public interface Calculator {
  public int calculate( int a , int b);
}

public class CalculatorImpl implements Calculator {
  @Override
  public int calculate(int a, int b) {
    return a/b;
  }
}

public class SomeHandler implements InvocationHandler {
 
// Code omitted for simplicity…..
 
  @Override
  public Object invoke(Object proxy, Method method, Object[] params) throws Throwable {
// Your complex business validation and logic
    Object result = method.invoke(targetObject ,params);
    return result;
  }
 
}

public static void main(String[] args) {
    CalculatorImpl calcImpl = new CalculatorImpl();
    Calculator proxied = (Calculator)ProxyFactory.getProxy (Calculator.class, calcImpl, 
        new SomeHandler(calcImpl));
    int result = proxied.calculate(20, 10);
    System.out.println("FInal Result :::" + result);
  }

public interface UserBean 
{ 
  void getUser(); 
  void addUser(); 
  void updateUser(); 
  void deleteUser(); 
} 

public class UserBeanImpl implements UserBean 
{ 
  private String user = null; 
  public UserBeanImpl() 
  {     
  }   
  public UserBeanImpl(String user) 
  { 
    this.user = user; 
  }   
  public String getUserName() 
  { 
    return user; 
  }   
  public void getUser() 
  { 
    System.out.println("this is getUser() method!"); 
  } 
 
  public void setUser(String user) 
  { 
    this.user = user; 
    System.out.println("this is setUser() method!"); 
  } 
  public void addUser() 
  { 
    System.out.println("this is addUser() method!"); 
  } 
   
  public void updateUser() 
  { 
    System.out.println("this is updateUser() method!"); 
  }   
  public void deleteUser() 
  { 
    System.out.println("this is deleteUser() method!");  
  }     
} 

import java.lang.reflect.InvocationHandler; 
import java.lang.reflect.Method; 
import java.lang.reflect.Proxy; 
import com.cignacmc.finance.bean.UserBeanImpl; 
 
public class UserBeanProxy implements InvocationHandler 
{ 
  private Object targetObject; 
   
  public UserBeanProxy(Object targetObject) 
  { 
    this.targetObject = targetObject;     
  } 
   
  public Object invoke(Object proxy, Method method, Object[] args) throws Throwable 
  { 
    UserBeanImpl userBean = (UserBeanImpl) targetObject; 
    String userName = userBean.getUserName(); 
    Object result = null; 
     
    //权限判断 
    if(userName != null && !"".equals(userName)) 
    { 
      result = method.invoke(targetObject, args); 
    } 
     
    return result; 
  } 
} 

import java.lang.reflect.Proxy; 
 
import com.cignacmc.finance.bean.UserBean; 
import com.cignacmc.finance.bean.UserBeanImpl; 
import com.cignacmc.finance.proxy.UserBeanProxy; 
 
public class ProxyExe 
{ 
  public static void main(String[] args) 
  { 
    System.out.println("Proved............."); 
    UserBeanImpl targetObject = new UserBeanImpl("Bob Liang");    
    UserBeanProxy proxy = new UserBeanProxy(targetObject); 
    //生成代理对象     
    UserBean object = (UserBean)Proxy.newProxyInstance(targetObject.getClass().getClassLoader(),  
        targetObject.getClass().getInterfaces(), proxy); 
    object.addUser(); 
     
    System.out.println("NO Proved............."); 
    targetObject = new UserBeanImpl();    
    proxy = new UserBeanProxy(targetObject); 
    //生成代理对象     
    object = (UserBean)Proxy.newProxyInstance(targetObject.getClass().getClassLoader(),  
        targetObject.getClass().getInterfaces(), proxy); 
    object.addUser(); 
         
  } 
} 

Proved............. 
this is addUser() method! 
NO Proved............. 

public class ClientBean 
{ 
  private String name = null; 
 
  public ClientBean() 
  { 
 
  } 
 
  public ClientBean(String name) 
  { 
    this.name = name; 
  } 
 
  public void addClient() 
  { 
    System.out.println("this is addClient() method!"); 
  } 
 
  public void deleteClient() 
  { 
    System.out.println("this is deleteClient() method!"); 
  } 
 
  public void getClient() 
  { 
    System.out.println("this is getClient() method!"); 
  } 
 
  public void updateClient() 
  { 
    System.out.println("this is updateClient() method!"); 
  } 
 
  public String getClientName() 
  { 
    return name; 
  } 
 
  public void setClientName(String name) 
  { 
    this.name = name; 
  } 
} 

import java.lang.reflect.Method; 
 
import com.cignacmc.finance.bean.ClientBean; 
 
import net.sf.cglib.proxy.Enhancer; 
import net.sf.cglib.proxy.MethodInterceptor; 
import net.sf.cglib.proxy.MethodProxy; 
 
public class CGLibProxy implements MethodInterceptor 
{ 
  private Object targetObject; 
   
  public Object createProxyObject(Object targetObject) 
  { 
    this.targetObject = targetObject; 
    Enhancer enhancer = new Enhancer(); 
    enhancer.setSuperclass(this.targetObject.getClass()); 
    enhancer.setCallback(this); 
    return enhancer.create(); 
  } 
   
  public Object intercept(Object proxy, Method method, Object[] args, MethodProxy methodProxy) throws Throwable 
  { 
    ClientBean clientBean = (ClientBean)targetObject; 
    String userName = clientBean.getClientName(); 
    Object result = null; 
     
    if(userName != null && !"".equals(userName)) 
    { 
      result = method.invoke(targetObject, args); 
    } 
    return result; 
  } 
} 

import java.lang.reflect.Proxy; 
 
import com.cignacmc.finance.bean.ClientBean; 
import com.cignacmc.finance.bean.UserBean; 
import com.cignacmc.finance.bean.UserBeanImpl; 
import com.cignacmc.finance.proxy.CGLibProxy; 
import com.cignacmc.finance.proxy.UserBeanProxy; 
 
public class ProxyExe 
{ 
  public static void main(String[] args) 
  {   
    System.out.println(".............CGLIB Proxy...................."); 
    System.out.println("Proved...................."); 
    CGLibProxy cproxy = new CGLibProxy(); 
    ClientBean clientBean = (ClientBean)cproxy.createProxyObject(new ClientBean("Bob Liang")); 
    clientBean.addClient(); 
     
    System.out.println("NO Proved...................."); 
    cproxy = new CGLibProxy(); 
    clientBean = (ClientBean)cproxy.createProxyObject(new ClientBean()); 
    clientBean.addClient(); 
         
  } 
} 

.............CGLIB Proxy.................... 
Proved.................... 
this is addClient() method! 
NO Proved....................