父类对象转成子类对象

import org.springframework.beans.BeanUtils;
import java.util.ArrayList;
import java.util.List;
public class Test {public static void main(String[] args) {List<B> bList = new ArrayList<>();B b = new B("a","这是a","b","这是b");bList.add(b);A a1 = new A("a","这是a");a1.setBusType(BusType.BUS_TYPE_FMDM);a1.setGatherType(AggrType.COUNT);B b1 = new B();BeanUtils.copyProperties(a1, b1);bList.add(b1);System.out.println(bList.toArray());}
}class A {private String code;private String title;private BusType busType = BusType.BUS_TYPE_NONE;private AggrType gatherType = AggrType.NONE;public A() {}public A(String code, String title) {this.code = code;this.title = title;}public String getCode() {return code;}public void setCode(String code) {this.code = code;}public String getTitle() {return title;}public void setTitle(String title) {this.title = title;}public BusType getBusType() {return busType;}public void setBusType(BusType busType) {this.busType = busType;}public AggrType getGatherType() {return gatherType;}public void setGatherType(AggrType gatherType) {this.gatherType = gatherType;}
}class B extends A{private String id;private String name;public B(String code, String title) {super(code, title);}public B(String code, String title, String id, String name) {super(code, title);this.id = id;this.name = name;}public B() {}public String getId() {return id;}public void setId(String id) {this.id = id;}public String getName() {return name;}public void setName(String name) {this.name = name;}
}