Springboot源码分析之项目结构

摘要:

• 无论是从IDEA还是其他的SDS开发工具亦或是https://start.spring.io/ 进行解压,我们都会得到同样的一个pom.xml文件

      <?xml version="1.0" encoding="UTF-8"?>      <project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"               xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">          <modelVersion>4.0.0</modelVersion>          <parent>              <groupId>org.springframework.boot</groupId>              <artifactId>spring-boot-starter-parent</artifactId>              <version>2.1.6.RELEASE</version>              <relativePath/> <!-- lookup parent from repository -->          </parent>          <groupId>com.github.dqqzj</groupId>          <artifactId>springboot</artifactId>          <version>0.0.1-SNAPSHOT</version>          <name>springboot</name>          <packaging>jar</packaging>          <description>Demo project for Spring Boot</description>          <properties>              <java.version>1.8</java.version>          </properties>          <dependencies>              <dependency>                  <groupId>org.springframework.boot</groupId>                  <artifactId>spring-boot-starter</artifactId>              </dependency>              <dependency>                  <groupId>org.springframework.boot</groupId>                  <artifactId>spring-boot-starter-test</artifactId>                  <scope>test</scope>              </dependency>          </dependencies>          <build>              <plugins>                  <plugin>                      <groupId>org.springframework.boot</groupId>                      <artifactId>spring-boot-maven-plugin</artifactId>                  </plugin>              </plugins>          </build>      </project>

parent标签的含义

• 找到本地仓库的spring-boot-starter-parent 坐标

    <?xml version="1.0" encoding="utf-8"?><project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">      <modelVersion>4.0.0</modelVersion>      <parent>        <groupId>org.springframework.boot</groupId>        <artifactId>spring-boot-dependencies</artifactId>        <version>2.1.6.RELEASE</version>        <relativePath>../../spring-boot-dependencies</relativePath>      </parent>     <!-- 省略无关代码...... -->      <build>      <!-- 省略无关代码...... -->        <pluginManagement>          <plugins>           <!-- 省略无关代码...... -->            <plugin>              <groupId>org.springframework.boot</groupId>              <artifactId>spring-boot-maven-plugin</artifactId>              <executions>                <execution>                  <id>repackage</id>                  <goals>                    <goal>repackage</goal>                  </goals>                </execution>              </executions>              <configuration>                <mainClass>${start-class}</mainClass>              </configuration>            </plugin>            <!-- 省略无关代码...... -->          </plugins>        </pluginManagement>      </build>    </project>

关注点

    <parent>        <groupId>org.springframework.boot</groupId>        <artifactId>spring-boot-dependencies</artifactId>        <version>2.1.6.RELEASE</version>        <relativePath>../../spring-boot-dependencies</relativePath>      </parent>

说明我们的工程可以进行改造进行替换掉原来工程的parent标签.

    <plugin>                <groupId>org.springframework.boot</groupId>                <artifactId>spring-boot-maven-plugin</artifactId>                <executions>                  <execution>                    <id>repackage</id>                    <goals>                      <goal>repackage</goal>                    </goals>                  </execution>                </executions>                <configuration>                  <mainClass>${start-class}</mainClass>                </configuration>              </plugin>

repackage必须要有否则打jar包时候无法正常启动.

在配置文件加上repackage即可

    <build>            <plugins>                <plugin>                    <groupId>org.springframework.boot</groupId>                    <artifactId>spring-boot-maven-plugin</artifactId>                    <executions>                        <execution>                            <goals>                                <goal>repackage</goal>                            </goals>                        </execution>                    </executions>                </plugin>            </plugins>        </build>

IDEA自带maven工具

mvnw是基于linux的shell脚本命令

mvnw.cmd是基于windows的脚本命令

.mvn包含了 maven下载路径以及版本等信息

也就是说我们完全不用自己下载maven而是可以直接使用IDEA给我们提供的工具即可，只不过通常不会这么做。

repackage的作用

• 官方文档

正常情况下打包会生成springboot-0.0.1-SNAPSHOT.jar.original,springboot-0.0.1-SNAPSHOT.jar这样的2个文件，而repackage的作用就是将springboot-0.0.1-SNAPSHOT.jar.original重新打包为我们可以执行的springboot-0.0.1-SNAPSHOT.jar