BundleFindingUtils.java

package org.springframework.roo.support.osgi;

import java.net.URL;

import org.apache.commons.lang3.Validate;
import org.osgi.framework.Bundle;
import org.osgi.framework.BundleContext;

/**
 * Helper to locate bundle symbolic names used by Spring Roo.
 * 
 * @author Ben Alex
 * @since 1.1.1
 */
public abstract class BundleFindingUtils {

  /**
   * Locates the first bundle that contains the presented type name and return
   * its bundle symbolic name.
   * 
   * @param context that can be used to obtain bundles to search (required)
   * @param typeNameInExternalForm a type name (eg com.foo.Bar)
   * @return the bundle symbolic name, if found (or null if not found)
   */
  public static String findFirstBundleForTypeName(final BundleContext context,
      final String typeNameInExternalForm) {
    Validate.notNull(context, "Bundle context required to perform the search");
    Validate.notBlank(typeNameInExternalForm, "Resource name to locate is required");
    final String resourceName = "/" + typeNameInExternalForm.replace('.', '/') + ".class";

    final Bundle[] bundles = context.getBundles();
    if (bundles == null) {
      return null;
    }

    for (final Bundle bundle : bundles) {
      try {
        final URL url = bundle.getEntry(resourceName);
        if (url != null) {
          return bundle.getSymbolicName();
        }
      } catch (final RuntimeException e) {
        return null;
      }
    }

    return null;
  }

  /**
   * Locates the first bundle that contains the presented type name and return
   * that class.
   * 
   * @param context that can be used to obtain bundles to search (required)
   * @param typeNameInExternalForm a type name (eg com.foo.Bar)
   * @return the class, if found (or null if not found)
   */
  public static Class<?> findFirstBundleWithType(final BundleContext context,
      final String typeNameInExternalForm) {
    Validate.notNull(context, "Bundle context required to perform the search");
    Validate.notBlank(typeNameInExternalForm, "Resource name to locate is required");
    final String resourceName = "/" + typeNameInExternalForm.replace('.', '/') + ".class";

    final Bundle[] bundles = context.getBundles();
    if (bundles == null) {
      return null;
    }

    for (final Bundle bundle : bundles) {
      try {
        final URL url = bundle.getEntry(resourceName);
        if (url != null) {
          return bundle.loadClass(typeNameInExternalForm);
        }
      } catch (final Throwable e) {
        return null;
      }
    }

    return null;
  }
}