package ClassTest.ClassFieldsTest;

import java.lang.reflect.Constructor;
import java.lang.reflect.Field;
import java.lang.reflect.InvocationTargetException;

/**
 * FileName: ReflectDemo01
 * Author:   lps
 * Date:     2022/4/11 18:21
 * Sign:劉品水 Q：1944900433
 * Field getField(String name) 返回一個 Field物件，該物件反映由該 Class物件表示的類或介面的指定公共成員欄位。
 * Field[] getFields() 返回一個包含 Field物件的陣列， Field物件反映由該 Class物件表示的類或介面的所有可訪問的公共欄位。
 * Field getDeclaredField(String name) 返回一個 Field物件，該物件反映由該 Class物件表示的類或介面的指定宣告欄位。
 * Field[] getDeclaredFields() 返回一個 Field物件的陣列，反映了由該 Class物件表示的類或介面宣告的所有欄位。
 
 
*/
public class ReflectDemo01 {
    public static void main(String[] args) throws ClassNotFoundException, NoSuchFieldException, NoSuchMethodException, InvocationTargetException, InstantiationException, IllegalAccessException {
        Class<?> c = Class.forName("ClassTest.ClassTest01.Student");
        Field[] fields 
 
= c.getFields();
        for (Field field:fields){
            System.out.println(field);
        }
        System.out.println("==========");
        Field[] declaredFields = c.getDeclaredFields();
        for (Field field:declaredFields){
            System.out.println(field);
        }
        System.out.println(
 
"=============");
        Field adressfield = c.getField("adress");
        //獲取無參構造方法建立物件
        Constructor<?> con = c.getConstructor();
        Object obj = con.newInstance();
        //Field提供有關類或介面的單個欄位的資訊和動態訪問
        //void set(Object obj, Object value) 將指定的物件引數中由此 Field物件表示的欄位設定為指定的新值。
        adressfield.set(obj,"南京");//給obj的成員變數adressfield賦值為南京
        System.out.println(obj);


    }
}

package ClassTest.ClassTest01;

/**
 * FileName: Student
 * Author:   lps
 * Date:     2022/4/11 15:22
 * Sign:劉品水 Q：1944900433
 */
public class Student {
    private String name;
    int age;
    public String adress;

    public Student() {
    }

    private Student(String name) {
        this.name = name;
    }

    Student(String name, int age) {
        this.name = name;
        this.age = age;
    }

    public Student(String name, int age, String adress) {
        this.name = name;
        this.age = age;
        this.adress = adress;
    }

    private void function(){
        System.out.println("function");
    }
    public void method1(){
        System.out.println("method");
    }
    public void method2(String s){
        System.out.println("method:"+s);
    }
    public String method3(String s, int i){
        return s+","+i;
    }

    @Override
    public String toString() {
        return "Student{" +
                "name='" + name + '\'' +
                ", age=" + age +
                ", adress='" + adress + '\'' +
                '}';
    }
}