<build>
????<directory>${project.basedir}/target</directory>
????<outputDirectory>${project.build.directory}/classes</outputDirectory>
????<finalName>${project.artifactId}-${project.version}</finalName>
????<testOutputDirectory>${project.build.directory}/test-classes</testOutputDirectory>
????<sourceDirectory>${project.basedir}/src/main/java</sourceDirectory>
????<scriptSourceDirectory>${project.basedir}/src/main/scripts</scriptSourceDirectory>
????<testSourceDirectory>${project.basedir}/src/test/java</testSourceDirectory>
????<resources>
??????<resource>
????????<directory>${project.basedir}/src/main/resources</directory>
??????</resource>
????</resources>
????<testResources>
??????<testResource>
????????<directory>${project.basedir}/src/test/resources</directory>
??????</testResource>
????</testResources>

我注意到有個${project.basedir}，等等，這個值是在哪定義的呢，整個pom.xml中并沒有<properties>的定義，請問我如何知道project.basedir的值在哪個文件定義的