在Maven項目中,一般是jar文件的依賴,但是也要考慮一種情況,那就是war項目的依賴。
比如說base war項目包含基本的網頁,但是需要爲另外有一個定製的war項目有幾個頁面是需要特別定製的。
直接拷貝base war所有的頁面到新的定製的war項目,會帶來很大的冗餘,並且以後公共的部分有問題的話,需要兩處一起修改,這不是個好的解決辦法。
Maven 的war plugin 的overlay可以解決這個問題
1) 完成後的文件列表:
a)注意其中的黃色部分在兩個項目中都有,否則會導致第二個Springboot application 無法啓動
b) 在爲WX項目打包的時候,紅色的index.html會被藍色的index.html覆蓋
2) 父項目的pom文件, 注意項目packaging 爲pom, 而不是Jar或者war
並且列出了下屬的子maven module
<?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>2.1.1.RELEASE</version>
<relativePath/>
</parent>
<groupId>com.sz</groupId>
<artifactId>EstateManagementProject</artifactId>
<version>0.0.1-SNAPSHOT</version>
<packaging>pom</packaging>
<name>Parent</name>
<description>父項目</description>
<modules>
<module>EstateManagement-Base</module>
<module>EstateManagement-WX</module>
</modules>
</project>
3) base 子項目的pom文件, 普通的一個SpringBoot 項目
<?xml version="1.0"?>
<project
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd"
xmlns="http://maven.apache.org/POM/4.0.0"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
<modelVersion>4.0.0</modelVersion>
<parent>
<groupId>com.sz</groupId>
<artifactId>EstateManagementProject</artifactId>
<version>0.0.1-SNAPSHOT</version>
</parent>
<groupId>com.sz</groupId>
<artifactId>EstateManagement-Base</artifactId>
<packaging>war</packaging>
<name>EstateManagement-Base Maven Webapp</name>
<url>http://maven.apache.org</url>
<properties>
<java.version>1.8</java.version>
</properties>
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-tomcat</artifactId>
<scope>provided</scope>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<scope>test</scope>
</dependency>
</dependencies>
<build>
<finalName>base</finalName>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
</plugin>
</plugins>
</build>
</project>
4) WX子項目的pom文件:
a)依賴於base項目
b)SpringBoot打包的時候排除base項目,否則會把base以war的形式放在lib-provided,浪費空間
c) overlay部分指定依賴base項目
d) 可以排除某些文件
<?xml version="1.0"?>
<project
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd"
xmlns="http://maven.apache.org/POM/4.0.0"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
<modelVersion>4.0.0</modelVersion>
<parent>
<groupId>com.sz</groupId>
<artifactId>EstateManagementProject</artifactId>
<version>0.0.1-SNAPSHOT</version>
</parent>
<groupId>zhishusz2</groupId>
<artifactId>EstateManagement-WX</artifactId>
<packaging>war</packaging>
<name>EstateManagement-WX</name>
<url>http://maven.apache.org</url>
<properties>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
</properties>
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-tomcat</artifactId>
<scope>provided</scope>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<scope>test</scope>
</dependency>
<dependency>
<groupId>com.sz</groupId>
<artifactId>EstateManagement-Base</artifactId>
<version>0.0.1-SNAPSHOT</version>
<type>war</type>
<scope>provided</scope>
</dependency>
</dependencies>
<build>
<finalName>wx</finalName>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
<configuration>
<excludes>
<exclude>
<!-- 不要把依賴的war包含到本地lib-provided目錄 -->
<groupId>com.sz</groupId>
<artifactId>EstateManagement-Base</artifactId>
</exclude>
</excludes>
</configuration>
</plugin>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-war-plugin</artifactId>
<configuration>
<overlays>
<overlay>
<groupId>com.sz</groupId>
<artifactId>EstateManagement-Base</artifactId>
<!-- 排除指定的文件 -->
<excludes>
<exclude>WEB-INF/classes/com/bank2/exclude/**</exclude>
</excludes>
</overlay>
</overlays>
<failOnMissingWebXml>false</failOnMissingWebXml>
<!-- class文件會自動打JAR包 -->
<archiveClasses>false</archiveClasses>
</configuration>
</plugin>
</plugins>
</build>
</project>
5) 以SpringBoot啓動wx項目後,無法訪問base項目的 base/index.html文件,但是以普通tomcat的war項目啓動,則沒有這個限制。
6)附加,BASE項目可以用把class文件單獨打包併發布到Maven repository
<plugin>
<artifactId>maven-war-plugin</artifactId>
<configuration>
<!-- 把class打包jar作爲附件 -->
<attachClasses>true</attachClasses>
</configuration>
</plugin>
然後WX項目可以用以下依賴
<dependency>
<groupId>com.sz</groupId>
<artifactId>EstateManagement-Base</artifactId>
<version>0.0.1-SNAPSHOT</version>
<type>jar</type>
<classifier>classes</classifier>
<scope>provided</scope>
</dependency>