Ant unless 和condition的用法

比眉伴天荒 2022-07-28 09:52 180阅读 0赞

我们先看这个build.xml， 有三个target，其中dist默认会调用conditionOne的if部分。ifTarget默认因为有if="conditionOne"，如果不**设置**conditionOne属性就不执行。 elseTarget部分因为unless="conditionOne"， 默认执行echo，除非设置conditionOne属性

<project name="testAntCondition">    
    <target name="dist">  
       <echo>is dist target sart</echo>       
        <condition property="conditionOne">    
            <istrue value="true"/>    
        </condition>  
        <antcall target="ifTarget">    
        </antcall>  
        <antcall target="elseTarget">    
        </antcall>  
  
        <echo>is dist target end</echo>           
    </target>    
    <target name="ifTarget" if="conditionOne">    
        <echo>is if part</echo>    
    </target>    
    <target name="elseTarget" unless="conditionOne">    
        <echo>is else part</echo>    
    </target>    
</project>

其中dist默认会调用conditionOne的if部分

F:\\>ant dist  
Buildfile: F:\\build.xml  
  
dist:  
     \[echo\] is dist target sart  
  
ifTarget:  
     \[echo\] is if part  
  
elseTarget:  
     \[echo\] is dist target end  
  
BUILD SUCCESSFUL  
Total time: 0 seconds

**ifTarget默认因为有if="conditionOne"，如果不设置conditionOne属性就不执行。**  
F:\\>ant ifTarget  
Buildfile: F:\\build.xml  
  
ifTarget:  
  
BUILD SUCCESSFUL  
Total time: 0 seconds  
  
F:\\>ant ifTarget -DconditionOne=yes  
Buildfile: F:\\build.xml  
  
ifTarget:  
     \[echo\] is if part  
  
BUILD SUCCESSFUL  
Total time: 0 seconds  
  
elseTarget部分因为unless="conditionOne"， 默认执行echo，除非设置conditionOne属性  
F:\\>ant elseTarget  
Buildfile: F:\\build.xml  
  
elseTarget:  
     \[echo\] is else part  
  
BUILD SUCCESSFUL  
Total time: 0 seconds  
  
F:\\>ant elseTarget -DconditionOne=no  
Buildfile: F:\\build.xml  
  
elseTarget:  
  
BUILD SUCCESSFUL  
Total time: 0 seconds

**dist不接受设置的conditionOne属性**

F:\\>ant dist -DconditionOne=yes  
Buildfile: F:\\build.xml  
  
dist:  
     \[echo\] is dist target sart  
  
ifTarget:  
     \[echo\] is if part  
  
elseTarget:  
     \[echo\] is dist target end  
  
BUILD SUCCESSFUL  
Total time: 0 seconds  
  
F:\\>ant dist -DconditionOne=no  
Buildfile: F:\\build.xml  
  
dist:  
     \[echo\] is dist target sart  
  
ifTarget:  
     \[echo\] is if part  
  
elseTarget:  
     \[echo\] is dist target end  
  
BUILD SUCCESSFUL  
Total time: 0 seconds

看执行效果

![Center][]

https://ant.apache.org/manual/

Ant官方手册

<table> 
 <tbody> 
  <tr> 
   <td>if</td> 
   <td>the name of the property that must be set in order for this target to execute, or<a href="http://ant.apache.org/manual/properties.html#if+unless" rel="nofollow">something evaluating to true</a>.</td> 
   <td align="center">No</td> 
  </tr> 
  <tr> 
   <td>unless</td> 
   <td>the name of the property that must not be set in order for this target to execute, or<a href="http://ant.apache.org/manual/properties.html#if+unless" rel="nofollow">something evaluating to false</a>.</td> 
   <td align="center">No</td> 
  </tr> 
 </tbody> 
</table>

[Center]: /images/20220724/f324b234ac31418a865b8b14bf24ab97.png