因为jdk版本和jetty版本相差太多会导致无法运行，所以当jdk版本很高的时候需要给jetty换一个高版本，这个时候写法就变了，如下

<?xml version="1.0" encoding="UTF-8"?>

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
  xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
  <modelVersion>4.0.0</modelVersion>

  <groupId>com.shuaichao</groupId>
  <artifactId>testWeb5</artifactId>
  <version>1.0-SNAPSHOT</version>
  <packaging>war</packaging>

  <name>testWeb5 Maven Webapp</name>
  <!-- FIXME change it to the project's website -->
  <url>http://www.example.com</url>

  <properties>
    <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
    <maven.compiler.source>11</maven.compiler.source>
    <maven.compiler.target>11</maven.compiler.target>
  </properties>

  <dependencies>
    <dependency>
      <groupId>junit</groupId>
      <artifactId>junit</artifactId>
      <version>4.12</version>
      <scope>test</scope>
    </dependency>
  </dependencies>

  <build>
    <finalName>testWeb5</finalName>
    <plugins>
<!--      <plugin>-->
<!--        <groupId>org.eclipse.jetty</groupId>-->
<!--        <artifactId>jetty-server</artifactId>-->
<!--        <configuration>-->
<!--          <webApp>-->
<!--            <contextPath>/testWeb5</contextPath>-->
<!--          </webApp>-->
<!--          <stopKey>webx</stopKey>-->
<!--          <stopPort>9999</stopPort>-->
<!--          <connectors>-->
<!--            <connector implementation="org.eclipse.jetty.server.nio.SelectChannelConnector">-->
<!--              <port>9090</port>-->
<!--              <maxIdleTime>60000</maxIdleTime>-->
<!--            </connector>-->
<!--          </connectors>-->
<!--          <requestLog implementation="org.eclipse.jetty.server.NCSARequestLog">-->
<!--            <filename>target/access.log</filename>-->
<!--            <retainDays>90</retainDays>-->
<!--            <append>false</append>-->
<!--            <extended>false</extended>-->
<!--            <logTimeZone>GMT+8:00</logTimeZone>-->
<!--          </requestLog>-->
<!--          <systemProperties>-->
<!--            <systemProperty>-->
<!--              <name>productionMode</name>-->
<!--              <value>11.0.6</value>-->
<!--            </systemProperty>-->
<!--          </systemProperties>-->
<!--        </configuration>-->
<!--      </plugin>-->
      <plugin>
        <groupId>org.eclipse.jetty</groupId>
        <artifactId>jetty-maven-plugin</artifactId>
        <version>11.0.6</version>

        <configuration>
          <webApp>
            <contextPath>/testWeb5</contextPath>
          </webApp>


<!--          <scanIntervalSeconds>-->
<!--            10-->
<!--          </scanIntervalSeconds>-->
<!--          <contextPath>/testWeb5</contextPath>-->
<!--          <connectors>-->
<!--            <connector implementation="org.mortbay.jetty.nio.SelectChannelConnector">-->
<!--              <port>9090</port>-->
<!--            </connector>-->
<!--          </connectors>-->
        </configuration>
      </plugin>
      <plugin>
        <groupId>org.apache.tomcat.maven</groupId>
        <artifactId>tomcat7-maven-plugin</artifactId>
        <version>2.2</version>
        <configuration>
          <port>8080</port>
          <path>/testWeb5</path>
          <uriEncoding>UTF-8</uriEncoding>
          <server>tomcat9</server>
        </configuration>
      </plugin>
    </plugins>
  </build>

</project>