maven项目引用外部jar包

<build>
        <plugins>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-compiler-plugin</artifactId>
                <version>2.3.2</version>
                <configuration>
                    <source>1.8</source>
                    <target>1.8</target>
                    <encoding>utf-8</encoding>
                    <!--指定外部lib加载本地jar包-->
                    <compilerArguments>
                        <extdirs>${project.basedir}/src/main/webapp/WEB-INF/lib/</extdirs>
                    </compilerArguments>
                </configuration>
            </plugin>
        <plugins>
<build>