CODEWITHSUNDEEP
javamaven
SantiM
SantiM

Reputation: 312

How to execute an already compiled jar while building my project in Maven

I am developing a library and I need to automatically generate a .java file before compiling. I found out a the maven-exec-plugin and I configured it in this way

<plugin>
  <groupId>org.codehaus.mojo</groupId>
  <artifactId>exec-maven-plugin</artifactId>
  <version>1.2.1</version>
  <executions>
    <execution>
      <id>generate-city-enum</id>
      <phase>generate-sources</phase>
      <goals>
        <goal>java</goal>
      </goals>
      <configuration>
        <executable>java</executable>
        <mainClass>org.codeforamerica.open311.city_enum_builder.EnumBuilder</mainClass>
        <arguments>
          <argument>-jar</argument>
          <argument>city_enum_builder.jar</argument>
          <argument>cities.json</argument>
          <arguments>output.java</arguments>
        </arguments>
      </configuration>
    </execution>
 </executions>
</plugin>

The problem is that running mvn -e compile I get the following error:

java.lang.ClassNotFoundException: org.codeforamerica.open311.city_enum_builder.EnumBuilder

However, this is the main class, and, indeed, if I execute java -cp .:city_enum_builder.jar org.codeforamerica.open311.city_enum_builder.EnumBuilder cities.json output.java it works.

In addition, this .jar doesn't need to specify a class in order to get executed (java -jar city_enum_builder.jar cities.json output.java works as well).

Thank you.

Upvotes: 0

Views: 176

Answers (1)

Gyro Gearless
Gyro Gearless

Reputation: 5279

I suppose you confuse the parameters for the exec:exec goal (which spawns an external process) with exec:java (which just executes some Java class in Mavens VM).

(So for your example, <executable>java</executable> will be ignored (so no java.exe called) and obviously your class itself doesnt know how to resolve classpaths.

So add the project providing your city_enum_builder.jar as dependency to your exec-maven-plugin and it should work.

And dont forget to check http://mojo.codehaus.org/exec-maven-plugin/java-mojo.html for more details.

Upvotes: 1

Related Questions