最近用 Maven tomcat 插件启动的时候,突然发现很多关于 tomcat 扫描注解时发现一些 jar 包内 meta-info.class 的注解无效的信息,一般提示是Invalid byte tag in constant pool: 19。

这是为啥呢?原来 meta-info.class 是为了 Java9 的模块化产生的一个文件,本身在 Java8 里也用不上。所以 tomcat 扫描虽然报错了,但是却不影响启动和服务。

但是每次启动,屏幕显示一大片 ERROR,也不好排查真正的问题啊。搜索了一下,原来 tomcat 早已升级支持了,只要指定足够高的 tomcat 版本就能避免报错了。

具体版本号如下:

  • trunk for 9.0.0.M18 onwards
  • 8.5.x for 8.5.12 onwards
  • 8.0.x for 8.0.42 onwards
  • 7.0.x for 7.0.76 onwards

那么怎么指定 tomcat7-maven-plugin 的 tomcat 版本呢?tomcat 官网当然有说明啦,照猫画虎如下:

<project>
   [...]
  <properties>
   <tomcat.version>7.0.76</tomcat.version>
   [...]
  </properties>
   [...]
  <build>
    <pluginManagement>
      <plugins>
        <plugin>
          <groupId>org.apache.tomcat.maven</groupId>
          <artifactId>tomcat7-maven-plugin</artifactId>
          <version>2.3-SNAPSHOT</version>
          <dependencies>
          <dependency>
            <groupId>org.apache.tomcat.embed</groupId>
            <artifactId>tomcat-embed-core</artifactId>
            <version>${tomcat.version}</version>
          </dependency>
          <dependency>
            <groupId>org.apache.tomcat</groupId>
            <artifactId>tomcat-util</artifactId>
            <version>${tomcat.version}</version>
          </dependency>
          <dependency>
            <groupId>org.apache.tomcat</groupId>
            <artifactId>tomcat-coyote</artifactId>
            <version>${tomcat.version}</version>
          </dependency>
          <dependency>
            <groupId>org.apache.tomcat</groupId>
            <artifactId>tomcat-api</artifactId>
            <version>${tomcat.version}</version>
          </dependency>

          <dependency>
            <groupId>org.apache.tomcat</groupId>
            <artifactId>tomcat-jdbc</artifactId>
            <version>${tomcat.version}</version>
          </dependency>

          <dependency>
            <groupId>org.apache.tomcat</groupId>
            <artifactId>tomcat-dbcp</artifactId>
            <version>${tomcat.version}</version>
          </dependency>

          <dependency>
            <groupId>org.apache.tomcat</groupId>
            <artifactId>tomcat-servlet-api</artifactId>
            <version>${tomcat.version}</version>
          </dependency>

          <dependency>
            <groupId>org.apache.tomcat</groupId>
            <artifactId>tomcat-jsp-api</artifactId>
            <version>${tomcat.version}</version>
          </dependency>

          <dependency>
            <groupId>org.apache.tomcat</groupId>
            <artifactId>tomcat-jasper</artifactId>
            <version>${tomcat.version}</version>
          </dependency>

          <dependency>
            <groupId>org.apache.tomcat</groupId>
            <artifactId>tomcat-jasper-el</artifactId>
            <version>${tomcat.version}</version>
          </dependency>

          <dependency>
            <groupId>org.apache.tomcat</groupId>
            <artifactId>tomcat-el-api</artifactId>
            <version>${tomcat.version}</version>
          </dependency>

          <dependency>
            <groupId>org.apache.tomcat</groupId>
            <artifactId>tomcat-catalina</artifactId>
            <version>${tomcat.version}</version>
          </dependency>

          <dependency>
            <groupId>org.apache.tomcat</groupId>
            <artifactId>tomcat-tribes</artifactId>
            <version>${tomcat.version}</version>
          </dependency>

          <dependency>
            <groupId>org.apache.tomcat</groupId>
            <artifactId>tomcat-catalina-ha</artifactId>
            <version>${tomcat.version}</version>
          </dependency>

          <dependency>
            <groupId>org.apache.tomcat</groupId>
            <artifactId>tomcat-annotations-api</artifactId>
            <version>${tomcat.version}</version>
          </dependency>

          <dependency>
            <groupId>org.apache.tomcat</groupId>
            <artifactId>tomcat-juli</artifactId>
            <version>${tomcat.version}</version>
          </dependency>

          <dependency>
            <groupId>org.apache.tomcat.embed</groupId>
            <artifactId>tomcat-embed-logging-juli</artifactId>
            <version>${tomcat.version}</version>
          </dependency>
          <dependency>
            <groupId>org.apache.tomcat.embed</groupId>
            <artifactId>tomcat-embed-logging-log4j</artifactId>
            <version>${tomcat.version}</version>
          </dependency>
          </dependencies>
        </plugin>
        [...]
      </plugins>
    </pluginManagement>
    [...]
  </build>
  [...]
</project>

再启动,是不是顿时世界都清爽了呢?