单点登录加验证码例子

     在部署cas登录过程中,可能会用到验证码功能,这里简要介绍一下加入验证码的过程.
1.   首先,我用的cas版本是3.4.6,验证码采用的是CAPTCHA,所需jar包可以google搜索,部署好cas后.在web-info目录下找到login-webflow.xml,打开,找到如下代码:
     <view-state id="viewLoginForm" view="casLoginView" model="credentials">
        <var name="credentials" class="org.jasig.cas.authentication.principal.UsernamePasswordCredentials" />
        <binder>
            <binding property="username" />
            <binding property="password" />
        </binder>
        <on-entry>
            <set name="viewScope.commandName" value="'credentials'" />
        </on-entry>
<transition on="submit" bind="true" validate="true" to="realSubmit">
            <set name="flowScope.credentials" value="credentials" />
            <evaluate expression="authenticationViaFormAction.doBind(flowRequestContext, flowScope.credentials)" />
        </transition>
</view-state>
此段代码的功能是绑定cas登录过程中的用户名和密码,再次我们修改如下:
      <view-state id="viewLoginForm" view="casLoginView" model="credentials">
        <var name="credentials" class="org.jasig.cas.authentication.principal.UsernamePasswordCredentials" />
        <binder>
            <binding property="username" />
            <binding property="password" />
        </binder>
        <on-entry>
            <set name="viewScope.commandName" value="'credentials'" />
        </on-entry>
<transition on="submit" bind="true" validate="true" to="yzmSubmit">
            <set name="flowScope.credentials" value="credentials" />
            <evaluate expression="authenticationViaFormAction.doBind(flowRequestContext, flowScope.credentials)" />
        </transition>
</view-state>
也就是说,只需要修改realSubmit为yzmSubmit即可.然后加入如下配置:
      <!--fan add start-->
<action-state id="yzmSubmit">
        <evaluate expression="yzmViaFormAction.submit(flowRequestContext)" />
<transition on="success" to="realSubmit" />
<transition on="error" to="viewLoginForm" />
</action-state>
<!--fan add end-->
此段配置是自定义的验证码验证器,用来验证你提交的验证码的正确性.
  2.在web-info下找到cas-servlet.xml,打开后,加入
<!--fan add start-->
<bean id="yzmViaFormAction" class="com.ivan.zhang.servlet.YzmAction"
/>
<!--fan add end-->此配置是注册自定义的验证码
  3.编写如下类:
package com.ivan.zhang.servlet;

import com.ivan.zhang.CaptchaServiceSingleton;
import com.octo.captcha.service.image.ImageCaptchaService;
import java.io.PrintStream;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpSession;
import org.jasig.cas.web.support.WebUtils;
import org.springframework.webflow.core.collection.ParameterMap;
import org.springframework.webflow.execution.RequestContext;

public class YzmAction
{
  public final String submit(RequestContext context)
    throws Exception
  {
    Boolean flag = Boolean.valueOf(false);
    System.out.println("YzmAction is submiting....................");
    String yzm = context.getRequestParameters().get("yzm");
    String captchaId = WebUtils.getHttpServletRequest(context).getSession().getId();
    flag = CaptchaServiceSingleton.getInstance().validateResponseForID(captchaId,
      yzm);
    if (flag.booleanValue()) {
      return "success";
    }
    return "error";
  }
}
其中,flag = CaptchaServiceSingleton.getInstance().validateResponseForID(captchaId,
      yzm);
此句话是为了验证提交的验证码和先前生成的验证码的正确性,以此作为验证结果跳转的依据.CaptchaServiceSingleton此类是自定义类,稍后会附加完整的类供下载调试.
4.打开web-info/view/jsp/default/ui/casLoginView.jsp,在密码下面加入<%--fan add start --%>
<img alt="yzm" src="captcha.jpg">
<spring:message code="screen.welcome.label.yzm.accesskey" var="yzmAccessKey" />
<form:input cssClass="required" cssErrorClass="error" id="yzm" size="25" tabindex="1" accesskey="${yzmAccessKey}" path="yzm" autocomplete="false" htmlEscape="true" />
<%--fan add end --%>
5. 最后一步则是注册验证码生成器,打开web.xml文件,加入
<servlet> 
        <servlet-name>jcaptcha</servlet-name> 
        <servlet-class>com.ivan.zhang.servlet.ImageCaptchaServlet</servlet-class> 
        <load-on-startup>0</load-on-startup> 
    </servlet>
<servlet-mapping> 
        <servlet-name>jcaptcha</servlet-name> 
        <url-pattern>/captcha.jpg</url-pattern> 
    </servlet-mapping>
ok,就这么简单.简单解释一下流程,web.xml中注册的类是用来调用自定义的验证码生成器,以便在显示登陆界面的时候绘制验证码图片,并在session中生成标志位并记录,当用户提交验证码和用户名密码时,会先走自定义的验证码验证器(此时会先验证验证码的正确性),如果正确,再走用户名和密码的验证,如果不正确,则直接跳转回登陆页面.yzm.jar是自定义的验证码生成器和验证类,直接打包好后放到web-info/lib下.
如有疑问,请留言
  

评论

11 楼 cfying 2016-12-20  

<form:form>表单里的》<form:input>与login-webflow.xml所配置对应的实体类的属性没有一一对应上，所以才报这个错误。

10 楼 农家书虫 2015-04-21  

这么久了，不知道群主那个包还在不？能不能把源码发一份给我参看下，小弟在此感激不尽呀......([e-mail])

9 楼 YY008871 2013-04-25  

楼下这个类怎么替换啊？都没有找到这个类

8 楼 youmonan 2012-06-20  

import javax.validation.constraints.NotNull;
import javax.validation.constraints.Size;

/**
* UsernamePasswordCredentials respresents the username and password that a user
* may provide in order to prove the authenticity of who they say they are.
*
* @author Scott Battaglia
* @version $Revision: 1.2 $ $Date: 2007/01/22 20:35:26 $
* @since 3.0
* <p>
* This is a published and supported CAS Server 3 API.
* </p>
*/
public class UsernamePasswordCredentials implements Credentials {

    /** Unique ID for serialization. */
    private static final long serialVersionUID = -8343864967200862794L;

    /** The username. */
    @NotNull
    @Size(min=1,message = "required.username")
    private String username;

    /** The password. */
    @NotNull
    @Size(min=1, message = "required.password")
    private String password;
   
    private String yzm;

    public String getYzm() {
return yzm;
}

public void setYzm(String yzm) {
this.yzm = yzm;
}

/**
     * @return Returns the password.
     */
    public final String getPassword() {
        return this.password;
    }

    /**
     * @param password The password to set.
     */
    public final void setPassword(final String password) {
        this.password = password;
    }

    /**
     * @return Returns the userName.
     */
    public final String getUsername() {
        return this.username;
    }

    /**
     * @param userName The userName to set.
     */
    public final void setUsername(final String userName) {
        this.username = userName;
    }

    public String toString() {
        return "[username: " + this.username + "]";
    }

    @Override
    public boolean equals(final Object o) {
        if (this == o) return true;
        if (o == null || getClass() != o.getClass()) return false;

        UsernamePasswordCredentials that = (UsernamePasswordCredentials) o;

        if (password != null ? !password.equals(that.password) : that.password != null) return false;
        if (username != null ? !username.equals(that.username) : that.username != null) return false;
        if (yzm != null ? !yzm.equals(that.yzm) : that.yzm != null) return false;

        return true;
    }

    @Override
    public int hashCode() {
        int result = username != null ? username.hashCode() : 0;
        result = 31 * result + (password != null ? password.hashCode() : 0);
        return result;
    }
}
//将这个类替换

7 楼 youmonan 2012-06-19  

二楼怎么解决的啊

6 楼 youmonan 2012-06-19  

一楼怎么解决的啊

5 楼 youmonan 2012-06-19  

javax.servlet.jsp.JspTagException: No message found under code 'screen.welcome.label.yzm.accesskey' for locale 'zh_CN'

这个怎么解决啊！求帮助。

4 楼 xqhong110 2012-03-16  

ognl.NoSuchPropertyException: org.jasig.cas.authentication.principal.UsernamePasswordCredentials.yzm

报这个错！

3 楼 binghejinjun 2011-11-22  

恩,你暂时把<spring:message code="screen.welcome.label.yzm.accesskey" var="yzmAccessKey" />
去掉

2 楼 qq361961 2011-11-15  

1楼的错误解决了.
在cas 服务端 messages.properties 加入相关配置.

但之后又报错
ERROR [org.springframework.web.servlet.tags.form.InputTag] - <Property not found>
org.springframework.binding.expression.PropertyNotFoundException: Property not found

严重: Servlet.service() for servlet jsp threw exception
ognl.NoSuchPropertyException: org.jasig.cas.authentication.principal.UsernamePasswordCredentials.yzm

1 楼 qq361961 2011-11-15  

报错
javax.servlet.jsp.JspTagException: No message found under code 'screen.welcome.label.yzm.accesskey' for locale 'zh_CN'.