手动编译Android Studio项目时，如何用通配符打包仅含.class的.jar？

Hey there, I’ve run into this exact issue before when manually packaging Java projects—let’s get you sorted out! The problem with using *.class directly often boils down to how your shell handles wildcards or missing recursive support for subdirectories. Here are a few reliable solutions:

Solution 1: Target .class Files in the Current Directory (If They’re All There) #

If all your compiled .class files are in your current working directory, run this command:

jar -cf Package.jar *.class

Note: If you get an error here, it’s likely because there are no .class files in your current directory—double-check you’re in the right folder (usually something like build/classes/java/main for Android Studio projects). If your shell can’t expand *.class, it’ll pass the literal string to jar, which will throw an error because no file named *.class exists.

Solution 2: Recursively Package All .class Files (Including Subdirectories) #

Android Studio projects often have .class files organized in subdirectories matching your package structure. Use find to locate all .class files and pass them to jar:

find . -name "*.class" -exec jar -cf Package.jar {} +

This command will:

• Search recursively from your current directory (.)
• Find every file ending with .class
• Pass all those files to jar to package into Package.jar

Solution 3: Switch to the Compiled Classes Directory First #

Navigate to the root folder where all your .class files are stored (skip the source folders with .java files entirely). For most Android Studio projects, this is typically:

cd app/build/intermediates/javac/debug/classes

Then package everything in this directory (which should only be .class files and package subdirectories):

jar -cf ../../../../../Package.jar *

The ../../../../../ part just navigates back up to your project root to place the jar file there—adjust the number of ../ based on your directory structure.

Bonus: Use Maven/Gradle (Since You Know It’s More Convenient) #

Since you mentioned Maven is easier, for completeness, here’s a quick tip: configure the Maven Jar Plugin in your pom.xml to automatically package only compiled classes, no source files:

<build>
  <plugins>
    <plugin>
      <groupId>org.apache.maven.plugins</groupId>
      <artifactId>maven-jar-plugin</artifactId>
      <version>3.3.0</version>
      <configuration>
        <includes>
          <include>**/*.class</include>
        </includes>
      </configuration>
    </plugin>
  </plugins>
</build>

Run mvn package and it’ll handle the rest without manual commands!

内容的提问来源于stack exchange，提问作者Jared Nielsen