2011年5月30日随笔档案 - 壹咪阳光

2011年5月30日

摘要: JSF学习笔记 JSF事件驱动型的MVC框架,与流行的struts比较学习，易于理解。jsf component event事件是指从浏览器由用户操作触发的事件，Struts application event 是用Action来接受浏览器表单提交的事件，一个表单只能对应一个事件，application event和component event相比是一种粗粒度的事件。优点：事件... 阅读全文

posted @ 2011-05-30 21:48 junly 阅读(1243) | 评论 (2) | 编辑收藏

Struts2 自定义标签的方法

Struts2 的UITag原理：
Struts2 UITag分三部份组成，一部份用于定义Tag的内容与逻辑的UIBean，一部份用于定义JSP Tag，也就是平时我们定义的那种，最后就是Template，它存放在你的theme目录之下，是一个FreeMarker模板文件。

我现在辑写一份MMTag，它主要是用于输出带链接的文字，比如像这样：
<cur:mm message="'I am a boy.'" />
就会输出：
<a href="http://www.blogjava.net/natlive">I am boy.</a>

我们先写UIBean部份：我们把它定义为MM，它继承于 org.apache.struts2.components.UIBean：

package limitstudy.corestruts2.tag;

import org.apache.struts2.components.UIBean;
import org.apache.struts2.views.annotations.StrutsTag;
import org.apache.struts2.views.annotations.StrutsTagAttribute;
import com.opensymphony.xwork2.util.ValueStack;

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

@StrutsTag(name="mm", tldTagClass="limitstudy.corestruts2.tag.MMTag", description="MM")
public class MM extends UIBean {
    private String message;

    public MM(ValueStack stack, HttpServletRequest request, HttpServletResponse response) {
        super(stack, request, response);
    }

    @Override
    protected String getDefaultTemplate() {
        return "mm";
    }

    @StrutsTagAttribute(description="set message", type="String")
    public void setMessage(String message) {
        this.message = message;
    }

    @Override
    protected void evaluateExtraParams() {
        super.evaluateExtraParams();

        if (null != message) {
            addParameter("message", findString(message));
        }
    }
}

* strutsTag注解指明了该UIBean的名字和Tag类的类名。
* getDefaultTemplate()方法用于返回模板的名字，Struts2会自动在后面加入.ftl扩展名以找到特定的模板文件。
* setXXX，设置UIBean的属性，一般Tag中有几个这样的属性，这里就有几个。@StrutsTagAttribute(description="set message", type="String") 注解，说明该属性是字符串（也可以是其它），这一步很重要。
* 覆写evaluateExtraParams（）方法，在UIBean初始化后会调用这个方法来初始化设定参数，如addParameter方法，会在freemarker里的parameters里加入一个key value。这里要注意findString，还有相关的findxxxx方法，它们是已经封装好了的解释ognl语法的工具，具体是怎么样的，大家可以查看一下UIBean的api doc。

然后是Tag部份：

package limitstudy.corestruts2.tag;

import org.apache.struts2.views.jsp.ui.AbstractUITag;
import org.apache.struts2.components.Component;
import com.opensymphony.xwork2.util.ValueStack;

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

public class MMTag extends AbstractUITag {
    private String message;

    @Override
    public Component getBean(ValueStack stack, HttpServletRequest request, HttpServletResponse response) {
        return new MM(stack, request, response);
    }

    @Override
    protected void populateParams() {
        super.populateParams();

        MM mm = (MM)component;
        mm.setMessage(message);
    }

    public void setMessage(String message) {
        this.message = message;
    }
}

* getBean（）返回该Tag中的UIBean。
* populateParams()初始化参数，一般用来初始化UIBean(Component)。
* setXXXX设置属性，和jsp tag是一样的。

在/WEB-INF/tlds/下建立current.tld文件（文名随你喜欢）：

<?xml version="1.0" encoding="UTF-8"?>
<taglib xmlns="http://java.sun.com/xml/ns/j2ee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" version="2.0"
        xsi:schemaLocation="http://java.sun.com/xml/ns/j2ee http://java.sun.com/xml/ns/j2ee/web-jsptaglibrary_2_0.xsd">
    <description>test</description>
    <tlib-version>2.0</tlib-version>
    <short-name>cur</short-name>
    <uri>/cur</uri>

    <tag>
        <name>mm</name>
        <tag-class>limitstudy.corestruts2.tag.MMTag</tag-class>
        <body-content>JSP</body-content>
        <attribute>
            <name>message</name>
            <required>true</required>
        </attribute>
    </tag>
</taglib>

在源代码目录中建立template/simple目录（这个目录名和你的theme有关），然后在里面建一个 mm.ftl文件：

<a href="http://www.yinsha.com">${parameters.message?html}</a>

建一个action测试一下，视图文件：

<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<%@ taglib prefix="s" uri="/struts-tags" %>
<%@ taglib prefix="cur" uri="/cur" %>
<html>
<head>
<title><s:property value="message" /></title>
</head>
<body>
<cur:mm message="haoahahhahaha" />
</body>
</html>

完。

PS：写得有些粗鄙，所以，如有问题的，可以留言。

http://devilkirin.javaeye.com/blog/427395

http://xiaojianhx.javaeye.com/blog/482888

posted @ 2011-05-30 21:43 junly 阅读(1101) | 评论 (1) | 编辑收藏

Useing Jquery With JSF

Page

The following is register.jsp, which takes required information from user regarding registration. For this example, we focus only on validation of username and not the actual registration process.

The most important thing is to know how to access JSF component from JQuery. The id given to inputText is consisting of formid:componentid. So in this example the id given to textbox is registerform:username. But the presence of : (colon) causes problem to JQuery. So, we need to escape : (colon) using two \\ characters before colon - registerform\\:username.

//register.jsp
<%@page contentType="text/html" %>de">

<%@page contentType="text/html" %>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"
    "http://www.w3.org/TR/html4/loose.dtd">
<html>
    <head>
        <script language="javascript" src="jquery-1.4.2.js"></script>
        <script language="javascript">
            function checkUsername(){
                $.get( "checkusername.jsp",{username : $("#registerform\\:username").val()},updateUsername);
            }
            function updateUsername(response)
            {
                if (response) {
                    $("#usernameresult").text(response);  // update SPAN item with result
            }
        </script>
        <title>Registration</title>
    </head>
    <body>
        <%@taglib prefix="f" uri="http://java.sun.com/jsf/core"%>
        <%@taglib prefix="h" uri="http://java.sun.com/jsf/html"%>
        <f:view>
           <h2>Registration </h2>
           <h:form  id="registerform">
           <table>
                    <tr>
                        <td>Username : </td>
                        <td><h:inputText id="username" value="#{userBean.username}"  required="true" onblur="checkUsername()" />
                            <h:message for="username" />
                            <span id="usernameresult" />
                    </tr>
                    <tr>
                        <td>Password : </td>
                        <td><h:inputSecret id="password" value="#{userBean.password}"  required="true" /> <h:message for="password" /> </td>
                    </tr>
                    <tr>
                        <td>Re-enter Password : </td>
                        <td><h:inputSecret id="confirmPwd" value="#{userBean.confirmPwd}"  required="true" /> <h:message for="confirmPwd" /> </td>
                    </tr>
                    <tr>
                        <td>Email Address  : </td>
                        <td><h:inputText id="email" value="#{userBean.email}" required="true" onblur="checkEmail()"  /> <h:message for="email" /> </td>
                            <span id="emailresult" />
                    </tr>
               </table>

              <p/>
              <h:commandButton actionListener="#{userBean.register}" value="Register" />
              <p/>
              <h3><h:outputText value="#{userBean.message}" escape="false"  /> </h3>
              <p/>
           </h:form>
        </f:view>
    </body>
</html>lt;/f:view>
    </body>
</html>

Bean

The above JSF Form uses userBean, which is the name given to beans.UserBean class. The class and its entries in faces-config.xml file are given below.

UserBean is the managed bean that stores data coming from JSF form. It contains an action listener - register(), which is supposed to process the data to complete registration process. We don't deal with it as our focus is only on validating username.

//UserBean.java
package beans;

public class UserBean {
    private String username, password, email,confirmPwd, message;

    public UserBean() {
    }

    public String getPassword() {
        return password;
    }

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

    public String getUsername() {
        return username;
    }

    public void setUsername(String username) {
        this.username = username;
    }

    public String getConfirmPwd() {
        return confirmPwd;
    }

    public void setConfirmPwd(String confirmPwd) {
        this.confirmPwd = confirmPwd;
    }

    public String getEmail() {
        return email;
    }

    public void setEmail(String email) {
        this.email = email;
    }

    public String getMessage() {
        return message;
    }

    public void setMessage(String message) {
        this.message = message;
    }

    public void  register(ActionEvent evt) {
       if (! password.equals(confirmPwd))
       {
             message = "Password do not match!";
             return;
       }
       // do registration
    } // register
}

xml

The following entry is required in faces-config.xml for UserBean managed bean.

<managed-bean>
        <managed-bean-name>userBean</managed-bean-name>
        <managed-bean-class>beans.UserBean</managed-bean-class>
        <managed-bean-scope>request</managed-bean-scope>
</managed-bean>

Check

Now create a checkusername.jsp to check whether given username is valid. It sends a message if username is already exists otherwise it sends empty string (nothing).

<%@ page import="java.sql.*"  contentType="text/plain"%>
<%
String username = request.getParameter("username");  // sent from client
// connect to oracle using thin driver
Class.forName("oracle.jdbc.driver.OracleDriver");
Connection con = DriverManager.getConnection("jdbc:oracle:thin:@localhost:1521:xe","youruser","yourpassword");
PreparedStatement ps = con.prepareStatement("select username from users where username = ?");
ps.setString(1,username);
ResultSet  rs = ps.executeQuery();
if ( rs.next()) { // found username
    out.println("Username is already present!");  // send this to client
}
rs.close();
ps.close();
con.close();
%>

Deploy and Test

Now deploy the web application and run register.jsp. If you enter a username that is already present in USERS table then we get message - Username is already present - in SPAN item on the right of username field. If username is unique then SPAN item is set to empty string ( as JSP returns nothing).

from:http://www.srikanthtechnologies.com/blog/java/jquerywithjsf.aspx

posted @ 2011-05-30 21:38 junly 阅读(754) | 评论 (0) | 编辑收藏

Page

Bean

xml

Check

Deploy and Test

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