使用反射技术构造对象

public class Bean {

    private int id;

    private String name;

    public int getId() {

       return id;

    }

    public void setId(int id) {

       this.id = id;

    }

    public String getName() {

       return name;

    }

    public void setName(String name) {

       this.name = name;

    }

    public Bean(String name){

       this.name=name;

    }

    public Bean(int id,String name){

       this.id=id;

       this.name=name;

    }

    public String toString() {

       return "id="+this.id+" name="+this.name;

    }

}

 

public class Bean2 {

    private String name;

    public String getName() {

       return name;

    }

    public void setName(String name) {

       this.name = name;

    }

    public Bean2(){

      

    }

    public Bean2(String name){

       this.name=name;

    }

    public String toString() {

       return "name="+this.name;

    }

}

测试：

public class ReflectTest {

 

    public static void main(String[] args) throws Exception {

       Bean2 b2=(Bean2) test1(Bean2.class);

       System.out.println(b2);

      

       Bean bean=(Bean)test2(Bean.class);

       System.out.println(bean);

       //传不同的Class就能得到不同的对象

       Bean2 b=(Bean2)test2(Bean2.class);

       System.out.println(b);

      

       Bean bea=(Bean)test3(Bean.class);

       System.out.println(bea);

      

    }

    public static Object test1(Class clazz) throws Exception{

       Object obj=null;

       obj=clazz.newInstance();//这种方式只能构造出有无参数的构造方法的对象出来      

       return obj;

    }

   

    public static Object test2(Class clazz) throws Exception{

       Object obj=null;

       Constructor con=clazz.getConstructor(String.class);//只要构造方法带有一个String型的对象都可以

       obj=con.newInstance("test2");

       return obj;

    }

   

    public static Object test3(Class clazz) throws Exception{

       Object obj=null;

       Constructor con=clazz.getConstructor(int.class,String.class);////只要构造方法带有一个int和String型的对象都可以，注意int与String顺序

       obj=con.newInstance(22,"张明学");

       return obj;

    }

}