1.找到eclipse目录：
查看目录下是否有lifecycle-mapping-metadata.xml文件，若没有新建，内容如下：
<?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>
</pluginExecutions>
</lifecycleMappingMetadata>2.再次打开window>Preferences>maven> Lifecycle Mappings
点击Reload 红框中按钮，再点击apply即可
