我得到了同样的错误。做了下面这些之后，它就消失了。

右键单击项目。 选择Maven >更新项目…

在我遇到类似问题的情况下，我没有使用Andrew的修复建议，而是在向pom.xml引入<pluginManagement>标记后就可以简单地工作了。看起来这个错误是由于缺少<pluginManagement>标记。因此，为了避免Eclipse中的异常，我们需要简单地将所有插件标记包含在<pluginManagement>标记中，如下所示:

<build>
    <pluginManagement>
        <plugins>
            <plugin> ... </plugin>
            <plugin> ... </plugin>
                  ....
        </plugins>
    </pluginManagement>
</build>

一旦这个结构就位，错误就消失了。

哪里可以找到WTP:

鼠标在pom.xml中的<插件>上，然后“发现新的m2e连接器”。

我安装了他们所有的默认检查和它的工作。

转到workspace/rtc-ws/.metadata/.plugins/org.eclipse.m2e.core/lifecycle-mapping-metadata.xml，然后创建lifecycle-mapping-metadata.xml文件，并按如下方式粘贴并重新加载配置

如果你正在使用Eclipse 4.2，在映射方面有问题，并且不想把乱七八糟的东西放到pom.xml中，创建一个新的文件Lifecycle -mapping-metadata.xml，在Windows中配置它-> Preferences -> Lifecycle mapping(不要忘记在每次更改这个文件后按Reload workspace Lifecycle mappings metadata !)下面是基于eclipse/plugins/org.eclipse.m2e.lifecyclemapping. defaults_3 .2.0.20120903-1050.jar/ lifeccycle -mapping-metadata.xml的示例

<?xml version="1.0" encoding="UTF-8"?>
<lifecycleMappingMetadata>
    <pluginExecutions>
        <pluginExecution>
            <pluginExecutionFilter>
                <groupId>org.codehaus.mojo</groupId>
                <artifactId>buildnumber-maven-plugin</artifactId>
                <goals>
                    <goal>create-timestamp</goal>
                </goals>
                <versionRange>[0.0,)</versionRange>
            </pluginExecutionFilter>
            <action>
                <ignore />
            </action>
        </pluginExecution>

        <pluginExecution>
            <pluginExecutionFilter>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-dependency-plugin</artifactId>
                <goals>
                    <goal>list</goal>
                </goals>
                <versionRange>[0.0,)</versionRange>
            </pluginExecutionFilter>
            <action>
                <ignore />
            </action>
        </pluginExecution>

        <pluginExecution>
            <pluginExecutionFilter>
                <groupId>org.zeroturnaround</groupId>
                <artifactId>jrebel-maven-plugin</artifactId>
                <goals>
                    <goal>generate</goal>
                </goals>
                <versionRange>[0.0,)</versionRange>
            </pluginExecutionFilter>
            <action>
                <ignore />
            </action>
        </pluginExecution>

        <pluginExecution>
            <pluginExecutionFilter>
                <groupId>org.codehaus.mojo</groupId>
                <artifactId>gwt-maven-plugin</artifactId>
                <goals>
                    <goal>compile</goal>
                </goals>
                <versionRange>[0.0,)</versionRange>
            </pluginExecutionFilter>
            <action>
                <ignore />
            </action>
        </pluginExecution>

        <pluginExecution>
            <pluginExecutionFilter>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-dependency-plugin</artifactId>
                <goals>
                    <goal>copy-dependencies</goal>
                    <goal>unpack</goal>
                </goals>
                <versionRange>[0.0,)</versionRange>
            </pluginExecutionFilter>
            <action>
                <ignore />
            </action>
        </pluginExecution>

        <pluginExecution>
            <pluginExecutionFilter>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-antrun-plugin</artifactId>
                <versionRange>[1.7,)</versionRange>
                <goals>
                    <goal>run</goal>
                </goals>
            </pluginExecutionFilter>
            <action>
                <ignore />
            </action>
        </pluginExecution>


        <pluginExecution>
            <pluginExecutionFilter>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-checkstyle-plugin</artifactId>
                <versionRange>[2.8,)</versionRange>
                <goals>
                    <goal>check</goal>
                </goals>
            </pluginExecutionFilter>
            <action>
                <ignore />
            </action>
        </pluginExecution>

    </pluginExecutions>
</lifecycleMappingMetadata>

请注意，目前Eclipse Neon发布系列中提供的M2Eclipse (m2e)版本1.7.0支持指定生命周期映射元数据的新语法。结果是这样的样板文件(这里我们告诉m2e忽略目标):

<pluginManagement>
  <plugins>
    <!--This plugin's configuration is used to store Eclipse m2e settings only. It has no influence on the Maven build itself.-->
    <plugin>
      <groupId>org.eclipse.m2e</groupId>
      <artifactId>lifecycle-mapping</artifactId>
      <version>1.0.0</version>
      <configuration>
        <lifecycleMappingMetadata>
          <pluginExecutions>
            <pluginExecution>
              <pluginExecutionFilter>
                <groupId>org.codehaus.mojo</groupId>
                <artifactId>exec-maven-plugin</artifactId>
                <versionRange>[1.5.0,)</versionRange>
                <goals>
                  <goal>exec</goal>
                </goals>
              </pluginExecutionFilter>
              <action>
                <ignore></ignore>
              </action>
            </pluginExecution>
          </pluginExecutions>
        </lifecycleMappingMetadata>
      </configuration>
    </plugin>
  </plugins>
</pluginManagement>

可以在插件的执行节点中替换为一行:

<?m2e ignore?>

有关详细信息，请参阅发行说明。

见https://www.eclipse.org/m2e/documentation/m2e-execution-not-covered.html。

To solve some long-standing issues, m2e 1.0 requires explicit instructions what to do with all Maven plugins bound to "interesting" phases of project build lifecycle. We call these instructions "project build lifecycle mapping" or simply "lifecycle mapping" because they define how m2e maps information from project pom.xml file to Eclipse workspace project configuration and behaviour during Eclipse workspace build. Project build lifecycle mapping configuration can be specified in project pom.xml, contributed by Eclipse plugins and there is also default configuration for some commonly used Maven plugins shipped with m2e. We call these "lifecycle mapping metadata sources". m2e will create error marker like below for all plugin executions that do not have lifecycle mapping in any of the mapping metadata sources. Plugin execution not covered by lifecycle configuration: org.apache.maven.plugins:maven-antrun-plugin:1.3:run (execution: generate-sources-input, phase: generate-sources) m2e matches plugin executions to actions using combination of plugin groupId, artifactId, version range and goal. There are three basic actions that m2e can be instructed to do with a plugin execution -- ignore, execute and delegate to a project configurator.