super();
        this.name = name;
        this.age = age;
    }
    public Cat() {
        super();
    }
    //重写Object中的clone方法
    @Override
    protected Object clone() throws CloneNotSupportedException {
        return super.clone();
    }
    @Override
    public String toString() {
        return "Cat [name=" + name + ", age=" + age + "]";
    }
    
}

package com.vince;

import java.io.IOException;

public class Test {

    public static void main(String[] args) {

        Cat cat = new Cat("ίχίχΠʽ°Χ",2);
        try {
            Cat newCat = (Cat) cat.clone();
            
            
            System.out.println("cat="+cat);
            System.out.println("new cat="+newCat);
            System.out.println(cat==newCat);
        } catch (CloneNotSupportedException e) {
            e.printStackTrace();
        }
        
    }

}

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