val body = body("")
    assertThat(exhaust(body.charStream())).isEqualTo("")
  }

  @Test
  fun readerLooksLikeBomButTooShort() {
    val body = body("000048")
    assertThat(exhaust(body.charStream())).isEqualTo("\u0000\u0000H")
  }

  @Test
  fun readerDefaultsToUtf8() {
    val body = body("68656c6c6f")
    assertThat(exhaust(body.charStream())).isEqualTo("hello")
  }

  @Test

 * re-read the bytes of the response. Use this one shot to read the entire response into memory with
 * [bytes] or [string]. Or stream the response with either [source], [byteStream], or [charStream].
 */
abstract class ResponseBody : Closeable {
  /** Multiple calls to [charStream] must return the same instance. */
  private var reader: Reader? = null

  abstract fun contentType(): MediaType?

  /**

        override fun close() = TODO()
      }
    val byteStream = responseBody.byteStream()
    val source = responseBody.source()
    val bytes = responseBody.bytes()
    val charStream = responseBody.charStream()
    val string = responseBody.string()
    responseBody.close()
    responseBody = "".toResponseBody("".toMediaType())
    responseBody = "".toResponseBody(null)

[Moshi](https://github.com/square/moshi) is a handy API for converting between JSON and Java objects. Here we're using it to decode a JSON response from a GitHub API.

Note that `ResponseBody.charStream()` uses the `Content-Type` response header to select which charset to use when decoding the response body. It defaults to `UTF-8` if no charset is specified.

=== ":material-language-kotlin: Kotlin"
    ```kotlin

	public fun <init> ()V
	public final fun byteStream ()Ljava/io/InputStream;
	public final fun byteString ()Lokio/ByteString;
	public final fun bytes ()[B
	public final fun charStream ()Ljava/io/Reader;
	public fun close ()V
	public abstract fun contentLength ()J
	public abstract fun contentType ()Lokhttp3/MediaType;

	public fun <init> ()V
	public final fun byteStream ()Ljava/io/InputStream;
	public final fun byteString ()Lokio/ByteString;
	public final fun bytes ()[B
	public final fun charStream ()Ljava/io/Reader;
	public fun close ()V
	public abstract fun contentLength ()J
	public abstract fun contentType ()Lokhttp3/MediaType;

 * @since 1.0
 */
@J2ktIncompatible
@GwtIncompatible
public final class CharStreams {

  // 2K chars (4K bytes)
  private static final int DEFAULT_BUF_SIZE = 0x800;

  /** Creates a new {@code CharBuffer} for buffering reads or writes. */
  static CharBuffer createBuffer() {
    return CharBuffer.allocate(DEFAULT_BUF_SIZE);
  }

  private CharStreams() {}

  /**

    Reader empty = new StringReader("");
    assertEquals(0, CharStreams.exhaust(empty));
    assertEquals(-1, empty.read());
  }

  public void testExhaust_readable() throws IOException {
    CharBuffer buf = CharBuffer.wrap(ASCII);
    assertEquals(ASCII.length(), CharStreams.exhaust(buf));
    assertEquals(0, buf.remaining());
    assertEquals(0, CharStreams.exhaust(buf));

    Reader empty = new StringReader("");
    assertEquals(0, CharStreams.exhaust(empty));
    assertEquals(-1, empty.read());
  }

  public void testExhaust_readable() throws IOException {
    CharBuffer buf = CharBuffer.wrap(ASCII);
    assertEquals(ASCII.length(), CharStreams.exhaust(buf));
    assertEquals(0, buf.remaining());
    assertEquals(0, CharStreams.exhaust(buf));

import java.io.StringWriter;
import java.nio.Buffer;
import java.nio.CharBuffer;
import java.util.Random;
import org.jspecify.annotations.NullUnmarked;

/**
 * Benchmarks for {@link CharStreams#copy}.
 *
 * <p>{@link CharStreams#copy} has type specific optimizations for various common Appendable and
 * Reader implementations, this compares the performance of the different options.
 */