コード例 #1
0
/**
 * The repository maintains informations about class interdependencies, e.g., whether a class is a
 * sub-class of another. Delegates actual class loading to SyntheticRepository with current class
 * path by default.
 *
 * @see com.sun.org.apache.bcel.internal.util.Repository
 * @see com.sun.org.apache.bcel.internal.util.SyntheticRepository
 * @author <A HREF="mailto:[email protected]">M. Dahm</A>
 */
public abstract class Repository {
  private static com.sun.org.apache.bcel.internal.util.Repository _repository =
      SyntheticRepository.getInstance();

  /** @return currently used repository instance */
  public static com.sun.org.apache.bcel.internal.util.Repository getRepository() {
    return _repository;
  }

  /** Set repository instance to be used for class loading */
  public static void setRepository(com.sun.org.apache.bcel.internal.util.Repository rep) {
    _repository = rep;
  }

  /**
   * Lookup class somewhere found on your CLASSPATH, or whereever the repository instance looks for
   * it.
   *
   * @return class object for given fully qualified class name, or null if the class could not be
   *     found or parsed correctly
   */
  public static JavaClass lookupClass(String class_name) {
    try {
      JavaClass clazz = _repository.findClass(class_name);

      if (clazz == null) {
        return _repository.loadClass(class_name);
      } else {
        return clazz;
      }
    } catch (ClassNotFoundException ex) {
      return null;
    }
  }

  /**
   * Try to find class source via getResourceAsStream().
   *
   * @see Class
   * @return JavaClass object for given runtime class
   */
  public static JavaClass lookupClass(Class clazz) {
    try {
      return _repository.loadClass(clazz);
    } catch (ClassNotFoundException ex) {
      return null;
    }
  }

  /** @return class file object for given Java class. */
  public static ClassPath.ClassFile lookupClassFile(String class_name) {
    try {
      return ClassPath.SYSTEM_CLASS_PATH.getClassFile(class_name);
    } catch (IOException e) {
      return null;
    }
  }

  /** Clear the repository. */
  public static void clearCache() {
    _repository.clear();
  }

  /**
   * Add clazz to repository if there isn't an equally named class already in there.
   *
   * @return old entry in repository
   */
  public static JavaClass addClass(JavaClass clazz) {
    JavaClass old = _repository.findClass(clazz.getClassName());
    _repository.storeClass(clazz);
    return old;
  }

  /** Remove class with given (fully qualified) name from repository. */
  public static void removeClass(String clazz) {
    _repository.removeClass(_repository.findClass(clazz));
  }

  /** Remove given class from repository. */
  public static void removeClass(JavaClass clazz) {
    _repository.removeClass(clazz);
  }

  /**
   * @return list of super classes of clazz in ascending order, i.e., Object is always the last
   *     element
   */
  public static JavaClass[] getSuperClasses(JavaClass clazz) {
    return clazz.getSuperClasses();
  }

  /**
   * @return list of super classes of clazz in ascending order, i.e., Object is always the last
   *     element. return "null", if class cannot be found.
   */
  public static JavaClass[] getSuperClasses(String class_name) {
    JavaClass jc = lookupClass(class_name);
    return (jc == null ? null : getSuperClasses(jc));
  }

  /**
   * @return all interfaces implemented by class and its super classes and the interfaces that those
   *     interfaces extend, and so on. (Some people call this a transitive hull).
   */
  public static JavaClass[] getInterfaces(JavaClass clazz) {
    return clazz.getAllInterfaces();
  }

  /**
   * @return all interfaces implemented by class and its super classes and the interfaces that
   *     extend those interfaces, and so on
   */
  public static JavaClass[] getInterfaces(String class_name) {
    return getInterfaces(lookupClass(class_name));
  }

  /**
   * Equivalent to runtime "instanceof" operator.
   *
   * @return true, if clazz is an instance of super_class
   */
  public static boolean instanceOf(JavaClass clazz, JavaClass super_class) {
    return clazz.instanceOf(super_class);
  }

  /** @return true, if clazz is an instance of super_class */
  public static boolean instanceOf(String clazz, String super_class) {
    return instanceOf(lookupClass(clazz), lookupClass(super_class));
  }

  /** @return true, if clazz is an instance of super_class */
  public static boolean instanceOf(JavaClass clazz, String super_class) {
    return instanceOf(clazz, lookupClass(super_class));
  }

  /** @return true, if clazz is an instance of super_class */
  public static boolean instanceOf(String clazz, JavaClass super_class) {
    return instanceOf(lookupClass(clazz), super_class);
  }

  /** @return true, if clazz is an implementation of interface inter */
  public static boolean implementationOf(JavaClass clazz, JavaClass inter) {
    return clazz.implementationOf(inter);
  }

  /** @return true, if clazz is an implementation of interface inter */
  public static boolean implementationOf(String clazz, String inter) {
    return implementationOf(lookupClass(clazz), lookupClass(inter));
  }

  /** @return true, if clazz is an implementation of interface inter */
  public static boolean implementationOf(JavaClass clazz, String inter) {
    return implementationOf(clazz, lookupClass(inter));
  }

  /** @return true, if clazz is an implementation of interface inter */
  public static boolean implementationOf(String clazz, JavaClass inter) {
    return implementationOf(lookupClass(clazz), inter);
  }
}