定义一个汽车类

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;}
}

定义一个测试类

import java.util.Date;
import java.util.HashMap;
import java.util.Map;
public class test67 {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");}}
}

运行结果