* </p>
 * <pre>
 * Map&lt;K, V&gt; syncMap = Collections.synchronizedMap(new LruHashMap&lt;&gt;(100));
 * </pre>
 * <p>
 * Alternatively, for high-concurrency scenarios, consider implementing a custom
 * LRU cache using {@link java.util.concurrent.ConcurrentHashMap} with an eviction strategy.
 * </p>
 *
 * @author koichik
 * @param <K> the key type
 * @param <V> the value type
 */

# JSON with Bytes as Base64 { #json-with-bytes-as-base64 }

If your app needs to receive and send JSON data, but you need to include binary data in it, you can encode it as base64.

## Base64 vs Files { #base64-vs-files }

Consider first if you can use [Request Files](../tutorial/request-files.md) for uploading binary data and [Custom Response - FileResponse](./custom-response.md#fileresponse--fileresponse-) for sending binary data, instead of encoding it in JSON.

      fail("index " + i + ", expected is exhausted, actual <" + actualIterator.next() + ">");
    }
  }

  /**
   * Verifies that a collection is immutable.
   *
   * <p>A collection is considered immutable if:
   *
   * <ol>
   *   <li>All its mutation methods result in UnsupportedOperationException, and do not change the
   *       underlying contents.

import org.apache.maven.api.annotations.Nonnull;

/**
 * Represents a repository backed by an IDE workspace, the output of a build session,
 * or similar ad-hoc collections of artifacts. This repository is considered read-only
 * within the context of a session, meaning it can only be used for artifact resolution,
 * not for installation or deployment. This interface does not provide direct access

      <plugin>
        <groupId>org.codehaus.mojo</groupId>
        <artifactId>animal-sniffer-maven-plugin</artifactId>
        <configuration>
          <checkTestClasses>false</checkTestClasses> <!-- TODO(cpovirk): Consider checking them. -->
        </configuration>
      </plugin>
      <plugin>
        <groupId>org.codehaus.mojo</groupId>
        <artifactId>build-helper-maven-plugin</artifactId>

    }

    @Override
    public Object getKey() {
        return "artifact " + artifact.getGroupId() + ":" + artifact.getArtifactId();
    }

    @Override
    public boolean isSnapshot() {
        // Don't consider the artifact's version in here, as this is stored in the directory above that
        return false;
    }

    @Override
    public int getNature() {
        if (artifact.getVersion() != null) {

    // user-specified -XX:+DisableExplicitGC.
    //
    // TODO(user): Consider using
    // java/lang/management/OperatingSystemMXBean.html#getSystemLoadAverage()
    //
    // TODO(user): Consider scaling by number of mutator threads,
    // e.g. using Thread#activeCount()
    return max(10L, Runtime.getRuntime().totalMemory() / (32L * 1024L * 1024L));
  }

        Iterator<? extends Entry<? extends E>> iterator1 = multiset1.entrySet().iterator();
        Iterator<? extends Entry<? extends E>> iterator2 = multiset2.entrySet().iterator();
        // TODO(lowasser): consider making the entries live views
        return new AbstractIterator<Entry<E>>() {
          @Override
          protected @Nullable Entry<E> computeNext() {
            if (iterator1.hasNext()) {

        Iterator<? extends Entry<? extends E>> iterator1 = multiset1.entrySet().iterator();
        Iterator<? extends Entry<? extends E>> iterator2 = multiset2.entrySet().iterator();
        // TODO(lowasser): consider making the entries live views
        return new AbstractIterator<Entry<E>>() {
          @Override
          protected @Nullable Entry<E> computeNext() {
            if (iterator1.hasNext()) {

import junit.framework.Test;

/**
 * Tests the {@link Map} implementations of {@link java.util}, suppressing tests that trip known
 * bugs in OpenJDK 6 or higher.
 *
 * @author Kevin Bourrillion
 */
// TODO(cpovirk): consider renaming this class in light of our now running it under newer JDKs.
@AndroidIncompatible // test-suite builders
public class OpenJdk6MapTests extends TestsForMapsInJavaUtil {
  public static Test suite() {