反射 reflection

public class TestJunit {  @BeforeClass public static void setUpBeforeClass() throws Exception { }    @Test public void reflectionTest() throws ClassNotFoundException, InstantiationException, IllegalAccessException, SecurityException, NoSuchMethodException, IllegalArgumentException, InvocationTargetException{   //give the class package string;定义包名字符串，此处可以在config配置文件中配置包名和类名，在这里来读。  String packageName = "com.neusoft.domain.User";   //get class by package name;根据包名获得类  Class cls = Class.forName(packageName);   //get the method by methodName and parameterTypes;得到一个带String类型参数的函数，函数名称为toString，即：toString(String str)  Method method = cls.getMethod("toString", String.class);   //instance the class;//实例化对象   Object x = cls.newInstance();    //define the parameters of constructor;定义构造函数需要用的参数   Object[] objarr = new Object[]{"China",5,"www.baidu.com"};     //invoke the method you have get；调用方法method即：toString方法  method.invoke(this.newInstance(cls.getName(), objarr), "I love you");    }    /**  * @author xuehf  * @作用：实例化带有多参数的构造函数；若有Integer类型的参数，则转换为int.class  * @function to instance an object that who has more than one parameter  use the constructor  * */ public  Object newInstance(String className,Object args[]) throws ClassNotFoundException, InstantiationException, IllegalAccessException, SecurityException, NoSuchMethodException, IllegalArgumentException, InvocationTargetException{  Class cls = Class.forName(className);  Class[] clsarr = new Class[args.length];  for(int i = 0;i<args.length;++i){   clsarr[i] = args[i].getClass();   if(clsarr[i].toString().equals("class java.lang.Integer")){    clsarr[i] = int.class;   }  }  Constructor cst = cls.getConstructor(clsarr);   return cst.newInstance(args);  } }//entity class;实体类public class User{   private String name;   private int  age;   private String email;   /**    *自动增加一些get，set方法吧     */      public void toString(String str){     System.out.println(this.name+str);   }     /**    * define the default constructor    */   public User(){}  /**    * define the multi-parameters constructor    */  public User(String name,int age,String email){       this.name=name;      this.age = age;       this.email = email;   }   }