maven-dependency-plugin (goals "copy-dependencies","unpack") is not supported by m2e

 解决办法：在plugins之前添加如下pluginManagement，二者前后顺序如下：
   <build>  
            <pluginManagement>  
                <plugins>  
                    <plugin>  
                        <groupId>org.eclipse.m2e</groupId>  
                        <artifactId>lifecycle-mapping</artifactId>  
                        <version>1.0.0</version>  
                        <configuration>  
                            <lifecycleMappingMetadata>  
                                <pluginExecutions>  
                                    <pluginExecution>  
                                        <pluginExecutionFilter>  
                                            <groupId>org.apache.maven.plugins</groupId>  
                                            <artifactId>maven-dependency-plugin</artifactId>  
                                            <versionRange>[2.0,)</versionRange>  
                                            <goals>  
                                                <goal>copy-dependencies</goal>  
                                            </goals>  
                                        </pluginExecutionFilter>  
                                        <action>  
                                            <ignore />  
                                        </action>  
                                    </pluginExecution>  
                                </pluginExecutions>  
                            </lifecycleMappingMetadata>  
                        </configuration>  
                    </plugin>  
                </plugins>  
            </pluginManagement>  
            <plugins>  
                <plugin>  
                    <groupId>org.apache.maven.plugins</groupId>  
                    <artifactId>maven-dependency-plugin</artifactId>  
                    <executions>  
                        <execution>  
                            <id>copy-dependencies</id>  
                            <phase>package</phase>  
                            <goals>  
                                <goal>copy-dependencies</goal>  
                            </goals>  
                            <configuration>  
                                <outputDirectory>${project.build.directory}/lib</outputDirectory>  
                                <excludeTransitive>false</excludeTransitive>  
                                <stripVersion>true</stripVersion>  
                            </configuration>  
                        </execution>  
                    </executions>  
                </plugin>  
            </plugins>  
        </build>