ant 条件判断 condition

basic elements: istrue isfalse not and or xor available isset equals  filesmatch
    1、istrue isfalse:断言 真 假

	<!-- istrue isfalse:断言 真 假 -->
	<target name="test">
		<!-- 给scondition设定值，istrue，断言真-->
		<condition property="scondition">
			<!-- istrue设为false，所以将scondition设为false-->
			<istrue value="false" />
		</condition>
		<!-- 调用isTrue和isFalse这两个target-->
		<antcall target="isTrue">
		</antcall>
		<antcall target="isFalse">
		</antcall>
	</target>
	<!-- if条件判断，成立执行-->
	<target name="isTrue" if="scondition">
		<echo>is ture</echo>
	</target>
	<!-- unless条件判断，不成立时执行-->
	<target name="isFalse" unless="scondition">
		<echo>is false</echo>
	</target>

 

    2、逻辑运算
    2.1、not 逻辑非 

	<target name="test4">
		<condition property="scondition">
			<not>
				<istrue value="true" />
			</not>
		</condition>
		<antcall target="isTrue">
		</antcall>
		<antcall target="isFalse">
		</antcall>
	</target>

 
    2.2、and 逻辑与
    2.3、or 逻辑或 xor异或 (语法上与and类似)

	<!-- and,or中的条件相与，相或 -->
	<target name="test4">
		<condition property="scondition">
			<or>
				<istrue value="true" />
				<istrue value="false" />
			</or>
		</condition>
		<antcall target="isTrue">
		</antcall>
		<antcall target="isFalse">
		</antcall>
	</target>

 

    3、available 是否可用
<project name="testCondition">
    <path id="all.test.classes">        
         <pathelement location="bin"/>
     </path>
    <target name="test">
        <condition property="scondition">
            <!--在指定的classpath路径下是否存在资源 TestTest.class-->
            <available resource="TestTest.class">
                <classpath refid="all.test.classes" />       
            </available>
        </condition>
        <antcall target="isTrue"></antcall>
        <antcall target="isFalse"></antcall>       
    </target>
    <target name="isTrue" if="scondition">
        <echo>is ture</echo>
    </target>
    <target name="isFalse" unless="scondition">
        <echo>is false</echo>
    </target>
</project>

    4、isset 指定属性是否存在

    <property name="name" value="this is name"/>    
    <target name="test2">
        <condition property="scondition">
            <!--如果属性name不存在则返回false-->
            <isset property="name"/>
        </condition>
        <antcall target="isTrue"></antcall>
        <antcall target="isFalse"></antcall>       
    </target>

 
    5、equals 是否相等
<project name="testCondition">
    <!--属性也可以通过ant参数-D来设置-->
    <property name="name" value="this is name"/>   
    <target name="test">
        <condition property="scondition">
            <!--如果arg1的值与arg2的值相等返回true，否则为false-->
            <equals arg1="${name}" arg2="this is name"/>
        </condition>
        <antcall target="isTrue"></antcall>
        <antcall target="isFalse"></antcall>       
    </target>
    <target name="isTrue" if="scondition">
        <echo>is ture</echo>
    </target>
    <target name="isFalse" unless="scondition">
        <echo>is false</echo>
    </target>
</project>   
    6、filesmatch 比较文件
<project name="testCondition">       
    <target name="test">
        <condition property="scondition">
            <!--如果file1所代表的文件与file2所代表的文件相等返回true，否则为false-->
            <filesmatch file1="testfile1.txt" file2="testfile2.txt"/>
        </condition>
        <antcall target="isTrue"></antcall>
        <antcall target="isFalse"></antcall>       
    </target>
    <target name="isTrue" if="scondition">
        <echo>is ture</echo>
    </target>
    <target name="isFalse" unless="scondition">
        <echo>is false</echo>
    </target>
</project>   


更多内容可以参考:http://ant.apache.org/manual/CoreTasks/conditions.html