作业（8月29）

1. 将今天学习的到的dbutils源码加以理解并重新敲一次

2. 写一个工具类，完成Javabean的对象拷贝

示例代码：

public class People {
    private String userName;
    private Integer age;

    public String getUserName() {
        return userName;
    }

    public void setUserName(String userName) {
        this.userName = userName;
    }

    public Integer getAge() {
        return age;
    }

    public void setAge(Integer age) {
        this.age = age;
    }
}

public class Student {
    private Integer stuNum;
    private String userName;
    private Integer age;

    public Integer getStuNum() {
        return stuNum;
    }

    public void setStuNum(Integer stuNum) {
        this.stuNum = stuNum;
    }

    public String getUserName() {
        return userName;
    }

    public void setUserName(String userName) {
        this.userName = userName;
    }

    public Integer getAge() {
        return age;
    }

    public void setAge(Integer age) {
        this.age = age;
    }
}

//编写工具类BeanUtils
public class BeanUtils {
  //拷贝属性的方法,bean是被拷贝的的对象，clazz是要拷贝的class
  public static <T> T copyProperties(Object bean, Class<T> clazz) {
      //实现拷贝逻辑, 只要class中有属性名和bean相同的就执行拷贝
        // todo
  }
}

//测试
public class Test {
  public static void main(String[] args) {
    People p = new People();
    p.setUserName("user1");
    p.setAge(21);
    //执行拷贝，将userName和age的值拷贝到Student同名的属性中，并返回Student实例
    Student stu = BeanUtils.copyProperties(p, Student.class);
    System.out.println(stu.getUserName());
    System.out.println(stu.getAge());
  }
}

### 3. 熟读阿里巴巴开发手册第一部分