命令执行区别
mvn clean package命令：先清除工程(即清除工程target目录下的内容)，然后编译工程，运行单测，将编译后的代码打包，如打成jar包。
mvn clean install命令：先清除工程(即清除工程target目录下的内容)，然后编译工程，运行单测，将编译后的代码打包，将包安装到本地仓库。
通过对比可以看出：mvn clean package与mvn clean install命令都会先清除工程，然后编译，再打包，而mvn clean install命令多了一步将打好的包安装到本地仓库。
差异的本质
要了解mvn clean package与mvn clean install命令在执行上的差异，就要了解Maven的构建流程。
Maven三个内置构建生命周期
Maven有3个内置的构建生命周期，即default，clean，site
default：处理项目工程(project)部署clean：处理项目工程清理site：处理项目工程网站的创建
Maven的生命周期由多个阶段(phase) 组成，以内置的default生命周期为例，由以下几个阶段组成：
validate：验证工程project是正确的，且所有必要信息都是可用的。compile：编译工程源码。test：使用合适的单元测试框架测试编译后的源代码，这些测试不应该要求打包或部署代码。package：将编译后的代码打包成可发布的格式，如jar。verify：检查验证集成测试的结果。install：将包安装到本地仓库。deploy：将包推到远程仓库。
Maven命令的执行，对应的生命周期以及各阶段(phase)的执行是怎样的？
根据具体命令，可分为指定单个生命周期的命令 和 指定多个生命周期的命令，如下：
1）指定单个生命周期的phase执行
当运行mvn compile命令时，Maven会执行default生命周期，从开始阶段一直运行到compile阶段为止，即依次执行的阶段为：validate --> compile
当运行mvn package命令时，Maven会执行default生命周期，从开始阶段一直运行到package阶段为止，即依次执行的阶段为：validate --> compile --> test --> package
2）指定多个生命周期的phase执行
当运行mvn clean package命令时，Maven会先执行clean生命周期，然后再执行default生命周期，从开始阶段一直运行到package阶段为止，即依次执行的阶段为：pre-clean --> clean --> validate --> compile --> test --> package
当运行mvn clean install命令时，Maven会先执行clean生命周期，然后再执行default生命周期，从开始阶段一直运行到install阶段为止，即依次执行的阶段为：pre-clean --> clean --> validate --> compile --> test --> package --> verify --> install
官网上Maven三个内置构建生命周期所有构建阶段
官网地址：maven.apache.org/guides/intr…
1）default生命周期的所有构建阶段：
| Phase | Description |
|---|---|
| validate | validate the project is correct and all necessary information is available. |
| initialize | initialize build state, e.g. set properties or create directories. |
| generate-sources | generate any source code for inclusion in compilation. |
| process-sources | process the source code, for example to filter any values. |
| generate-resources | generate resources for inclusion in the package. |
| process-resources | copy and process the resources into the destination directory, ready for packaging. |
| compile | compile the source code of the project. |
| process-classes | post-process the generated files from compilation, for example to do bytecode enhancement on Java classes. |
| generate-test-sources | generate any test source code for inclusion in compilation. |
| process-test-sources | process the test source code, for example to filter any values. |
| generate-test-resources | create resources for testing. |
| process-test-resources | copy and process the resources into the test destination directory. |
| test-compile | compile the test source code into the test destination directory |
| process-test-classes | post-process the generated files from test compilation, for example to do bytecode enhancement on Java classes. |
| test | run tests using a suitable unit testing framework. These tests should not require the code be packaged or deployed. |
| prepare-package | perform any operations necessary to prepare a package before the actual packaging. This often results in an unpacked, processed version of the package. |
| package | take the compiled code and package it in its distributable format, such as a JAR. |
| pre-integration-test | perform actions required before integration tests are executed. This may involve things such as setting up the required environment. |
| integration-test | process and deploy the package if necessary into an environment where integration tests can be run. |
| post-integration-test | perform actions required after integration tests have been executed. This may including cleaning up the environment. |
| verify | run any checks to verify the package is valid and meets quality criteria. |
| install | install the package into the local repository, for use as a dependency in other projects locally. |
| deploy | done in an integration or release environment, copies the final package to the remote repository for sharing with other developers and projects. |
2）clean生命周期的所有构建阶段：
| Phase | Description |
|---|---|
| pre-clean | execute processes needed prior to the actual project cleaning |
| clean | remove all files generated by the previous build |
| post-clean | execute processes needed to finalize the project cleaning |
3）site生命周期的所有构建阶段：
| Phase | Description |
|---|---|
| pre-site | execute processes needed prior to the actual project site generation |
| site | generate the project's site documentation |
| post-site | execute processes needed to finalize the site generation, and to prepare for site deployment |
| site-deploy | deploy the generated site documentation to the specified web server |
