java129-hashmap的方法

import java.util.Date;
 public class Car {
     private String brand;//品牌
     private Date createDate;
     private int housepower;//马力
     private int speed;//速度
     public void setBrand(String brand) {
         this.brand = brand;
     }
     public String getBrand() {
         return brand;
     }
     public Date getCreateDate() {
         return createDate;
     }
     public void setCreateDate(Date createDate) {
         this.createDate = createDate;
     }
     public void setHousepower(int housepower) {
         this.housepower = housepower;
     }
     public int getHousepower() {
         return housepower;
     }
     public void setSpeed(int speed) {
         this.speed = speed;
     }
     public int getSpeed() {
         return speed;
     }
 }
 测试类import java.util.*;
 public class test68 {
     public static void main(String[] args) {
         Car c0 = new Car();
         c0.setBrand("宝马");
         c0.setCreateDate(new Date());
         c0.setHousepower(4);
         c0.setSpeed(200);
         Car c1 = new Car();
         c1.setBrand("创奇");
         c1.setCreateDate(new Date());
         c1.setHousepower(5);
         c1.setSpeed(220);
         Car c2 = new Car();
         c2.setBrand("发力");
         c2.setCreateDate(new Date());
         c2.setHousepower(4);
         c2.setSpeed(240);
         Car c3 = new Car();
         c3.setBrand("丰田");
         c3.setCreateDate(new Date());
         c3.setHousepower(4);
         c3.setSpeed(230);
         //Car c4 = c3;
        // c4.setBrand("大众");
         //c4.setCreateDate(new Date());
         //c4.setHousepower(4);
         //c4.setSpeed(230);
         //添加hashmap的对象
         Map carMap = new HashMap();
         //使用put添加对象
         carMap.put("k1", c0);
         carMap.put("k2", c1);
         carMap.put("k3", c2);
         carMap.put("k4", c3);
         //carMap.put("k4",c4);
         //使用get返回自己需要的值
         Object obj = carMap.get("k4");
         if (obj != null) {
             Car target = (Car) obj;
             System.out.println(target.getBrand() + target.getHousepower());
         } else {
             System.out.println("未找到");
         }
         /*获取map集合的所有值*/
         Set keySet = carMap.keySet();
         Car c = null;
         for (Object k : keySet) {
             Car temp = (Car) carMap.get(k);
             System.out.println(temp.getBrand() + temp.getHousepower() + temp.getSpeed());
         }
         /*获取所有值对象*/
         Collection coll = carMap.values();
         for (Object v : coll) {
             System.out.println(((Car) v).getBrand());
         }
         /*判断是否包含某个给定的key*/
         boolean boo = carMap.containsKey("k9");
         System.out.println("是否包含k9" + boo);
         System.out.println(carMap.containsValue(c3));
         /*移除键值对象*/
         if (carMap.containsKey("k3")) {
             Object removeobj = carMap.remove("k3");
             System.out.println(((Car) removeobj).getBrand());
         }
         System.out.println(carMap.size());
     }
 }