如何用Maven解压依赖Jar并将类文件打包至War指定目录

Got it, let's solve this problem step by step. Assuming you're using Maven (the most common build tool for Java JAR/WAR projects), here are the exact configurations you need to modify in module-B's pom.xml to extract module-A's classes directly into your WAR file's target directory, instead of bundling the module-A JAR itself.

Step 1: Unpack module-A's JAR into module-B's compile output #

Use the Maven Dependency Plugin to unpack module-A's class files into target/classes (the directory that gets packaged into WEB-INF/classes in the WAR). Add this to the <build><plugins> section of module-B's pom.xml:

<plugin>
    <groupId>org.apache.maven.plugins</groupId>
    <artifactId>maven-dependency-plugin</artifactId>
    <executions>
        <execution>
            <id>unpack-module-a-classes</id>
            <phase>prepare-package</phase> <!-- Run right before packaging -->
            <goals>
                <goal>unpack</goal>
            </goals>
            <configuration>
                <artifactItems>
                    <artifactItem>
                        <!-- Replace with your actual module-A coordinates -->
                        <groupId>com.yourorg</groupId>
                        <artifactId>module-A</artifactId>
                        <version>1.0.0</version>
                        <outputDirectory>${project.build.directory}/classes</outputDirectory>
                        <includes>**/*.class</includes> <!-- Only extract class files -->
                        <!-- Add <includes>**/*.properties</includes> if you need resource files too -->
                    </artifactItem>
                </artifactItems>
            </configuration>
        </execution>
    </executions>
</plugin>

Step 2: Exclude module-A's JAR from the WAR #

To avoid having both the extracted classes and the original JAR in your WAR, configure the Maven War Plugin to exclude module-A's JAR from the WEB-INF/lib folder:

<plugin>
    <groupId>org.apache.maven.plugins</groupId>
    <artifactId>maven-war-plugin</artifactId>
    <configuration>
        <packagingExcludes>WEB-INF/lib/module-A-*.jar</packagingExcludes>
    </configuration>
</plugin>

For Gradle Users #

If you're using Gradle instead, add this to module-B's build.gradle file:

war {
    // Extract module-A's classes into WEB-INF/classes
    from zipTree(configurations.runtimeClasspath.find { it.name.startsWith('module-A') }) {
        include '**/*.class'
        into 'WEB-INF/classes'
    }
    // Exclude the original module-A JAR from the WAR
    exclude 'WEB-INF/lib/module-A-*.jar'
}

Key Notes #

• Replace the placeholder coordinates (groupId, artifactId, version) with your actual module-A details.
• If you need to extract non-class resources (like .properties or .xml files), adjust the <includes> (Maven) or include (Gradle) patterns to include those file types.
• Run mvn clean package (Maven) or ./gradlew clean war (Gradle) to build the modified WAR—you'll now see module-A's classes directly under WEB-INF/classes in the WAR, with no module-A JAR in WEB-INF/lib.

内容的提问来源于stack exchange，提问作者Subhashc