import org.codelibs.fess.crawler.exception.ExtractException;
import org.codelibs.fess.crawler.exception.MaxLengthExceededException;
import org.codelibs.fess.crawler.extractor.Extractor;
import org.codelibs.fess.crawler.extractor.ExtractorFactory;
import org.codelibs.fess.crawler.helper.MimeTypeHelper;
import org.codelibs.fess.crawler.util.IgnoreCloseInputStream;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

	if metadata {
		checkObjMeta = func(name string, action policy.Action) (s3Err APIErrorCode) {
			return checkRequestAuthType(ctx, r, action, bucket, name)
		}
	}
	urlValues := r.Form

	// Extract all the listBucketVersions query params to their native values.
	prefix, marker, delimiter, maxkeys, encodingType, versionIDMarker, errCode := getListBucketObjectVersionsArgs(urlValues)
	if errCode != ErrNone {

	if err != ErrNone {
		return err
	}

	// Extract all the signed headers along with its values.
	extractedSignedHeaders, errCode := extractSignedHeaders(signV4Values.SignedHeaders, r)
	if errCode != ErrNone {
		return errCode
	}

	cred, _, s3Err := checkKeyValid(r, signV4Values.Credential.accessKey)
	if s3Err != ErrNone {
		return s3Err
	}

	// Extract date, if not present throw error.
	var date string

```

////

**FastAPI** will **extract** the data for **each field** from the **query parameters** in the request and give you the Pydantic model you defined.

## Check the Docs

You can see the query parameters in the docs UI at `/docs`:

<div class="screenshot">
<img src="/img/tutorial/query-param-models/image01.png">
</div>

## Forbid Extra Query Parameters

import org.codelibs.fess.crawler.exception.ExtractException;
import org.codelibs.fess.crawler.exception.MaxLengthExceededException;
import org.codelibs.fess.crawler.extractor.Extractor;
import org.codelibs.fess.crawler.extractor.ExtractorFactory;
import org.codelibs.fess.crawler.helper.MimeTypeHelper;
import org.codelibs.fess.crawler.util.IgnoreCloseInputStream;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

        this(time, properties != null ? properties.get(BUILD_TIMESTAMP_FORMAT_PROPERTY) : null);
    }

    /**
     *
     * @deprecated Use {@link #MavenBuildTimestamp(Date, Map)} or extract the format and pass it
     *             to {@link #MavenBuildTimestamp(Date, String)} instead.
     */
    @Deprecated
    public MavenBuildTimestamp(Date time, Properties properties) {

// All values stored with a key starting with one of the following prefixes
// must be extracted from the header.
var userMetadataKeyPrefixes = []string{
	"x-amz-meta-",
	"x-minio-meta-",
}

// extractMetadataFromReq extracts metadata from HTTP header and HTTP queryString.
func extractMetadataFromReq(ctx context.Context, r *http.Request) (metadata map[string]string, err error) {

   * typically useful for {@code return} statements. That leaves the code with two options: Either
   * add the suppression to the whole method (which turns off checking for a large section of code),
   * or extract a variable, and put the suppression on that. However, a local variable typically
   * doesn't work: Because nullness analyses typically infer the nullness of local variables,

   * typically useful for {@code return} statements. That leaves the code with two options: Either
   * add the suppression to the whole method (which turns off checking for a large section of code),
   * or extract a variable, and put the suppression on that. However, a local variable typically
   * doesn't work: Because nullness analyses typically infer the nullness of local variables,

// KMS data key. Otherwise, it returns an error.
func (sses3) ParseMetadata(metadata map[string]string) (keyID string, kmsKey []byte, sealedKey SealedKey, err error) {
	// Extract all required values from object metadata
	b64IV, ok := metadata[MetaIV]
	if !ok {
		return keyID, kmsKey, sealedKey, errMissingInternalIV
	}
	algorithm, ok := metadata[MetaAlgorithm]
	if !ok {