How to embed H2 database into jar file delivered to the client?

Question

I use H2 database for a desktop application in embedded mode. When I compress the application into jar file the database file is omitted. So, when I run MyApplication.jar nothing works. What is the correct way to embed/include/connect h2.jar file with MyApplication.jar? Or maybe there is another way to deliver database and application in the bundle?

Answer 1

One common scheme is to put h2.jar in a lib directory relative to your application and include a Class-Path entry in your JAR's manifest with an entry for it:

Class-Path: lib/h2.jar lib/…

Addendum: This small project includes a link to the JAR specification and a handy utility for examining the manifest in situ.

Answer 2

If you are using Maven to build your project, just use maven-shade-plugin... great results and control, I've been using it a lot.

For embedding all your dependencies you would write something like:

  <plugin>
    <groupId>org.apache.maven.plugins</groupId>
    <artifactId>maven-shade-plugin</artifactId>
    <version>1.4</version>
    <executions>
      <execution>
        <phase>package</phase>
        <goals>
          <goal>shade</goal>
        </goals>
      </execution>
    </executions>
  </plugin>

Then with just a normal "mvn package" you'll have all your dependencies' jars included in your application jar.

With further configuration you can control what gets included and what not.

Answer 3

If you want to put the database itself in your jar file, then this explanation might help: http://www.h2database.com/html/features.html#database_in_zip

This is also discussed in this thread in the H2 forum.

Answer 4

If you're using maven to build you project take a look maven-assembly-plugin (jar-with-dependencies). This would produce single jar with all dependencies packed into it.