1 package com.tn.collect; 2 3 import java.util.ArrayList; 4 import java.util.Iterator; 5 6 class Product{ 7 public Product() { 8 super(); 9 // TODO Auto-generated constructor stub 10 } 11 public Product(int id, String name, int price) { 12 // TODO Auto-generated constructor stub 13 setId(id); 14 setName(name); 15 setPrice(price); 16 } 17 private int id; 18 private String name; 19 private double price; 20 public int getId() { 21 return id; 22 } 23 public void setId(int id) { 24 this.id = id; 25 } 26 public String getName() { 27 return name; 28 } 29 public void setName(String name) { 30 this.name = name; 31 } 32 public double getPrice() { 33 return price; 34 } 35 public void setPrice(double price) { 36 this.price = price; 37 } 38 @Override 39 public String toString() { 40 return "Product [id=" + id + ", name=" + name + ", price=" + price 41 + "]"; 42 } 43 } 44 public class ArrayListLearning { 45 public static void main(String[] args){ 46 Product product1=new Product(1001,"奇瑞",99999); 47 Product product2=new Product(1002,"江淮",88888); 48 Product product3=new Product(1003,"比亚迪",77777); 49 ArrayList arrayList=new ArrayList(); 50 arrayList.add(product1); 51 arrayList.add(product2); 52 arrayList.add(product3); 53 System.out.println(arrayList);//会打印容器中每个对象的toString 54 System.out.println(arrayList.size()); 55 Object object=arrayList.get(0); 56 System.out.println(object); 57 Product product=(Product)arrayList.get(0); 58 System.out.println(arrayList.get(0)); 59 Product product4=new Product(1004,"力帆",66666); 60 Product product5=new Product(1005,"吉利",55555); 61 Product productx=new Product(1005,"吉利",55555); 62 ArrayList<Product> list=new ArrayList<Product>(); 63 list.add(product4); 64 list.add(product5); 65 Product product6=list.get(0); 66 System.out.println(product6); 67 68 //遍历方法一： 69 for(int i=0;i<list.size();i++){ 70 Product pro=list.get(i); 71 System.out.println(pro); 72 } 73 74 //遍历方法二： 75 Iterator<Product> iterator=list.iterator(); 76 while(iterator.hasNext()){ 77 Product pro=iterator.next(); 78 } 79 80 //遍历方法三： 81 for(Object obj:list){ 82 Product pro=(Product)obj; 83 } 84 85 System.out.println(list.contains(product5)); 86 System.out.println(list.contains(productx));//对象创建是两个，但实际应用中这两个对象应该是一个 87 } 88 }
运行结果：
[Product [id=1001, name=奇瑞, price=99999.0], Product [id=1002, name=江淮, price=88888.0], Product [id=1003, name=比亚迪, price=77777.0]]
3
Product [id=1001, name=奇瑞, price=99999.0]
Product [id=1001, name=奇瑞, price=99999.0]
Product [id=1004, name=力帆, price=66666.0]
Product [id=1004, name=力帆, price=66666.0]
Product [id=1005, name=吉利, price=55555.0]
true
false
1 package com.tn.collect; 2 3 import java.util.ArrayList; 4 import java.util.Iterator; 5 6 class Product{ 7 @Override 8 public boolean equals(Object obj) { 9 if (this == obj) 10 return true; 11 if (obj == null) 12 return false; 13 if (getClass() != obj.getClass()) 14 return false; 15 Product other = (Product) obj; 16 if (id != other.id) 17 return false; 18 return true; 19 } 20 public Product() { 21 super(); 22 // TODO Auto-generated constructor stub 23 } 24 public Product(int id, String name, int price) { 25 // TODO Auto-generated constructor stub 26 setId(id); 27 setName(name); 28 setPrice(price); 29 } 30 private int id; 31 private String name; 32 private double price; 33 public int getId() { 34 return id; 35 } 36 public void setId(int id) { 37 this.id = id; 38 } 39 public String getName() { 40 return name; 41 } 42 public void setName(String name) { 43 this.name = name; 44 } 45 public double getPrice() { 46 return price; 47 } 48 public void setPrice(double price) { 49 this.price = price; 50 } 51 @Override 52 public String toString() { 53 return "Product [id=" + id + ", name=" + name + ", price=" + price 54 + "]"; 55 } 56 } 57 public class ArrayListLearning { 58 public static void main(String[] args){ 59 Product product1=new Product(1001,"奇瑞",99999); 60 Product product2=new Product(1002,"江淮",88888); 61 Product product3=new Product(1003,"比亚迪",77777); 62 ArrayList arrayList=new ArrayList(); 63 arrayList.add(product1); 64 arrayList.add(product2); 65 arrayList.add(product3); 66 System.out.println(arrayList);//会打印容器中每个对象的toString 67 System.out.println(arrayList.size()); 68 Object object=arrayList.get(0); 69 System.out.println(object); 70 Product product=(Product)arrayList.get(0); 71 System.out.println(arrayList.get(0)); 72 Product product4=new Product(1004,"力帆",66666); 73 Product product5=new Product(1005,"吉利",55555); 74 Product productx=new Product(1005,"吉利",55555); 75 ArrayList<Product> list=new ArrayList<Product>(); 76 list.add(product4); 77 list.add(product5); 78 Product product6=list.get(0); 79 System.out.println(product6); 80 81 //遍历方法一： 82 for(int i=0;i<list.size();i++){ 83 Product pro=list.get(i); 84 System.out.println(pro); 85 } 86 87 //遍历方法二： 88 Iterator<Product> iterator=list.iterator(); 89 while(iterator.hasNext()){ 90 Product pro=iterator.next(); 91 } 92 93 //遍历方法三： 94 for(Object obj:list){ 95 Product pro=(Product)obj; 96 } 97 98 System.out.println(list.contains(product5)); 99 System.out.println(list.contains(productx));//对象创建是两个，但实际应用中这两个对象应该是一个 100 } 101 }
运行结果：
[Product [id=1001, name=奇瑞, price=99999.0], Product [id=1002, name=江淮, price=88888.0], Product [id=1003, name=比亚迪, price=77777.0]]
3
Product [id=1001, name=奇瑞, price=99999.0]
Product [id=1001, name=奇瑞, price=99999.0]
Product [id=1004, name=力帆, price=66666.0]
Product [id=1004, name=力帆, price=66666.0]
Product [id=1005, name=吉利, price=55555.0]
true
true