这可以分两步完成:

对于每个源目录，您应该创建自己的模块。 在所有模块中，您应该指定相同的构建目录:${build.directory}

如果你使用已启动的Jetty (Jetty:run)，那么重新编译任何模块中的任何类(使用Maven、IDEA或Eclipse)都会导致Jetty重新启动。对于修改后的资源，您将获得相同的行为。

你可以用build-helper添加一个新的源目录:

<build>
    <plugins>
        <plugin>
            <groupId>org.codehaus.mojo</groupId>
            <artifactId>build-helper-maven-plugin</artifactId>
            <version>3.2.0</version>
            <executions>
                <execution>
                    <phase>generate-sources</phase>
                    <goals>
                        <goal>add-source</goal>
                    </goals>
                    <configuration>
                        <sources>
                            <source>src/main/generated</source>
                        </sources>
                    </configuration>
                </execution>
            </executions>
        </plugin>
    </plugins>
</build>

这对我很有效

<build>
    <sourceDirectory>.</sourceDirectory>
    <plugins>
        <plugin>
        <groupId>org.apache.maven.plugins</groupId>
        <artifactId>maven-compiler-plugin</artifactId>
        <configuration>
        <includes>
            <include>src/main/java/**/*.java</include>
            <include>src/main2/java/**/*.java</include>
        </includes>
        </configuration>
        </plugin>
    </plugins>
</build>

这适用于maven 3.5.4，现在Intellij Idea将此代码视为源代码:

<plugin>
     <groupId>org.apache.maven.plugins</groupId>
     <artifactId>maven-compiler-plugin</artifactId>
     <version>3.3</version>
     <configuration>
         <generatedSourcesDirectory>src/main/generated</generatedSourcesDirectory>                    
     </configuration>
</plugin>

为了让它在intelliJ中工作，你还可以通过这种方式将generatedSourcesDirectory添加到编译器插件:

<plugin>
    <groupId>org.apache.maven.plugins</groupId>
    <artifactId>maven-compiler-plugin</artifactId>
    <version>3.8.1</version>
    <configuration>
        <generatedSourcesDirectory>src/main/generated</generatedSourcesDirectory>
    </configuration>
</plugin>

在配置中，您可以使用<compileSourceRoots>。

oal:          org.apache.maven.plugins:maven-compiler-plugin:3.8.1:compile (default-cli)
[DEBUG] Style:         Regular
[DEBUG] Configuration: <?xml version="1.0" encoding="UTF-8"?>
<configuration>
  <basedir default-value="${basedir}"/>
  <buildDirectory default-value="${project.build.directory}"/>
  <compilePath default-value="${project.compileClasspathElements}"/>
  <compileSourceRoots default-value="${project.compileSourceRoots}"/>
  <compilerId default-value="javac">${maven.compiler.compilerId}</compilerId>
  <compilerReuseStrategy default-value="${reuseCreated}">${maven.compiler.compilerReuseStrategy}</compilerReuseStrategy>
  <compilerVersion>${maven.compiler.compilerVersion}</compilerVersion>
  <debug default-value="true">${maven.compiler.debug}</debug>
  <debuglevel>${maven.compiler.debuglevel}</debuglevel>
  <encoding default-value="${project.build.sourceEncoding}">${encoding}</encoding>
  <executable>${maven.compiler.executable}</executable>
  <failOnError default-value="true">${maven.compiler.failOnError}</failOnError>
  <failOnWarning default-value="false">${maven.compiler.failOnWarning}</failOnWarning>
  <forceJavacCompilerUse default-value="false">${maven.compiler.forceJavacCompilerUse}</forceJavacCompilerUse>
  <fork default-value="false">${maven.compiler.fork}</fork>
  <generatedSourcesDirectory default-value="${project.build.directory}/generated-sources/annotations"/>
  <maxmem>${maven.compiler.maxmem}</maxmem>
  <meminitial>${maven.compiler.meminitial}</meminitial>
  <mojoExecution default-value="${mojoExecution}"/>
  <optimize default-value="false">${maven.compiler.optimize}</optimize>
  <outputDirectory default-value="${project.build.outputDirectory}"/>
  <parameters default-value="false">${maven.compiler.parameters}</parameters>
  <project default-value="${project}"/>
  <projectArtifact default-value="${project.artifact}"/>
  <release>${maven.compiler.release}</release>
  <session default-value="${session}"/>
  <showDeprecation default-value="false">${maven.compiler.showDeprecation}</showDeprecation>
  <showWarnings default-value="false">${maven.compiler.showWarnings}</showWarnings>
  <skipMain>${maven.main.skip}</skipMain>
  <skipMultiThreadWarning default-value="false">${maven.compiler.skipMultiThreadWarning}</skipMultiThreadWarning>
  <source default-value="1.6">${maven.compiler.source}</source>
  <staleMillis default-value="0">${lastModGranularityMs}</staleMillis>
  <target default-value="1.6">${maven.compiler.target}</target>
  <useIncrementalCompilation default-value="true">${maven.compiler.useIncrementalCompilation}</useIncrementalCompilation>
  <verbose default-value="false">${maven.compiler.verbose}</verbose>
</configuration>

这些都是3.8.1版本的编译插件可用的所有配置。不同的版本有不同的配置，您可以通过在通用mvn命令后使用-X运行代码来找到这些配置。就像

mvn clean install -X
mvn compiler:compile -X

并搜索id或目标或插件名称 这可能对其他插件也有帮助。Eclipse、intelliJ可能不会显示所有配置作为建议。