Resolving imports for java.nio.ByteBuffer, java.util.Formatter


#1

I am having some trouble importing some of the libraries.

For example, I can see in the MicroEJ documentation, that java.util.Formatter should be supported: https://developer.microej.com/javadoc/microej_4.1/addons/java/util/Formatter.html

But when I try to import java.util.Formatter in my project, I get an error saying that the import cannot be resolved. I am guessing this is maybe a configuration issue with my project?

I see a similar issue when I try to import java.nio.ByteBuffer. I can see it documented here:
https://developer.microej.com/javadoc/microej_4.1/addons/java/nio/ByteBuffer.html#ByteBuffer--

But I get an error “The import java.nio cannot be resolved” when I try to import it. Do you have any ideas how I can resolve? Thanks!


#2

Hi David,

The MicroEJ Java libraries are split in two types (see http://developer.microej.com/#APIs):

  • Foundation Libraries: implementation is specific to the platform ; depends on C ; built-in in the MicroEJ Architectures
  • Add-on Libraries: full java implementation ; available on the MicroEJ Central Repository (ivy repository)

The ByteBuffer and Formatter classes are both available in add-on libraries. You can use it either by adding manually the Jars in your project classpath configuration or using Ivy dependency manager.
Ivy manages automatically the transitive dependencies of a library. You can find here a simple example that uses Ivy to retrieve logging library: https://github.com/MicroEJ/Example-Standalone-Eclasspath/tree/master/com.microej.examples.eclasspath.logging . The dependencies are declared in the module.ivy file.

The Formatter library that includes the Formatter class is available here: http://developer.microej.com/4.1/ivy/artifacts/ej/library/eclasspath/formatter/2.0.0/
The ByteBuffer library that includes the ByteBuffer class is available here: http://developer.microej.com/4.1/ivy/artifacts/ej/library/eclasspath/bytebuffer/1.0.1/

Most of the typical J2SE classes are available in these libraries: http://developer.microej.com/4.1/ivy/artifacts/ej/library/eclasspath/

You can find here a list of all the add-on libraries classes: http://developer.microej.com/javadoc/microej_4.1/addons/index.html
And here a list of all the foundation libraries classes: http://developer.microej.com/javadoc/microej_4.1/foundation/index.html

More information here:

Jerome