JavaEE5学习笔记12JSF集成AJAX使用经验总结

1、JavaEE5学习笔记12-JSF集成AJAX使用经验总结刘岩JSF也支持AJAX，ajax4jsf是专门为JSF提供的AJAX框架。他的工作原理就是在客户端加载一个AJAX引擎，在这个引擎之上是呈现给用户的JSF页面，引擎之下就是JSF框架，也就是正常的JSF生命周期。换句话说页面上的组件一旦配置了ajax4jsf标签，那么该组件的JSF生命周期一直生活在ajax4jsf的阴影之下。用了ajax4jsf，开发者可以不用像以往的JSP页面那样，写js脚本，页面html组件触发js事件后，进行ajax请求，而是像组件监听器一样，对组件的事件进行一个监听，触发事件后，开始ajax引擎预处理，之后再

2、走JSF生命周期。生命图形如下首先下载，从山寨网站JKL/Downloadajax4jsf111jar.htm可以下载其jar包。之后再下载通用的一些jar包commons-beanutils.jarcommons-collections.jarcommons-digester.jarcommons-logging.jarweb.xml内容加入Ajax4jsf Filterajax4jsfajax4jsfFaces ServletREQUESTFORWARDINCLUDE这里声明一个过滤器，对servler名称叫做Faces Servlet的请求进行过滤，Faces Servlet就是JSF的

3、。正是中的过滤器。使得ajax的filter将会作用于直接从客户端过来的request，通过forward过来的request，通过include过来的request。就是这样一个过滤器拦截了所有的JSF请求。使用AJAX功能的页面代码用户登录页面用户登录页面注意：1):使用ajax功能必须加入ajax4jsf标签声明2):声明一个ajax作用域在这个作用域范围内的组件都可以使用AJAX功能。3):对组件进行显示的ajax声明，告诉引擎，这个组件需要进行ajax引擎处理，引擎过后才能交给JSF生命周期4):ajax4jsf也有相应的组件，比如用ajax的方式输出一个图形容器托管Bean如下/*

4、 * ClassName: UserBean.java * created on Nov 1, 2007 * Copyrights 2007-2008 qjyong All rights reserved. * EMail: */package ajax;import java.awt.Graphics2D;import java.awt.image.BufferedImage;import java.io.IOException;import java.io.OutputStream;import java.util.Random;import javax.faces.context.Fac

5、esContext;import javax.faces.event.ActionEvent;import javax.imageio.ImageIO;import javax.servlet.http.HttpSession;/* * author qiujy * version 1.0 * */public class UserBean private String userName;private String password;private String code; /用户输入的验证码private String validUserMsg;private String validat

6、eCodeMsg;private String myname;public String getMyname() return myname;public void setMyname(String myname) this.myname = myname;/* * return the code */public String getCode() return code;/* * param code the code to set */public void setCode(String code) this.code = code;/* * return the validUserMsg

7、 */public String getValidUserMsg() return validUserMsg;/* * param validUserMsg the validUserMsg to set */public void setValidUserMsg(String validUserMsg) this.validUserMsg = validUserMsg;/* * return the userName */public String getUserName() return userName;/* * param userName the userName to set */

8、public void setUserName(String userName) this.userName = userName;/* * return the password */public String getPassword() return password;/* * param password the password to set */public void setPassword(String password) this.password = password;/* * return the validateCodeMsg */public String getVali

9、dateCodeMsg() return validateCodeMsg;/* * param validateCodeMsg the validateCodeMsg to set */public void setValidateCodeMsg(String validateCodeMsg) this.validateCodeMsg = validateCodeMsg;public void validateUserName(ActionEvent event)System.out.println(input name= + this.userName);if(!userName.match

10、es(w6,20)this.validUserMsg = 用户名不合法!;public void paint(OutputStream out, Object data) throws IOException if (data instanceof ImageData) ImageData imageData = (ImageData) data; / 生成一个在10009999之间的随机数 Random randomNumber = new Random(); String keyCode = randomNumber.nextInt(8999) + 1000 + ; /把产生的随机数保存到

11、session中 HttpSession session = (HttpSession)FacesContext.getCurrentInstance() .getExternalContext().getSession(true); session.setAttribute(keyCode, keyCode); /生成干扰线的随机数 int outPutLine = 0; outPutLine = randomNumber.nextInt(100); BufferedImage img = new BufferedImage(imageData.getWidth(), imageData.g

12、etHeight(), BufferedImage.TYPE_INT_RGB); Graphics2D g = img.createGraphics(); g.setBackground(imageData.getBackground(); g.setColor(imageData.getDrawColor(); g.setFont(imageData.getTextFont(); /画矩形 g.clearRect(0, 0, imageData.getWidth(), imageData.getHeight(); /画干扰线 g.drawLine(outPutLine, outPutLine

13、, imageData.getWidth() - outPutLine, imageData.getHeight() - outPutLine); /画产生的随机数 g.drawString(keyCode, 10, 16); g.dispose(); ImageIO.write(img, jpeg, out); public String login()System.out.println(user-code + this.getCode();/从session中取出验证码HttpSession session = (HttpSession)FacesContext.getCurrentIn

14、stance().getExternalContext().getSession(true);String keyCode = (String)session.getAttribute(keyCode);if(keyCode.equals(this.getCode()return success;elsethis.validateCodeMsg = 验证码不正确;return null;public void isHaveName(ActionEvent event)System.out.println(input myname = + this.myname);if(liuyan.equal

15、sIgnoreCase(myname)this.validUserMsg = 用户重复！;在此用到了一个辅助类/* * ClassName: ImageData.java * created on Nov 28, 2007 * Copyrights 2007-2008 qjyong All rights reserved. * EMail: */package ajax;import java.awt.Color;import java.awt.Font;/* * author qiujy * version 1.0 * */public class ImageData implements

16、java.io.Serializable private int width = 60;private int height = 20;private Color background = new Color(0 xDCDCDC);private Color drawColor = Color.black;private Font textFont = new Font(Times New Roman, Font.PLAIN, 18);/* * return the width */public int getWidth() return width;/* * param width the

17、width to set */public void setWidth(int width) this.width = width;/* * return the height */public int getHeight() return height;/* * param height the height to set */public void setHeight(int height) this.height = height;/* * return the background */public Color getBackground() return background;/*

18、* param background the background to set */public void setBackground(Color background) this.background = background;/* * return the drawColor */public Color getDrawColor() return drawColor;/* * param drawColor the drawColor to set */public void setDrawColor(Color drawColor) this.drawColor = drawColor;/* * return the textFont */public Font getTextFont() return textFont;/* * param textFont the textFont to set */public void setTextFont(Font textFont) this.textFont = textFont;这是用于图形显示的。显示效果如下输入不正确的信息，鼠标焦点