* [X-Forwarded-Host](https://developer.mozilla.org/en-US/docs/Web/HTTP/Reference/Headers/X-Forwarded-Host)

///

然而，因為**應用伺服器**並不知道自己在受信任的**代理**之後，預設情況下它不會信任這些標頭。

但你可以設定**應用伺服器**去信任由**代理**送來的「轉發」標頭。若你使用 FastAPI CLI，可以用 *CLI 參數* `--forwarded-allow-ips` 指定應信任哪些 IP 來的「轉發」標頭。

例如，如果**應用伺服器**只會接收來自受信任**代理**的連線，你可以設定 `--forwarded-allow-ips="*"`，也就是信任所有來源 IP，因為實際上它只會收到**代理**那個 IP 送來的請求。

				Host: "127.0.0.1:9000",
				Header: map[string][]string{
					"X-Forwarded-Scheme": {httpScheme},
				},
			},
			bucket:           "testbucket1",
			object:           "test/1.txt",
			expectedLocation: "http://127.0.0.1:9000/testbucket1/test/1.txt",
		},
		{
			request: &http.Request{
				Host: "127.0.0.1:9000",
				Header: map[string][]string{
					"X-Forwarded-Scheme": {httpsScheme},
				},
			},

 * @since 16.0
 */
@Beta
public final class HashingOutputStream extends FilterOutputStream {
  private final Hasher hasher;

  /**
   * Creates an output stream that hashes using the given {@link HashFunction}, and forwards all
   * data written to it to the underlying {@link OutputStream}.
   *
   * <p>The {@link OutputStream} should not be written to before or after the hand-off.
   */

import com.google.common.base.Preconditions;
import com.google.common.collect.ImmutableMap;
import com.google.errorprone.annotations.CanIgnoreReturnValue;
import java.util.concurrent.ExecutionException;

/**
 * A cache which forwards all its method calls to another cache. Subclasses should override one or
 * more methods to modify the behavior of the backing cache as desired per the <a
 * href="http://en.wikipedia.org/wiki/Decorator_pattern">decorator pattern</a>.

import com.google.errorprone.annotations.CanIgnoreReturnValue;
import java.util.Collection;
import java.util.Map;
import java.util.Set;
import org.jspecify.annotations.Nullable;

/**
 * A table which forwards all its method calls to another table. Subclasses should override one or
 * more methods to modify the behavior of the backing map as desired per the <a
 * href="http://en.wikipedia.org/wiki/Decorator_pattern">decorator pattern</a>.

* [X-Forwarded-Host](https://developer.mozilla.org/en-US/docs/Web/HTTP/Reference/Headers/X-Forwarded-Host)

///

不过，由于**应用服务器**并不知道自己位于受信任的**代理**之后，默认情况下，它不会信任这些请求头。

但你可以配置**应用服务器**去信任由**代理**发送的这些“转发”请求头。如果你在使用 FastAPI CLI，可以使用命令行选项 `--forwarded-allow-ips` 指定它应该信任哪些 IP 发来的这些“转发”请求头。

例如，如果**应用服务器**只接收来自受信任**代理**的通信，你可以设置 `--forwarded-allow-ips="*"`，让它信任所有传入的 IP，因为它只会接收来自**代理**所使用 IP 的请求。

        NdrHyper hyper = new NdrHyper(0L);
        assertThrows(NullPointerException.class, () -> hyper.decode(null));
    }

    /**
     * Verify that the encode method forwards the value to NdrBuffer.
     */
    @Test
    @DisplayName("Encode should call NdrBuffer.enc_ndr_hyper with correct value")
    public void testEncodeInteraction() throws NdrException {

        if (isTrustedProxy(remoteAddr)) {
            final String xForwardedFor = request.getHeader("X-Forwarded-For");
            if (StringUtil.isNotBlank(xForwardedFor)) {
                final String clientIp = xForwardedFor.split(",")[0].trim();
                if (logger.isDebugEnabled()) {
                    logger.debug("Client IP from X-Forwarded-For: clientIp={}, remoteAddr={}", clientIp, remoteAddr);
                }

  // BND is incompatible with Kotlin/Multiplatform because it assumes the JVM source set's
  // name is
  // 'main'. Work around this by creating a 'main' source set that forwards to 'jvmMain'.
  //
  // The forwarding SourceSet also needs to fake out some task names to prevent them from
  // being
  // registered twice.
  //
  // https://github.com/bndtools/bnd/issues/6590

import com.google.common.base.Preconditions;
import com.google.common.collect.ImmutableMap;
import com.google.errorprone.annotations.CanIgnoreReturnValue;
import java.util.concurrent.ExecutionException;

/**
 * A cache which forwards all its method calls to another cache. Subclasses should override one or
 * more methods to modify the behavior of the backing cache as desired per the <a
 * href="http://en.wikipedia.org/wiki/Decorator_pattern">decorator pattern</a>.