标签：book ide family lan getc test etc 实例化 构造方法
实例化对象的两种形式：
1）通过关键字new
2）通过反射机制完成
package test;
//Book类
class Book {
private String title;
private double price;
public void setPric(double price) {
this.price = price;
}
public void setTitle(String title) {
this.title = title;
}
@Override
public String toString() {
return "图书名称:"+ title + " 价格:" + price;
}
}
public class TestReflection {
public static void main(String[] args) throws Exception {
Class<?> cls = Class.forName("test.Book"); //包名.类名
Book book = (Book) cls.newInstance();
book.setTitle("Java");
book.setPric(10.01);
System.out.println(book.toString()); //图书名称:Java 价格:10.01
}
}
Q：如果类中没有提供无参构造方法，只提供了有参构造方法，则必须明确调用指定的构造方法才可以通过反射实例化对象
package test;
import java.lang.reflect.Constructor;
//Book类
class Book {
private String title;
private double price;
public Book(String title,double price){
this.price = price;
this.title = title;
}
@Override
public String toString() {
return "图书名称:"+ title + " 价格:" + price;
}
}
public class TestReflection {
public static void main(String[] args) throws Exception {
Class<?> cls = Class.forName("test.Book");
Constructor<?> cons = cls.getConstructor(String.class,double.class);
Book book = (Book) cons.newInstance("Java",10.01);
System.out.println(book.toString()); //图书名称:Java 价格:10.01
}
}
标签：book ide family lan getc test etc 实例化 构造方法
原文地址：https://www.cnblogs.com/wuyuwuyueping/p/9391636.html
