maven?springboot如何將jar包打包到指定目錄

更新時間：2021年12月18日 15:33:06 作者：烤鴨的世界我們不懂

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如何將jar包打包到指定目錄

今天分享一下springboot將jar包打包到指定目錄下。

由于之前上線都是一個打包到一個jar，由于服務多了，1個包100多M，哪怕是小版本上線都需要重新上傳jar包。

1.目的

將不常用的比如spring,druid等不常用打包到lib目錄，這樣每次上線不需要上傳這些。第三方或者常改動的還打包到本身的jar包內，每次上線都會新打包。

這樣原來的100多M的jar包，可以變成2、3M。

如圖所示：

原來的打包方式

改后的方式：

2.修改pom

簡單解釋一下，includes標簽內就是打入jar包第三方jar。將上面的2M的包解壓縮后，就是includes的包。

如圖所示。

excludeGroupIds和excludeArtifactIds 是配置不在lib目錄里的包，由于java啟動加載的機制是優(yōu)先加載jar包，再加載外部目錄，如果jar包都存在兩個地方，這樣配置就沒有意義了，每次還是得重新發(fā)布lib目錄，所以將includes中的包，再在excludeGroupIds 和 excludeArtifactIds 配置上。

<build>
    <plugins>
        <plugin>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-maven-plugin</artifactId>
            <version>2.0.5.RELEASE</version>
            <executions>
                <execution>
                    <goals>
                        <goal>repackage</goal>
                        <goal>build-info</goal>
                    </goals>
                </execution>
            </executions>
            <configuration>
                <layout>ZIP</layout>
                <includes>
                    <include>
                        <groupId>nothing</groupId>
                        <artifactId>nothing</artifactId>
                    </include>
                    <include>
                        <groupId>com.etc</groupId>
                        <artifactId>etc-manage-api</artifactId>
                    </include>
                    <include>
                        <groupId>com.etc</groupId>
                        <artifactId>etc-manage-core</artifactId>
                    </include>
                    <include>
                        <groupId>com.etc</groupId>
                        <artifactId>etc-manage-rpc-api</artifactId>
                    </include>
                    <include>
                        <groupId>com.sinoiov.etc.apollo</groupId>
                        <artifactId>apollo-spring-boot-starter</artifactId>
                    </include>
                </includes>
            </configuration>
        </plugin>
        <plugin>
            <groupId>org.apache.maven.plugins</groupId>
            <artifactId>maven-dependency-plugin</artifactId>
            <executions>
                <execution>
                    <id>copy</id>
                    <phase>package</phase>
                    <goals>
                        <goal>copy-dependencies</goal>
                    </goals>
                    <configuration>
                        <excludeGroupIds>
                            com.sinoiov.etc.apollo
                        </excludeGroupIds>
                        <excludeArtifactIds>
                            etc-manage-api,etc-manage-core,etc-manage-rpc-api
                        </excludeArtifactIds>
                        <outputDirectory>${project.build.directory}/lib</outputDirectory>
                    </configuration>
                </execution>
            </executions>
        </plugin>
    </plugins>
</build>

3.修改啟動腳本

原腳本

java -jar etc-manage-service-basic-2.2.0.jar

現腳本 (如果相對目錄不好用，就用絕對目錄試試)

java Dloader.path=../lib  -jar etc-manage-service-basic-2.2.0.jar

jar包外指定配置文件及原理

解決方案

修改maven的pom.xml文件

不拷貝資源文件

<resources>
    <resource>
        <directory>src/main/resources</directory>
        <excludes>
            <exclude>*</exclude>
        </excludes>
        <filtering>true</filtering>
    </resource>
</resources>

修改打包方式

<plugin>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-maven-plugin</artifactId>
    <configuration>
        <layout>ZIP</layout>
    </configuration>
</plugin>

運行

假設application.properties和application-{profile}.properties都在/tmp/temp/config，jar文件在/tmp/temp

java -Dloader.path=file:///tmp/temp/config,demo-1.0.jar -jar demo-1.0.jar

原理

對比jar包中MANIFEST.MF文件在`ZIP配置前后的區(qū)別

配置前：

Main-Class: org.springframework.boot.loader.JarLauncher
Start-Class: com.chinaunicom.gateway.GatewayApplication

配置后：

Main-Class: org.springframework.boot.loader.PropertiesLauncher
Start-Class: com.chinaunicom.gateway.GatewayApplication

發(fā)現是類加載器變了，查看org.springframework.boot.loader包下所有加載器實現：

這里寫圖片描述

查看五個類描述：官方文檔

JarLauncher

Launcher for JAR based archives. This launcher assumes that dependency jars are included inside a /BOOT-INF/lib directory and that application classes are included inside a /BOOT-INF/classes directory.

WarLauncher

Launcher for WAR based archives. This launcher for standard WAR archives. Supports dependencies in WEB-INF/lib as well as WEB-INF/lib-provided, classes are loaded from WEB-INF/classes.

PropertiesLauncher

Launcher for archives with user-configured classpath and main class via a properties file. This model is often more flexible and more amenable to creating well-behaved OS-level services than a model based on executable jars.
Looks in various places for a properties file to extract loader settings, defaulting to application.properties either on the current classpath or in the current working directory. The name of the properties file can be changed by setting a System property loader.config.name (e.g. -Dloader.config.name=foo will look for foo.properties. If that file doesn't exist then tries loader.config.location (with allowed prefixes classpath: and file: or any valid URL). Once that file is located turns it into Properties and extracts optional values (which can also be provided overridden as System properties in case the file doesn't exist):
loader.path: a comma-separated list of directories (containing file resources and/or nested archives in .jar or .zip or archives) or archives to append to the classpath. BOOT-INF/classes,BOOT-INF/lib in the application archive are always used
loader.main: the main method to delegate execution to once the class loader is set up. No default, but will fall back to looking for a Start-Class in a MANIFEST.MF, if there is one in ${loader.home}/META-INF.

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