public class Demo {private String key1 = "1";private String key2 = "2";public String getKey1() {return key1;}public void setKey1(String key1) {this.key1 = key1;}public String getKey2() {return key2;}public void setKey2(String key2) {this.key2 = key2;}public static void main(String[] args) throws Exception {//引數 “Demo” 是類的全名，如果在包結構下，要有完整包路徑 比如： com.test.DemoClass<?> clazz = Class.forName("Demo");//“Demo”類必須有預設構造方法，否則會丟擲異常Demo demo = (Demo) clazz.newInstance();System.out.println(demo.getKey1());System.out.println(demo.getKey2());}}

呼叫執行時類本身的.class屬性

Class clazz=Person.class;

//建立class對應的執行時類Person物件

System.out.println(clazz);

Class clazz1=String.class;

System.out.println(clazz1);

執行時類的物件獲取

Person p=new Person();

Class clazz2=p.getClass();

System.out.println(clazz2);

透過Class的靜態方法獲取

String className="test.Person";

Class clazz3=Class.forName(className);

System.out.println(clazz3);

透過類的載入器

ClassLoader classLoader=this.getClass().getClassLoader();

Class clazz4=classLoader.loadClass(className);

System.out.println(clazz4);