---
title: Recipes
description: A collection of common/useful code examples for Kotlin and Java
---


# Recipes

We've written some recipes that demonstrate how to solve common problems with OkHttp. Read through them to learn about how everything works together. Cut-and-paste these examples freely; that's what they're for.

### Synchronous Get ([.kt][SynchronousGetKotlin], [.java][SynchronousGetJava])

 * either express or implied. See the License for the specific language
 * governing permissions and limitations under the License.
 */
package org.codelibs.core.beans.util;

import static org.codelibs.core.collection.CollectionsUtil.newLinkedHashMap;
import static org.codelibs.core.misc.AssertionUtil.assertArgumentNotNull;

import java.util.Map;
import java.util.Map.Entry;
import java.util.function.Consumer;

   *
   * <p>If the mapped keys or values contain duplicates (according to {@link
   * Object#equals(Object)}), an {@code IllegalArgumentException} is thrown when the collection
   * operation is performed. (This differs from the {@code Collector} returned by {@link
   * Collectors#toMap(Function, Function)}, which throws an {@code IllegalStateException}.)
   *
   * @since 21.0
   */

* custom resources that use unconventional pluralization now work properly with kubectl and garbage collection ([#50012](https://github.com/kubernetes/kubernetes/pull/50012), [@deads2k](https://github.com/deads2k))

a struct with a <code>_size</code> field), <code>#include
"go_asm.h"</code> will fail with a "redefinition of macro" error.
</p>

<h3 id="runtime">Runtime Coordination</h3>

<p>
For garbage collection to run correctly, the runtime must know the
location of pointers in all global data and in most stack frames.
The Go compiler emits this information when compiling Go source files,

 *
 * <p><b>Warning:</b> The comparison must be <i>consistent with equals</i> as explained by the
 * {@link Comparable} class specification. Otherwise, the resulting multiset will violate the {@link
 * java.util.Collection} contract, which is specified in terms of {@link Object#equals}.
 *
 * <p>See the Guava User Guide article on <a href=
 * "https://github.com/google/guava/wiki/NewCollectionTypesExplained#multiset">{@code Multiset}</a>.
 *

## Metrics Request Handling

Each endpoint can be queried as needed via a scrape configuration in Prometheus or a compatible metrics collection tool. You should schedule scrape operations so a prior scrape completes before the next one begins.

 *       to check these for the most central aspects of functionality.) So, most tests use the
 *       smallest sensible numbers of threads, collection sizes, etc needed to check basic
 *       conformance.
 *   <li>The test classes currently do not declare inclusion in any particular package to simplify
 *       things for people integrating them in TCK test suites.

   *
   * <p>NOTE: an IPv6 address coerced to an IPv4 address can only be used for such purposes as
   * rudimentary identification or indexing into a collection of real {@link InetAddress}es. They
   * cannot be used as real addresses for the purposes of network communication.
   *
   * @param ip {@link InetAddress} to convert

import java.lang.reflect.ParameterizedType;
import java.lang.reflect.Type;
import java.lang.reflect.TypeVariable;
import java.lang.reflect.WildcardType;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Collections;
import java.util.List;
import java.util.Map;
import junit.framework.TestCase;

/**
 * Test cases for {@link TypeToken}.
 *
 * @author Sven Mawson
 * @author Ben Yu
 */