pom.xml中project.reporting.outputEncoding

参考文档位置：https://cwiki.apache.org/confluence/display/MAVENOLD/Reporting+Encoding+Configuration

Adding this element to the POM structure without breaking backward compatibility can only happen in a future version, yet to be defined (at least after Maven 3.0):

<project>

  ...

  <reporting>

    <outputEncoding>UTF-8</outputEncoding>

    ...

  </reporting>

  ...

</project>

---

For Maven 2.x, the value can be defined as an equivalent property:

<project>

  ...

  <properties>

    <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>

    ...

  </properties>

  ...

</project>

Thus plugins could immediately be modified to use ${project.reporting.outputEncoding} expression, whatever Maven version is used.