maven打包知识_不加repackage会默认打成jar包吗

如果在项目的pom.xml文件中没有指明打包类型，则默认打成jar包。使用maven命令  mvn clean package进行项目的打包，可看到如下输出结果：

[INFO] Results:
[INFO]
[INFO] Tests run: 1, Failures: 0, Errors: 0, Skipped: 0
[INFO]
[INFO]
[INFO] --- maven-jar-plugin:3.1.2:jar (default-jar) @ springboot ---
[INFO] Building jar: D:\Spring\springboot\target\springboot-0.0.1-SNAPSHOT.jar
[INFO]
[INFO] --- spring-boot-maven-plugin:2.1.6.RELEASE:repackage (repackage) @ springboot ---
[INFO] Replacing main artifact with repackaged archive
[INFO] ------------------------------------------------------------------------
[INFO] BUILD SUCCESS
[INFO] ------------------------------------------------------------------------
[INFO] Total time: 16.318 s
[INFO] Finished at: 2019-07-25T22:42:05+08:00
[INFO] Final Memory: 35M/252M
[INFO] ------------------------------------------------------------------------

可以看到   maven-jar-plugin:3.1.2:jar (default-jar) @ springboot  其实就是利用jar插件将项目打成了springboot-0.0.1-SNAPSHOT.jar，该文件会存放在target目录下。

如果要让其他的maven项目直接引用这个jar包，还要执行mvn clean install命令，输出结果为：

[INFO] Tests run: 1, Failures: 0, Errors: 0, Skipped: 0
[INFO]
[INFO]
[INFO] --- maven-jar-plugin:3.1.2:jar (default-jar) @ springboot ---
[INFO] Building jar: D:\Spring\springboot\target\springboot-0.0.1-SNAPSHOT.jar
[INFO]
[INFO] --- spring-boot-maven-plugin:2.1.6.RELEASE:repackage (repackage) @ springboot ---
[INFO] Replacing main artifact with repackaged archive
[INFO]
[INFO] --- maven-install-plugin:2.5.2:install (default-install) @ springboot ---
[INFO] Installing D:\Spring\springboot\target\springboot-0.0.1-SNAPSHOT.jar to D:\Spring\maven-space
\repository\com\example\springboot\0.0.1-SNAPSHOT\springboot-0.0.1-SNAPSHOT.jar
[INFO] Installing D:\Spring\springboot\pom.xml to D:\Spring\maven-space\repository\com\example\sprin
gboot\0.0.1-SNAPSHOT\springboot-0.0.1-SNAPSHOT.pom
[INFO] ------------------------------------------------------------------------
[INFO] BUILD SUCCESS
[INFO] ------------------------------------------------------------------------
[INFO] Total time: 18.514 s
[INFO] Finished at: 2019-07-25T22:53:22+08:00
[INFO] Final Memory: 35M/261M
[INFO] ------------------------------------------------------------------------

在打包之后，我们又执行了安装任务install:install，从输出我们看到该任务将项目输出的jar安装到了Maven本地仓库中，我们可以打开相应的文件夹看到项目的pom和jar。只有将项目的构件安装到本地仓库之后，其他Maven项目才能使用它。