"content": {"application/json": {"schema": {}}},
                        },
                        "422": {
                            "description": "Validation Error",
                            "content": {
                                "application/json": {
                                    "schema": {

                                    }
                                }
                            },
                        },
                        "422": {
                            "description": "Validation Error",
                            "content": {
                                "application/json": {
                                    "schema": {

 * governing permissions and limitations under the License.
 */
package org.codelibs.fess.app.web.admin.crawlinginfo;

import org.lastaflute.web.validation.Required;
import org.lastaflute.web.validation.theme.conversion.ValidateTypeFailure;

import jakarta.validation.constraints.Size;

/**
 * Form class for editing crawling information in the admin interface.
 * This form handles the editing of crawling session data, which tracks

    /**
     * Constructs and validates a PAC from raw data using provided Kerberos keys.
     * @param data the raw PAC data bytes
     * @param keys map of Kerberos keys for signature validation
     * @throws PACDecodingException if the PAC data is malformed or signature validation fails
     */
    public Pac(byte[] data, Map<Integer, KerberosKey> keys) throws PACDecodingException {
        byte[] checksumData = data.clone();
        try {

if [ -n "${distributionSha256Sum-}" ]; then
  distributionSha256Result=false
  if [ "$MVN_CMD" = mvnd.sh ]; then
    echo "Checksum validation is not supported for maven-mvnd." >&2
    echo "Please disable validation by removing 'distributionSha256Sum' from your maven-wrapper.properties." >&2
    exit 1
  elif command -v sha256sum >/dev/null; then

 * governing permissions and limitations under the License.
 */
package org.codelibs.fess.app.web.admin.design;

import org.lastaflute.web.validation.Required;

/**
 * Form class for file access operations in the admin design interface.
 * This form handles file name validation for accessing design files.
 */
public class FileAccessForm {

    /** The name of the file to access (required) */
    @Required

So, with that type declaration, **FastAPI** gives you automatic request <abbr title="converting the string that comes from an HTTP request into Python data">"parsing"</abbr>.

///

## Data validation { #data-validation }

But if you go to the browser at <a href="http://127.0.0.1:8000/items/foo" class="external-link" target="_blank">http://127.0.0.1:8000/items/foo</a>, you will see a nice HTTP error of:

```JSON
{

    }
}
```

Again, doing just that declaration, with **FastAPI** you get:

* Editor support (completion, etc.), even for nested models
* Data conversion
* Data validation
* Automatic documentation

## Special types and validation { #special-types-and-validation }

Apart from normal singular types like `str`, `int`, `float`, etc. you can use more complex singular types that inherit from `str`.

@Named
public interface ModelTransformer extends SpiService {

    /**
     * Apply a transformation on the file model.
     *
     * This method will be called on each file model being loaded,
     * just before validation.
     *
     * @param model the input model
     * @return the transformed model, or the input model if no transformation is needed
     * @throws ModelTransformerException
     */
    @Nonnull

client = TestClient(app)


def test_get_validation_error():
    response = client.get("/items/foo")
    assert response.status_code == 400, response.text
    assert "Validation errors:" in response.text
    assert "Field: ('path', 'item_id')" in response.text


def test_get_http_error():
    response = client.get("/items/3")
    assert response.status_code == 418, response.text