JAvaSE(04)(equalsメソッド)

    ：
package zz.itheima.equals;
//   
public class Animal {
    /** * 1.equals    object ，     （    ）     (   )   * 2.                 * 3.         equals   */
    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 Animal(String name, int age) {
        super();
        this.name = name;
        this.age = age;
    }
    public Animal() {
        super();
    }

    //equals    （   ）
    public boolean equals(Object o){
        //1.                               ，        
        //2、this      ，    animal，==                  
        if (this==o) {
            return true;
        }else {//       
            if(o instanceof Animal){//                             
                //                    
                Animal other = (Animal)o;//    
                if (this.name.equals(other.getName())&&this.age==other.getAge()) {
                    return true;
                }else {
                    return false;
                }
            }else {//                  
                return false;
            }

        }

    }


}
package zz.itheima.equals;
//  
public class Book {
    private String name;
    private double price;
    private int isbn;
    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }
    public double getPrice() {
        return price;
    }
    public void setPrice(double price) {
        this.price = price;
    }
    public int getIsbn() {
        return isbn;
    }
    public void setIsbn(int isbn) {
        this.isbn = isbn;
    }
    public Book(String name, double price, int isbn) {
        super();
        this.name = name;
        this.price = price;
        this.isbn = isbn;
    }
    public Book() {
        super();
    }
    //  hashcode
    public int hashCode(){
        return isbn + name.hashCode() + (int )price;
    }
    //  toString  
    public String toString(){
        return "isbn" + isbn + "  :" + name + "  ：" + price;
    }




}
package zz.itheima.equals;

public class TestAnimal {

    public static void main(String[] args) {
        /** * 1.==            ，                   ，               ==，       ， *       ，         ，              。 * */
        int j1 = 10;
        int j2 = 10;
        Animal a1 = new Animal();
        a1.setName("a");
        Animal a2 = new Animal();
        a2.setName("a");
        Animal a3 = a1;
        System.out.println(j1==j2);//       true；
        System.out.println(a1==a2);//a1 a2     ，     ，   false
        System.out.println(a1==a3);// a1       a3,   true
        System.out.println(a1.equals(new Book()));//          false；
    }

}
package zz.itheima.equals;

public class TestBook {

    public static void main(String[] args) {
        //  hashcode
        Book b1 = new Book("aaa", 10.0, 1);
        Book b2 = new Book("aaa", 10.0, 1);
        System.out.println(b1.hashCode());//    
        System.out.println(b2.hashCode());//hashcode              （  @       ），        hashcode。
    }

}
//          
package zz.itheima.equals;

public class TestGetCalss {

    public static void main(String[] args) {
        //           
        Book b = new Book();
        Class c = b.getClass();
        System.out.println(c.getName());//       ：zz.itheima.equals.Book
    }

}
//  toString  
package zz.itheima.equals;

public class TesttoString {

    public static void main(String[] args) {
        //  toString（）  
        Animal animal = new Animal();
        System.out.println(animal);//               @   。
    }

}