JCaptcha4Struts2插件，图像未加载

Question

我对struts非常陌生，我正在开发一个使用captcha验证的应用程序。在对预先构建的captcha插件进行了研究之后，我决定使用JCaptcha4Struts2.。

很快我就遇到了一连串的麻烦。我解决了所有的问题，但我能解决这个问题。

我做了演示应用程序中给出的所有事情，但是在我的应用程序中，图像并没有正确显示。事实上，只有一个黑色的矩形出现。下面是我使用的一组库：

• commons-collection-3.1
• commons-io-2.2
• commons-lang3-3.1
• commons-logging-1.1.3
• commons-logging-api-1.1
• freemarker-2.3.19
• ognl-3.0.6
• struts2-core-2.3.16.1
• xwork-core-2.3.16.1
• javax.mail-1.5.1 odbc7
• javassist-3.11.10.GA
• commons-fileupload-1.3.1
• jcaptcha4struts2-2.0.2
• struts2-jquery-plugin-3.7.0
• jcaptcha-1.0
• jcaptcha-api-1.0
• 成像-01012005
• antlr-2.7.2

我使用的开发环境是: netbeans 8.0，jdk 1.8，java ee 7

请为struts2提供一些其他的captcha选项(考虑到我对struts非常陌生，项目的截止日期也不是很远)。

编辑:我读到了struts 2.3.16在成像方面有一些问题，所以我也尝试了Struts2.0.11库

JSP文件

<%@taglib prefix="jcaptcha"  uri="http://code.google.com/p/jcaptcha4struts2/taglib/2.0" %>
//some html code
    <s:form name="login" action="login" method="post">
         <s:textfield name="username" label="Username" size="20" autofocus="true" />
         <s:password name="password" label="Password" size="20" />
         <jcaptcha:image label="Enter the text" height="30" width="100"/>
         <s:submit name="submit" label="Submit" align="center" />
     </s:form>

struts.xml

<struts>
    <constant name="struts.devMode" value="true" />
    <constant name="struts.action.extension" value="," />

    <package name="default" extends="jcaptcha4struts2-default">
        <action name="login"
            class="UserLoginAction"
            method="execute">
        <interceptor-ref name="jcaptchaDefaultStack"/>
        <result name="success">/profile.jsp</result>
        <result name="input">/</result>
        <result name="login">index.jsp</result>
        <result name="error">/</result>
    </action>     

 </package>

</struts>

编辑2:我进一步尝试使用各种排列版本的库(大多数是最新版本)，现在我得到了异常。这是堆叠痕迹

2014-04-07 16:15:25,874 DEBUG org.apache.struts2.dispatcher.Dispatcher.debug:80 - Exception occurred during processing request: null
java.lang.reflect.InvocationTargetException
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:483)
    at com.opensymphony.xwork2.DefaultActionInvocation.invokeAction(DefaultActionInvocation.java:450)
    at com.opensymphony.xwork2.DefaultActionInvocation.invokeActionOnly(DefaultActionInvocation.java:289)
    at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:252)
    at org.apache.struts2.interceptor.DeprecationInterceptor.intercept(DeprecationInterceptor.java:41)
    at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:246)
    at org.apache.struts2.interceptor.debugging.DebuggingInterceptor.intercept(DebuggingInterceptor.java:256)
    at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:246)
    at com.opensymphony.xwork2.interceptor.DefaultWorkflowInterceptor.doIntercept(DefaultWorkflowInterceptor.java:167)
    at com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:98)
    at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:246)
    at com.opensymphony.xwork2.validator.ValidationInterceptor.doIntercept(ValidationInterceptor.java:265)
    at org.apache.struts2.interceptor.validation.AnnotationValidationInterceptor.doIntercept(AnnotationValidationInterceptor.java:68)
    at com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:98)
    at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:246)
    at com.opensymphony.xwork2.interceptor.ConversionErrorInterceptor.intercept(ConversionErrorInterceptor.java:138)
    at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:246)
    at com.opensymphony.xwork2.interceptor.ParametersInterceptor.doIntercept(ParametersInterceptor.java:249)
    at com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:98)
    at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:246)
    at com.opensymphony.xwork2.interceptor.ParametersInterceptor.doIntercept(ParametersInterceptor.java:249)
    at com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:98)
    at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:246)
    at com.opensymphony.xwork2.interceptor.StaticParametersInterceptor.intercept(StaticParametersInterceptor.java:191)
    at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:246)
    at org.apache.struts2.interceptor.MultiselectInterceptor.intercept(MultiselectInterceptor.java:73)
    at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:246)
    at org.apache.struts2.interceptor.CheckboxInterceptor.intercept(CheckboxInterceptor.java:91)
    at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:246)
    at org.apache.struts2.interceptor.FileUploadInterceptor.intercept(FileUploadInterceptor.java:252)
    at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:246)
    at com.opensymphony.xwork2.interceptor.ModelDrivenInterceptor.intercept(ModelDrivenInterceptor.java:100)
    at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:246)
    at com.opensymphony.xwork2.interceptor.ScopedModelDrivenInterceptor.intercept(ScopedModelDrivenInterceptor.java:141)
    at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:246)
    at com.opensymphony.xwork2.interceptor.ChainingInterceptor.intercept(ChainingInterceptor.java:145)
    at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:246)
    at com.opensymphony.xwork2.interceptor.PrepareInterceptor.doIntercept(PrepareInterceptor.java:171)
    at com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:98)
    at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:246)
    at com.opensymphony.xwork2.interceptor.I18nInterceptor.intercept(I18nInterceptor.java:139)
    at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:246)
    at org.apache.struts2.interceptor.ServletConfigInterceptor.intercept(ServletConfigInterceptor.java:164)
    at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:246)
    at com.opensymphony.xwork2.interceptor.AliasInterceptor.intercept(AliasInterceptor.java:193)
    at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:246)
    at com.opensymphony.xwork2.interceptor.ExceptionMappingInterceptor.intercept(ExceptionMappingInterceptor.java:189)
    at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:246)
    at org.apache.struts2.impl.StrutsActionProxy.execute(StrutsActionProxy.java:54)
    at org.apache.struts2.dispatcher.Dispatcher.serviceAction(Dispatcher.java:562)
    at org.apache.struts2.dispatcher.ng.ExecuteOperations.executeAction(ExecuteOperations.java:77)
    at org.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuteFilter.doFilter(StrutsPrepareAndExecuteFilter.java:99)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:239)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:219)
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:106)
    at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:503)
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:136)
    at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:74)
    at org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:610)
    at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:88)
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:516)
    at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1015)
    at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:652)
    at org.apache.coyote.http11.Http11NioProtocol$Http11ConnectionHandler.process(Http11NioProtocol.java:222)
    at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1575)
    at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.run(NioEndpoint.java:1533)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
    at java.lang.Thread.run(Thread.java:744)
Caused by: java.lang.NoSuchMethodError: com.jhlabs.image.WaterFilter.setAmplitude(D)V
    at com.octo.captcha.engine.image.gimpy.DefaultGimpyEngine.buildInitialFactories(DefaultGimpyEngine.java:59)
    at com.octo.captcha.engine.image.ListImageCaptchaEngine.<init>(ListImageCaptchaEngine.java:24)
    at com.octo.captcha.engine.image.gimpy.DefaultGimpyEngine.<init>(DefaultGimpyEngine.java:48)
    at com.octo.captcha.service.image.DefaultManageableImageCaptchaService.<init>(DefaultManageableImageCaptchaService.java:32)
    at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
    at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)
    at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
    at java.lang.reflect.Constructor.newInstance(Constructor.java:408)
    at java.lang.Class.newInstance(Class.java:433)
    at com.google.code.jcaptcha4struts2.core.beans.JC4S2Config.getDefaultImageCaptchaService(JC4S2Config.java:110)
    at com.google.code.jcaptcha4struts2.core.beans.JC4S2Config.getImageCaptchaService(JC4S2Config.java:82)
    at com.google.code.jcaptcha4struts2.core.actions.JCaptchaImageAction.getImageCaptchaService(JCaptchaImageAction.java:107)
    at com.google.code.jcaptcha4struts2.core.actions.JCaptchaImageAction.execute(JCaptchaImageAction.java:75)
    ... 73 more

Answer 1

这个JCaptcha库非常老，根据它们的代码存储库的状态，它是一个废弃的项目。这个库的问题在于它使用了非常特定的JH实验室图像滤波器版本来处理CAPTCHA图像失真，而这个版本不支持JDK1.8，它只支持1.6。

但是如果你和reCAPTCHA一起去的话，它就不会再困扰你了。我决定和大家分享我的发现。