Java Code Examples for java.util.Collections#emptyEnumeration()

Enumeration<String> entryNames(CodeSource[] cs) {
    ensureInitialization();
    if (jv != null) {
        return jv.entryNames(this, cs);
    }

    /*
     * JAR file has no signed content. Is there a non-signing
     * code source?
     */
    boolean includeUnsigned = false;
    for (CodeSource c : cs) {
        if (c.getCodeSigners() == null) {
            includeUnsigned = true;
            break;
        }
    }
    if (includeUnsigned) {
        return unsignedEntryNames();
    } else {
        return Collections.emptyEnumeration();
    }
}
 

@Override
public Enumeration<String> getAttributeNames() {
    final Map<String, Object> attributes = routingContext.data();
    if (attributes == null) {
        return Collections.emptyEnumeration();
    } else {
        Enumeration<String> en = new Enumeration<String>() {
            private Iterator<String> it = attributes.keySet().iterator();

            @Override
            public boolean hasMoreElements() {
                return it.hasNext();
            }

            @Override
            public String nextElement() {
                return it.next();
            }
        };
        return en;
    }
}
 

@Override
public Enumeration<String> attributes(String name) {
    Item item = getItem(name);
    if (item != null) {
        return item.getAttributes();
    } else {
        return Collections.emptyEnumeration();
    }
}
 

/**
 * Returns the URLs of all resources of the given name on the class path.
 */
private Enumeration<URL> findResourcesOnClassPath(String name) {
    if (hasClassPath()) {
        if (System.getSecurityManager() == null) {
            return ucp.findResources(name, false);
        } else {
            PrivilegedAction<Enumeration<URL>> pa;
            pa = () -> ucp.findResources(name, false);
            return AccessController.doPrivileged(pa);
        }
    } else {
        // no class path
        return Collections.emptyEnumeration();
    }
}
 

public static Enumeration<String> parameters() {
    final RequestAttributes attributes = RequestContextHolder.getRequestAttributes();
    if (attributes != null && attributes instanceof ServletRequestAttributes) {
        return ((ServletRequestAttributes) attributes).getRequest().getParameterNames();
    }
    return Collections.emptyEnumeration();
}
 

/**
 * Creates a new {@code PluginsClassLoader} with the specified set of files
 * providing the JAR paths.
 *
 * @param files The {@code File} objects providing the JAR paths.
 */
public PluginsClassLoader(final Set<File> files) {
  // Override parent ClassLoader methods to avoid delegation of resource
  // resolution to bootstrap class loader
  super(AssembleUtil.toURLs(files), new ClassLoader(null) {
    // Overridden to ensure resources are not discovered in bootstrap class loader
    @Override
    public Enumeration<URL> getResources(final String name) throws IOException {
      return Collections.<URL>emptyEnumeration();
    }
  });
  this.set = files;
  this.array = files.toArray(new File[files.size()]);
}
 

@Override
public Enumeration<URL> findResources(String name) throws IOException {
    Enumeration<URL> origResources = getParent().getResources(name);
    Enumeration<URL> deleResources = oldDelegate != null ? oldDelegate.findResources(name) : Collections.<URL>emptyEnumeration();
    
    return new CompoundEnumeration<URL>(new Enumeration[] {
            origResources,
            deleResources,
            super.findResources(name)
    });
}
 

@Override
public Enumeration<URL> getResources(String name) throws IOException {

    if (name.equals(EXTENSION)) {
        return Collections.emptyEnumeration();
    }

    return super.getResources(name);
}
 

public Enumeration getAttributeNames() {
    return Collections.emptyEnumeration();
}
 

@SuppressWarnings("rawtypes")
@Override
public Enumeration getAttributeNames() {
    return Collections.emptyEnumeration();
}
 

public Enumeration getAttributeNames() {
    return Collections.emptyEnumeration();
}
 

public Enumeration getAttributeNames() {
    return Collections.emptyEnumeration();
}
 

@Override
public Enumeration<String> getInitParameterNames() {
    return Collections.emptyEnumeration();
}
 

@Override
public Enumeration<URL> getResources(String name) throws IOException {
  if (debug) {
    System.err.println("getResources(" + name + ")");
  }
  Enumeration<URL> result = null;
  if (!systemPackage.isSystem(name)) {
    // Search local repositories
    if (debug) {
      System.err.println("  Searching local repositories");
    }
    result = findResources(name);
    if (result != null && result.hasMoreElements()) {
      if (debug) {
        System.err.println("  --> Returning result from local");
      }
      return result;
    }
    if (applicationPackage.isApplication(name)) {
      if (debug) {
        System.err.println("  --> application class, returning empty enumeration");
      }
      return Collections.emptyEnumeration();
    }
  }
  // Delegate to parent unconditionally
  if (debug) {
    System.err.println("  Delegating to parent classloader unconditionally " + parent);
  }
  result = parent.getResources(name);
  if (result != null && result.hasMoreElements()) {
    if (debug) {
      List<URL> resultList = Collections.list(result);
      result = Collections.enumeration(resultList);
      System.err.println("  --> Returning result from parent: " + resultList);
    }
    return result;
  }
  // (4) Resource was not found
  if (debug) {
    System.err.println("  --> Resource not found, returning empty enumeration");
  }
  return Collections.emptyEnumeration();
}
 

public Enumeration getAttributeNames() {
    return Collections.emptyEnumeration();
}
 

public Enumeration getAttributeNames() {
    return Collections.emptyEnumeration();
}
 

@Override
public Enumeration<URL> findEntries(String path, String filePattern, boolean recurse) {
    return Collections.emptyEnumeration();
}
 

@Override
public Enumeration<String> getInitParameterNames() {
    return Collections.emptyEnumeration();
}
 

public Enumeration<?> getAttributeNames() {
    return Collections.emptyEnumeration();
}
 

/**
 * Returns an enumeration of {@link java.net.URL URL} objects
 * representing all the resources with the given name. Class loader
 * implementations should override this method.
 *
 * <p> For resources in named modules then the method must implement the
 * rules for encapsulation specified in the {@code Module} {@link
 * Module#getResourceAsStream getResourceAsStream} method. Additionally,
 * it must not find non-"{@code .class}" resources in packages of named
 * modules unless the package is {@link Module#isOpen(String) opened}
 * unconditionally. </p>
 *
 * @implSpec The default implementation returns an enumeration that
 * contains no elements.
 *
 * @param  name
 *         The resource name
 *
 * @return  An enumeration of {@link java.net.URL URL} objects for
 *          the resource. If no resources could  be found, the enumeration
 *          will be empty. Resources for which a {@code URL} cannot be
 *          constructed, are in a package that is not opened unconditionally,
 *          or access to the resource is denied by the security manager,
 *          are not returned in the enumeration.
 *
 * @throws  IOException
 *          If I/O errors occur
 *
 * @since  1.2
 * @revised 9
 * @spec JPMS
 */
protected Enumeration<URL> findResources(String name) throws IOException {
    return Collections.emptyEnumeration();
}