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用Struts2实现在线银行付款

     摘要:                                  &n...  阅读全文

posted @ 2009-10-13 18:27 Jxi 阅读(1193) | 评论 (2) | 编辑 收藏

SSH基础搭建

 

                           Struts2+Hibernate3.0+Spring的基本搭建(非常基础的)

具体操作步骤截图见附件(源代码不包含lib包):S2SH截图
除了操作的配置代码:
WEB-INF下的web.xml的配置:

applicationContext.xml:

struts.xml:
hibernate.cfg.xml:什么都做，全交给Spring管理
WEB-INF下的数据库配置文件 jdbc.properties

posted @ 2009-09-30 15:29 Jxi 阅读(137) | 评论 (0) | 编辑 收藏

Spring @AspectJ

准备工作:需要  spring/lib/asm 下的3个包:asm.jar  asm-commons.jar asm-util.jar
spring/lib/aspectj  下的2个包 aspectjrt.jar  和aspectjweaver.jar
使用@AspectJ的小例子:

posted @ 2009-09-14 20:01 Jxi 阅读(150) | 评论 (0) | 编辑 收藏

Spring AOP 学习笔记

AOP  Aspect Oriented Programing  面向方面编程
AOP 术语
连接点:(Joinpoint)    程序执行的特定位置(类开始初始化前、类初始化后、调用前后、异常抛出后)
切点:   (PointCut)     程序类中客观存在的事物（类中的方法）
增强 :  (Advice)        置入到目标类Joinpint的一段代码
目标对象:(Target)   引介(Introduction)  织入(Weaving)  代理(Proxy) 切面(Aspect):切点和增强的组成 
 
基础知识: Spring Aop :使用动态代理技术在运行期间织入增强代码
ProxyFactory 代理工厂采用JDK代理或CGLib代理技术
JDK 动态代理:
1.定义UserService接口函数:

public interface UserService {
public void addUser(int id);
 }

2.UserServiceImpl

public class UserServiceImpl implements UserService{
 public void addUser(int id){
     System.out.println("添加一个用户中 ："+id);
 }
}

3.ProxyHandler

import java.lang.reflect.InvocationHandler;
import java.lang.reflect.Method;


public class ProxyHandler implements InvocationHandler{
   private Object target;
   public  ProxyHandler(Object target){
       this.target=target;
   }
   
public Object invoke(Object proxy, Method method, Object[] args)
        throws Throwable {
       System.out.println("添加用户前");
       Object obj=method.invoke(target,args);
       System.out.println("添加用户后");
       return obj;
}
}

TestProxyHandler

import java.lang.reflect.Proxy;

public class ProxyHandlerTest {
  public static void main(String args[]){
      UserService target=new UserServiceImpl();
      ProxyHandler handler=new ProxyHandler(target);
      UserService proxy=(UserService)Proxy.newProxyInstance(
        target.getClass().getClassLoader(),
        target.getClass().getInterfaces(),
        handler);
      proxy.addUser(100);
  }
}

CGLib 代理:
AddUserService接口:

package CGlib.Text.Service;

public interface AddUserService {
 public void addUser(int id);
}

AddUserServiceImpl 实现类:

package CGlib.Text.Service;

public class AddUserServiceImpl implements AddUserService {

    public void addUser(int id) {
        System.out.println("添加用户ID中:"+id);
    }
}

CglibProxy 代理类:

package CGlib.Text.Service;



import java.lang.reflect.Method;

import net.sf.cglib.proxy.Enhancer;
import net.sf.cglib.proxy.MethodInterceptor;
import net.sf.cglib.proxy.MethodProxy;

public class CglibProxy implements MethodInterceptor{
    private Enhancer enhancer=new Enhancer();
    @SuppressWarnings("unchecked")
    public Object getProxy(Class clazz){
        enhancer.setSuperclass(clazz);
        enhancer.setCallback(this);
        return enhancer.create();        
    }

    public Object intercept(Object obj, Method method, Object[] args,
            MethodProxy proxy) throws Throwable {
        System.out.println("添加用户之前");
        System.out.print(method.getName());
        System.out.print(obj.getClass().getName()+"外加");
        System.out.print(args.getClass().getName());
        Object result=proxy.invokeSuper(obj, args);
        System.out.println("外加的参数"+args.toString());
        System.out.println("添加用户之后");
        // TODO Auto-generated method stub
        return result;
    }
    

}

CglibProxyTest:测试类

package CGlib.Text.Service;

public class CglibProxyTest {
    public static void main(String[] args){
        CglibProxy proxy=new CglibProxy();
        AddUserServiceImpl userService=
            (AddUserServiceImpl)proxy.getProxy(AddUserServiceImpl.class);
      userService.addUser(100);        
    }

}

对JDK动态代理和Cglib动态代理的理解：
JDK   代理时性能高，但生成代理对象时运行性能较低
Cglib 代理时性能低，但生成代理对象时运行性能较高
所以：单例Singleton 时采用CGLib代理。

posted @ 2009-08-23 22:52 Jxi 阅读(132) | 评论 (0) | 编辑 收藏

Spring

 

Spring

Important

Spring is an application framework. Unlike single-tier frameworks such as Struts or Hibernate, Spring aims to help structure whole applications in a consistent, productive manner, pulling together best-of-breed single-tier frameworks to create a coherent architecture.

Problems with the Traditional Approach to J2EE

传统J2EE方法存在的问题

• J2EE applications tend to contain excessive amounts of "plumbing" code.多
• Many J2EE applications use a distributed object model where this is inappropriate.杂
• The EJB component model is unduly complex.不当
• EJB is overused.过度使用
• Many "J2EE design patterns" are not, in fact, design patterns, but workarounds for technology limitations.技术跟不上
• J2EE applications are hard to unit test.测试难
• Certain J2EE technologies have simply failed.

Enter Spring

接触Spring

• Inversion of Control container:倒置控制
• Aspect-Oriented Programming (AOP) framework:
• Data access abstraction:
• JDBC simplification:
• Transaction management:
• MVC web framework:
• Simplification for working with JNDI, JTA, and other J2EE APIs:
• Lightweight remoting:
• JMS support:
• JMX support:
• Support for a comprehensive testing strategy for application developers:

The key Spring values can be summarized as follows:

·         Spring is a non-invasive framework.非侵入

·         Spring provides a consistent programming model, usable in any environment.

·         Spring aims to promote code reuse.复用

·         Spring aims to facilitate Object Oriented design in J2EE applications.

·         Spring aims to facilitate good programming practice, such as programming to interfaces, rather than classes.面向接口

·         Spring promotes pluggability.性能

·         Spring facilitates the extraction of configuration values from Java code into XML or properties files.

·         Spring is designed so that applications using it are as easy as possible to test.

·         Spring is consistent.

·         Spring promotes architectural choice.

·         Spring does not reinvent the wheel.

posted @ 2009-07-25 14:57 Jxi 阅读(131) | 评论 (0) | 编辑 收藏