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金家寶 — Sun, 01 Apr 2007 05:50:00 GMT

摘要: March 02, 2007 根据petclinic项目手把手教你剖析SpringFramework源代码-日志篇[转] 关键词:Spring,log4j在petclinic项目中，在web.xml有几个条目和log4j有关，它们是: 继续阅读 "根据petclinic项目手... 阅读全文

金家寶 2007-04-01 13:50 发表评论

实战MVC模式

金家寶 — Thu, 08 Mar 2007 17:40:00 GMT

内容:
1.MVC
2.Observer接口
3.模型Model
4.视图View
5.控制器Controller
6.运行程序

--------------------------------------------------------------------------------

MVC

“模型－视图－控制器(Model-View-Controller,MVC)结构是为那些需要为同样的数据提供多个视图的应用程序而设计的，它很好的实现了数据层与表示层的分离。例如下图中的例子：
=700) window.open('http://www.cs.nyu.edu/courses/spring99/V22.0480-001/lectures/images/l14_im2.JPG');" src="http://www.cs.nyu.edu/courses/spring99/V22.0480-001/lectures/images/l14_im2.JPG" onload="if(this.width > 700)this.width = 700;if(this.height > 700) this.height = 700;" border="0" />
我们看到，图中的几组数据以不同的形式(View)表现出来，一个是表格样式，一个是图形样式。

MVC把这种应用程序分为三种对象类型:
模型：维护数据并提供数据访问方法。
视图：给制模型的部分数据或所有数据的可视图。
控制器：处理事件.
以下是典型的MVC通信方式,
=700) window.open('http://www.javable.com/columns/serv_side/workshop/11/1.gif');" src="http://www.javable.com/columns/serv_side/workshop/11/1.gif" onload="if(this.width > 700)this.width = 700;if(this.height > 700) this.height = 700;" border="0" />

事件由控制器来处理，控制器接收用户事件，并根据事件的类型来改变模型。
视图事先会在模型中登记，当模型数据发生改变时，马上通知已向此模型登记的每个视图。
视图从模取得最新的数据并刷新自己.
要实现MVC，最重要的一个环节是使用Design  Pattern中的Observer模式。Observer模式允许某个对象在所观察的对象发生修改时通知多个观察者(Observer).

下面我们就以实例来讲解如何用Obserer模式实现MVC的程序结构。在我的例子中，我要实现一个学生年龄显示的例子。分别用清单和图形的方式显示每个学生的年龄。当年龄改变时，自动更新显示。

Observer接口

为了实现观察的对象发生修改时通知多个观察者，通常要在被观察者与观察者之间有一个小的接口，如下:
/*  file:  Observer.java  */
public  interface  Observer
{
        public  void  dataUpdate(Model  model);
}
这个接口中有一个dataUpdate(Model  model)方法，只要实现了这个接口对象，就成了一个观察者。

模型Model

再来建立一个数据模型。在我的例子中，先建立了一个数据对象:
/*  file:  Data.java  */
public  class  Data
{
        public  int  value;　　//  学生年龄值
        public  String  name;　//  学生名
}
现在来建立一个Model:
/*  file:  Model.java  */
import  java.util.*;
public  class  Model
{
        ArrayList  data  =  new  ArrayList();
        ArrayList  observer  =  new  ArrayList();
        public  Model()
        {        super();
        }
        public  Model(int[]  value,  String[]  name)
        {
                for  (  int  i  =  0;  i<  value.length;  i++
                {
                        addData(value,name);
                }
        }
        public  Model(Data[]  data)
        {
                for  (  int  i  =  0;  i<  data.length;  i++
                {
                        addData(data);
                }
        }
        public  void  addData(int  value,  String  name)
        {
                Data  data  =  new  Data();
                data.value  =  value;
                data.name  =  name;
                this.data.add(data);
        }
        public  void  addData(Data  data)
        {
                this.data.add(data);
        }
        public  Data  getData(int  idx)
        {
                return  (Data)(data.get(idx));
        }

        public  int  size()
        {
                return  data.size();
        }
　　//  用来向模型中登记观察者.
        public  void  registerObserver(Observer  o)
        {
                observer.add(o);
        }
        public  void  removeObserver(Observer  o)
        {
                observer.remove(o);
        }
        //  当数据改变时，由Controller调用此方法，通知各个Observer,刷新视图.
        public  void  changeModel(Model  model)
        {
                data.clear();
                for  (int  i=0;  i
                {
                        this.addData(model.getData(i));
                }
                dataUpdate();
        }
        private  void  dataUpdate()
        {
                for  (Iterator  i  =  observer.iterator();  i.hasNext();
                {
                        Observer  o  =  (Observer)(i.next());
                        o.dataUpdate(this);
                }
        }
}
这个模型提供各种数据访问的方法。并提供一个changeModel(Model  model)方法供Controller访问。还提供一个registerObserver(Observer  o)方法，用来向Model中登记观察者Observer。

视图View

我们要实现一个清单显示样式的视图View1和一个图形方式显示的视图View2,并让它们实现Observer接口，以便当Model数据改变时，自动刷新自己.
/*  file:  View1.java  */
import  javax.swing.*;
import  java.awt.*;
import  javax.swing.border.*;
public  class  View1  extends  JPanel  implements  Observer
{
        Model  model;

        public  View1()
        {
        }
        public  View1(Model  model)
        {
                try
                {
                        this.model  =  model;
                        jbInit();
                }
                catch(Exception  e)
                {
                        e.printStackTrace();
                }
        }
        private  void  jbInit()  throws  Exception
        {
                this.setBackground(Color.white);
                this.setBorder(new  TitledBorder(BorderFactory.createLineBorder(Color.black,1),"View1");
        }

        public  void  paintComponent(Graphics  g)
        {
                super.paintComponent(g);
                if  (  model  ==  null    return;
                int  x  =  20,y  =  50;
                int  h  =  g.getFontMetrics().getHeight();
                for  (  int  i=0;  i<  model.size();  i++
                {
                        Data  data  =  model.getData(i);
                        g.drawString(data.name,x,y);
                        y+=h;
                        g.drawString(String.valueOf(data.value),x,y);
                        y+=h;
                }
        }
        //  当模型数据发生改变时，会自动调用此方法来刷新图形
        public  void  dataUpdate(Model  model)
        {
                /**@todo:  Implement  this  Observer  method*/
                this.model  =  model;
                repaint();
        }
}
/*  file:  View2.java  */
import  javax.swing.*;
import  java.awt.*;
import  javax.swing.border.*;
public  class  View2  extends  JPanel  implements  Observer
{
        Model  model;

        public  View2()
        {
        }
        public  View2(Model  model)
        {
                try
                {
                        this.model  =  model;
                        jbInit();
                }
                catch(Exception  e)
                {
                        e.printStackTrace();
                }
        }
        private  void  jbInit()  throws  Exception
        {
                this.setBackground(Color.white);
                this.setBorder(new  TitledBorder(BorderFactory.createLineBorder(Color.black,1),"View1");
        }

        public  void  paintComponent(Graphics  g)
        {
                super.paintComponent(g);
                if  (  model  ==  null    return;
                int  x  =  20,y  =  50;
                int  h  =  g.getFontMetrics().getHeight();
                int  width  =  this.getWidth();
                int  height  =  this.getHeight();
                int  sy  =  height  /  model.size();
                int  sx  =  width/  2;
                for  (  int  i=0;  i<  model.size();  i++
                {
                        Data  data  =  model.getData(i);
                        int  value  =  data.value;
                        int  dx  =  3;
                        int  r  =  3;
                        Color  c  =  new  Color((int)(255*Math.random()),(int)(255*Math.random()),(int)(255*Math.random()));
                        int  cx  =  sx;
                        int  cy  =  y+i  *  sy;
                        for  (  int  j=0;j
                        {
                                g.setColor(c);
                                g.drawOval(cx,cy,r,r);
                                r+=dx;
                        }
                        g.drawString(data.name,25,cy);
                }
        }
        //  当模型数据发生改变时，会自动调用此方法来刷新图形
        public  void  dataUpdate(Model  model)
        {
                /**@todo:  Implement  this  Observer  method*/
                this.model  =  model;
                repaint();
        }
}

控制器Controller

好了，MVC中的Model,Observer都建立好了，我们最后来做一个Controller:
import  java.awt.*;
import  javax.swing.*;
import  javax.swing.border.*;
import  java.awt.event.*;
public  class  Controller  extends  JFrame
{
        Model  model  =    new  Model();
        View1  view1  =  new  View1(model);
        View2  view2  =  new  View2(model);
        JScrollPane  jScrollPane1  =  new  JScrollPane();
        JButton  jButton1  =  new  JButton();
        JTextField  jTextField1  =  new  JTextField();
        JTextField  jTextField2  =  new  JTextField();
        JLabel  jLabel1  =  new  JLabel();
        JLabel  jLabel2  =  new  JLabel();
        JLabel  jLabel3  =  new  JLabel();
        public  Controller()
        {
                try
                {
                        jbInit();
                }
                catch(Exception  e)
                {
                        e.printStackTrace();
                }

        }
        private  void  jbInit()  throws  Exception
        {
                Data[]  data  =  new  Data[2];
                data[0]  =  new  Data();
                data[1]  =  new  Data();
                data[0].name  =  "Ted";
                data[0].value  =  20;
                data[1].name  =  "Joy";
                data[1].value  =  14;
                model.addData(data[0]);
                model.addData(data[1]);
                //  注意下面两行：向模型中登记它的观察者View1和View2.
                model.registerObserver(view1);
                model.registerObserver(view2);

                this.getContentPane().setLayout(null);
                jScrollPane1.setBounds(new  Rectangle(0,  0,  3,  3));
                jButton1.setBounds(new  Rectangle(309,  259,  101,  27));
                jButton1.setText("Update";
                jButton1.addActionListener(new  java.awt.event.ActionListener()
                {
                        public  void  actionPerformed(ActionEvent  e)
                        {
                                jButton1_actionPerformed(e);
                        }
                });
                jTextField1.setText("20";
                jTextField1.setBounds(new  Rectangle(80,  254,  52,  30));
                jTextField2.setText("14";
                jTextField2.setBounds(new  Rectangle(178,  255,  50,  31));
                jLabel1.setText("Age:";
                jLabel1.setBounds(new  Rectangle(41,  226,  47,  23));
                jLabel2.setText("Ted";
                jLabel2.setBounds(new  Rectangle(42,  252,  35,  33));
                jLabel3.setText("Joy";
                jLabel3.setBounds(new  Rectangle(144,  255,  31,  31));
                view1.setBounds(new  Rectangle(7,  5,  225,  20);
                view2.setBounds(new  Rectangle(234,  4,  219,  209));
                this.getContentPane().add(jScrollPane1,  null);
                this.getContentPane().add(jTextField2,  null);
                this.getContentPane().add(jTextField1,  null);
                this.getContentPane().add(jLabel2,  null);
                this.getContentPane().add(jLabel3,  null);
                this.getContentPane().add(jLabel1,  null);
                this.getContentPane().add(jButton1,  null);
                this.getContentPane().add(view1,  null);
                this.getContentPane().add(view2,  null);
        }
        //  按下Update按钮，通知Model数据发生改变.
        void  jButton1_actionPerformed(ActionEvent  e)
        {
                Data[]  data  =  new  Data[2];
                data[0]  =  new  Data();
                data[1]  =  new  Data();
                data[0].name  =  jLabel1.getText();
                data[0].value  =  Integer.parseInt(jTextField1.getText());
                data[1].name  =  jLabel2.getText();
                data[1].value  =  Integer.parseInt(jTextField2.getText());
                Model  m  =  new  Model(data);
                this.model.changeModel(m);
        }
        public  static  void  main(String[]  args)
        {
                Controller  c  =  new  Controller();
                c.setSize(475,310);
                c.setVisible(true);
        }
}

运行程序

各位可以将这些代码各自存为相应的源文件，执行以下命令编译
javac  Controller.java
运行
java  Controller.class
就可以看到程序执行的效果，

你可以试着改变两个学生的年龄，按一下Update按钮，相应的视图就更新了。怎么样，体验到了MVC结构给程序带来的方便性了吧?;

金家寶 2007-03-09 01:40 发表评论

spring hibernate struts整合开发实例

金家寶 — Thu, 08 Mar 2007 17:35:00 GMT

一，数据表（因为是一个小例子，所以只有一个表，毕竟这不是一个讲怎么配置hibernate级联的例子。）
CREATE TABLE `members` (
`id` int(7) NOT NULL auto_increment,
`name` varchar(20) NOT NULL default '',
`password` varchar(20) default NULL,
`sex` varchar(10) default NULL,
`mail` varchar(50) default NULL,
PRIMARY KEY (`id`),
UNIQUE KEY `name` (`name`)
) ENGINE=MyISAM AUTO_INCREMENT=4 DEFAULT CHARSET=utf8
二，hibernate持久化类及映射文件、数据库操作封装DAO
package com.yang.product.booksonline.dao;

/**
* Members
*/

public class Members implements java.io.Serializable {

// Fields

private Integer id;
private String name;
private String password;
private String sex;
private String mail;

// Constructors

/** default constructor */
public Members() {
}

/** minimal constructor */
public Members(String name) {
this.name = name;
}

/** full constructor */
public Members(String name, String password, String sex, String mail) {
this.name = name;
this.password = password;
this.sex = sex;
this.mail = mail;
}

// Property accessors

public Integer getId() {
return this.id;
}

public void setId(Integer id) {
this.id = id;
}

public String getName() {
return this.name;
}

public void setName(String name) {
this.name = name;
}

public String getPassword() {
return this.password;
}

public void setPassword(String password) {
this.password = password;
}

public String getSex() {
return this.sex;
}

public void setSex(String sex) {
this.sex = sex;
}

public String getMail() {
return this.mail;
}

public void setMail(String mail) {
this.mail = mail;
}
}

"http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">

package com.yang.product.booksonline.dao;

import java.util.List;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.hibernate.LockMode;
import org.hibernate.criterion.Example;
import org.springframework.context.ApplicationContext;
import org.springframework.orm.hibernate3.support.HibernateDaoSupport;

/**
* Data access object (DAO) for domain model class Members.
* @see com.yang.product.booksonline.dao.Members
* @author lanxincao
*/
public class MembersDAO extends HibernateDaoSupport {

private static final Log log = LogFactory.getLog(MembersDAO.class);

protected void initDao() {
//do nothing
}

public void save(Members transientInstance) {
log.debug("saving Members instance");
try {
getHibernateTemplate().saveOrUpdate(transientInstance);
log.debug("save successful");
} catch (RuntimeException re) {
log.error("save failed", re);
throw re;
}
}

public void delete(Members persistentInstance) {
log.debug("deleting Members instance");
try {
getHibernateTemplate().delete(persistentInstance);
log.debug("delete successful");
} catch (RuntimeException re) {
log.error("delete failed", re);
throw re;
}
}

public Members findById( java.lang.Integer id) {
log.debug("getting Members instance with id: " + id);
try {
Members instance = (Members) getHibernateTemplate()
.get("com.yang.product.booksonline.dao.Members", id);
return instance;
} catch (RuntimeException re) {
log.error("get failed", re);
throw re;
}
}

public List findByExample(Members instance) {
log.debug("finding Members instance by example");
try {
List results = getSession()
.createCriteria("com.yang.product.booksonline.dao.Members")
.add(Example.create(instance))
.list();
log.debug("find by example successful, result size: " + results.size());
return results;
} catch (RuntimeException re) {
log.error("find by example failed", re);
throw re;
}
}

public Members merge(Members detachedInstance) {
log.debug("merging Members instance");
try {
Members result = (Members) getHibernateTemplate()
.merge(detachedInstance);
log.debug("merge successful");
return result;
} catch (RuntimeException re) {
log.error("merge failed", re);
throw re;
}
}

public void attachDirty(Members instance) {
log.debug("attaching dirty Members instance");
try {
getHibernateTemplate().saveOrUpdate(instance);
log.debug("attach successful");
} catch (RuntimeException re) {
log.error("attach failed", re);
throw re;
}
}

public void attachClean(Members instance) {
log.debug("attaching clean Members instance");
try {
getHibernateTemplate().lock(instance, LockMode.NONE);
log.debug("attach successful");
} catch (RuntimeException re) {
log.error("attach failed", re);
throw re;
}
}

public List findByMembersName(String name){
log.debug("finding by members' name.");
try {
return getHibernateTemplate().find("from Members as members where members.name = ?"
,new String[]{name});
} catch (RuntimeException re) {
log.error("finding by members' name failed",re);
throw re;
}
}

public static MembersDAO getFromApplicationContext(ApplicationContext ctx) {
return (MembersDAO) ctx.getBean("MembersDAO");
}
}

三，spring配置

http://www.springframework.org/dtd/spring-beans.dtd">

com.mysql.jdbc.Driver

jdbc:mysql://localhost:3306/books

root

snrdcqmq

org.hibernate.dialect.MySQLDialect

com/yang/product/booksonline/dao/Members.hbm.xml

四，struts配置及action类

http://struts.apache.org/dtds/struts-config_1_2.dtd">

attribute="membersForm"
name="membersForm"
parameter="action"
path="/members"
scope="request"
type="org.springframework.web.struts.DelegatingActionProxy" >

package com.yang.product.booksonline.action;

import java.util.List;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.apache.struts.action.ActionForm;
import org.apache.struts.action.ActionForward;
import org.apache.struts.action.ActionMapping;
import org.apache.struts.action.DynaActionForm;
import org.apache.struts.actions.DispatchAction;

import com.yang.product.booksonline.dao.Members;
import com.yang.product.booksonline.dao.MembersDAO;

/**
* XDoclet definition:
* @struts.action path="/members" name="membersForm" parameter="action" scope="request" validate="true"
*/
public class MembersAction extends DispatchAction {
private MembersDAO membersDAO;

public MembersDAO getMembersDAO() {
return membersDAO;
}

public void setMembersDAO(MembersDAO membersDAO) {
this.membersDAO = membersDAO;
}

public ActionForward login (ActionMapping mapping,ActionForm form,HttpServletRequest request,HttpServletResponse response) {
// String url = request.getParameter("url");
String name = (String)((DynaActionForm)form).get("name");
String password = (String)((DynaActionForm)form).get("password");
List members = membersDAO.findByMembersName(name);
if (members != null && members.size() >0) {
Members member = (Members)members.get(0);
if (password.equals(member.getPassword())) {
request.getSession().setAttribute("member",name);
//return new ActionForward(url);
return mapping.findForward("loginSuccess");
} else {
return null;
}
} else {
return null;
}
}

public ActionForward logout (ActionMapping mapping,ActionForm form,HttpServletRequest request,HttpServletResponse response) {
request.getSession().removeAttribute("member");
return mapping.findForward("logoutSuccess");
}

public ActionForward register (ActionMapping mapping,ActionForm form,HttpServletRequest request,HttpServletResponse response) {
String name = (String)((DynaActionForm)form).get("name");
String password = (String)((DynaActionForm)form).get("password");
String sex = (String)((DynaActionForm)form).get("sex");
String mail = (String)((DynaActionForm)form).get("mail");
List members = membersDAO.findByMembersName(name);
if (members != null && members.size() >0) {
return null;
} else {
Members member = new Members();
member.setName(name);
member.setPassword(password);
member.setSex(sex);
member.setMail(mail);
membersDAO.save(member);
return mapping.findForward("registerSuccess");
}
}
}

注意到，这里使用了dispatchaction。
五，三个jsp部分内容
index.jsp

Welcome,you have not login.

Welcome,.Logout

login.jsp

If you haven't registered the system,please register

:
:

register.jsp

Welcome to register the books online.

:

:

:

:

注意：在开发过程中，本想加上输入验证的，因为前面己经有了这方面的例子，为了不重复，这里就有意去掉了这部分，但要运行这个例子，还是你自己加上validation.xml、validator-rules.xml两个文件，不然会出错。

金家寶 2007-03-09 01:35 发表评论