蚂蚁'失败，除非'失败即使属性存在

Question

我有一个蚂蚁脚本失败，它不应该。

属性文件：

application.foo.name=foo 
application.foo.path=[path-to-foo] 
application.foo.file=foo.jar 
appName= 

代码：

<target name="deploy_app" description="Deploys app"> 
    <condition property="appSelected"> 
    <and> 
     <not> 
     <equals arg1="${appName}" arg2="" /> 
     </not> 
     <isset property="${appName}" /> 
    </and> 
    </condition> 

    <if> 
    <equals arg1="${appSelected}" arg2="true" /> 
    <then> 
    <!-- do nothing! --> 
    </then> 
    <else> 
    <input 
     message="Please enter application name:" 
     addproperty="newAppName" 
    /> 
    <var name="appName" value="${newAppName}" /> 
    </else> 
</if> 
    <antcall inheritAll="true" target="deploy" /> 
</target> 

<target name="deploy"> 
    <echo message="Deploying from property: application.${appName}.file" /> 
    <propertycopy silent="true" name="appFile" from="application.${appName}.file" /> 
    <propertycopy silent="true" name="appPath" from="application.${appName}.path" /> 
    <echo message="appFile: ${appFile}" /> 
    <fail unless="${appFile}" message="appfile: ${appFile} No application with the name ${appName} is defined in your properties file." /> 
</target> 

输出：

[echo] Deploying from property: application.foo.file 
[echo] appFile: foo.jar 
ERROR: The following error occurred while executing this line: 
appfile: foo.jar No application with the name foo is defined in your properties file. 

它甚至打印出属性的值，但是认为它不存在！

任何原因为什么？

Answer 1

命令的参数unless需要一个属性名称，而不是属性值！

修正版本：

<fail unless="appFile" message="No application with the name ${appName} is defined in your properties file." />