[ERROR] No goals have been specified for this build. You must specify a valid lifecycle phase or a goal in the format <plugin-prefix>:<goal> or <plugin-group-id>:<plugin-artifact-id>[:<plugin-version>]:<goal>. Available lifecycle phases are: validate, initialize, generate-sources, process-sources, generate-resources, process-resources, compile, process-classes, generate-test-sources, process-test-sources, generate-test-resources, process-test-resources, test-compile, process-test-classes, test, prepare-package, package, pre-integration-test, integration-test, post-integration-test, verify, install, deploy, pre-clean, clean, post-clean, pre-site, site, post-site, site-deploy. -> [Help 1]
[ERROR]
[ERROR] To see the full stack trace of the errors, re-run Maven with the -e switch.
[ERROR] Re-run Maven using the -X switch to enable full debug logging.
[ERROR]
[ERROR] For more information about the errors and possible solutions, please read the following articles:
[ERROR] [Help 1] http://cwiki.apache.org/confluence/display/MAVEN/NoGoalSpecifiedException
Build step 'Invoke top-level Maven targets' marked build as failure
Finished: FAILURE
1.只要在pom文件中增加一行<defaultGoal>compile</defaultGoal>就行啦！
2.项目pom文件要放在jenkins的workspace下
3.pom文件中的标签scope，scope为依赖范围，若依赖范围为test，则某个jar包只对测试有效。换句话说，测试代码中import JUnit是有效的，但是在主代码中import JUnit是无法通过编译的；如果不声明范围的话，就是默认compile；
4.在maven执行测试之前，maven会自动执行项目主资源处理、主代码编译、测试资源处理、测试代码编译；