demo/plugins/org.argeo.demo.i18n/src/main/java/org/argeo/demo/i18n/ImplementationLoader.java

   1 package org.argeo.demo.i18n;
   2
   3 import java.text.MessageFormat;
   4
   5 import org.apache.commons.logging.Log;
   6 import org.apache.commons.logging.LogFactory;
   7
   8 /**
   9  * This class enable single sourcing between RAP and RCP. For this to run
  10  * correctly, following conventions must be respected:
  11  * <ul>
  12  * <li>Given the fact that a common interface named Xxx is defined in package
  13  * aa.bb.cc, corresponding implementation named XxxImpl must be found in package
  14  * aa.bb.cc.specific of both RAP and RCP UI bundles.
  15  *
  16  * thanks to {@link http
  17  * ://eclipsesource.com/en/info/rcp-rap-single-sourcing-guideline/}, chapter 7
  18  */
  19
  20 public class ImplementationLoader {
  21         private final static Log log = LogFactory
  22                         .getLog(ImplementationLoader.class);
  23
  24         public static Object newInstance(
  25                         @SuppressWarnings("rawtypes") final Class type) {
  26                 String name = type.getName();
  27                 // manually construct the implementation name for the given interface,
  28                 // assuming that convention have been respected.
  29                 String cName = type.getCanonicalName();
  30                 String pName = cName.substring(0, cName.lastIndexOf('.') + 1);
  31                 String sName = cName.substring(cName.lastIndexOf('.') + 1);
  32                 String implName = pName + "specific." + sName + "Impl";
  33                 // String implName = cName + "Impl";
  34                 Object result = null;
  35                 try {
  36                         result = type.getClassLoader().loadClass(implName).newInstance();
  37                 } catch (Throwable throwable) {
  38                         String txt = "Could not load implementation for {0}";
  39                         String msg = MessageFormat.format(txt, new Object[] { name });
  40                         throw new RuntimeException(msg, throwable);
  41                 }
  42                 return result;
  43         }
  44 }