Obwohl das hierarchische Dependency Injection System sehr einfach zu definieren und zu verwenden ist, ist es dennoch sehr mächtig.

Sie können Abhängigkeiten definieren, die selbst wiederum Abhängigkeiten definieren können.

                    && a.getArtifactId().equals("tools")) {
                // The system scoped dependencies will be present in the classloader for the plugin
                return;
            }
        }

        fail("Can't find the system scoped dependency in the plugin artifacts.");
    }

          if (response.request().header("Authorization") != null) {
            return null; // Give up, we've already attempted to authenticate.
          }

          System.out.println("Authenticating for response: " + response);
          System.out.println("Challenges: " + response.challenges());
          String credential = Credentials.basic("jesse", "password1");
          return response.request().newBuilder()

    @Nonnull
    Map<String, String> getUserProperties();

    /**
     * Returns immutable system properties to use for interpolation. The system properties are collected from the
     * runtime environment such as {@link System#getProperties()} and environment variables
     * (prefixed with {@code env.}).
     *
     * @return the system properties, never {@code null}
     */
    @Nonnull
    Map<String, String> getSystemProperties();

// TODO(b/65488446): Make this a public API.
/** Utility method to parse the system class path. */
@NullUnmarked
final class ClassPathUtil {
  private ClassPathUtil() {}

  /**
   * Returns the URLs in the class path specified by the {@code java.class.path} {@linkplain
   * System#getProperty system property}.
   */
  // TODO(b/65488446): Make this a public API.
  static URL[] parseJavaClassPath() {

      private var nextId = 1

      override fun newThread(runnable: Runnable): Thread = Thread(runnable, "$name-${nextId++}")
    }
}

fun getEnv(name: String) = System.getenv(name)

val SYSTEM_FILE_SYSTEM = FileSystem.SYSTEM

        Activation defaultActivation = new Activation();

        defaultActivation.setActiveByDefault(true);

        defaultActivated.setActivation(defaultActivation);

        Properties props = System.getProperties();

        ProfileManager profileManager = new DefaultProfileManager(getContainer(), props);

        profileManager.addProfile(notActivated);
        profileManager.addProfile(defaultActivated);

* A particular program while it is **running** on the operating system.
    * This doesn't refer to the file, nor to the code, it refers **specifically** to the thing that is being **executed** and managed by the operating system.
* Any program, any code, **can only do things** when it is being **executed**. So, when there's a **process running**.

import org.conscrypt.OpenSSLProvider

private fun runBatch(
  dnsProviders: List<DnsOverHttps>,
  names: List<String>,
) {
  var time = System.currentTimeMillis()
  for (dns in dnsProviders) {
    println("Testing ${dns.url}")
    for (host in names) {
      print("$host: ")
      System.out.flush()
      try {
        val results = dns.lookup(host)
        println(results)
      } catch (uhe: UnknownHostException) {

   * A ticker that reads the current time using {@link System#nanoTime}.
   *
   * @since 10.0
   */
  public static Ticker systemTicker() {
    return SYSTEM_TICKER;
  }

  private static final Ticker SYSTEM_TICKER =
      new Ticker() {
        @Override
        @SuppressWarnings("GoodTime") // reading system time without TimeSource
        public long read() {
          return System.nanoTime();
        }
      };