# Middleware { #middleware }

You can add middleware to **FastAPI** applications.

A "middleware" is a function that works with every **request** before it is processed by any specific *path operation*. And also with every **response** before returning it.

* It takes each **request** that comes to your application.
* It can then do something to that **request** or run any needed code.

    /** String object indicating that {@link #line} is empty */
    protected static final String EMPTY = new String();

    /** {@link BufferedReader} */
    protected final BufferedReader reader;

    /** The line that has been read */
    protected String line = EMPTY;

    /**
     * Returns an {@link Iterable} that wraps a {@link LineIterator} for use in enhanced for-loops.
     *

 * <ul>
 * <li>{@link Experimental}: Indicates that this interface or its implementation
 * may still be evolving and could change in future versions.</li>
 * <li>{@link FunctionalInterface}: Denotes that this is a functional interface,
 * allowing implementations as lambda expressions or method references.</li>
 * <li>{@link Consumer}: Signifies that this type is intended to be implemented

        String actualUserName = ntlmRequest.getRemoteUser();

        // Assert: Verify that the returned user name is the expected one
        assertEquals(expectedUserName, actualUserName, "getRemoteUser should return the principal's name.");
    }

    /**
     * Test method for {@link NtlmHttpServletRequest#getUserPrincipal()}.
     * Verifies that the method returns the correct principal object.
     */
    @Test

// license that can be found in the LICENSE file.

package tar

import (
	"errors"
	"fmt"
	"io"
	"io/fs"
	"maps"
	"path"
	"slices"
	"strings"
	"time"
)

// Writer provides sequential writing of a tar archive.
// [Writer.WriteHeader] begins a new file with the provided [Header],
// and then Writer can be treated as an io.Writer to supply that file's data.
type Writer struct {

## Wildcards { #wildcards }

It's also possible to declare the list as `"*"` (a "wildcard") to say that all are allowed.

But that will only allow certain types of communication, excluding everything that involves credentials: Cookies, Authorization headers like those used with Bearer Tokens, etc.

     * Test case for the encode method.
     * Verifies that the encode method of a concrete implementation is called
     * and interacts with the NdrBuffer as expected.
     * @throws NdrException if encoding fails.
     */
    @Test
    void testEncode() throws NdrException {
        // When
        ndrObject.encode(mockBuffer);

        // Then
        // Verify that our mock buffer had the expected method called.

import java.lang.reflect.Method;
import java.util.Locale;
import junit.framework.TestCase;

/**
 * Since annotations have some reusability issues that force copy and paste all over the place, it's
 * worth having a test to ensure that all our Feature enums have their annotations correctly set up.
 *
 * @author George van den Driessche
 */
public class FeatureEnumTest extends TestCase {

    /** Array of fields that can be highlighted in search results */
    protected String[] highlightedFields;

    /** Array of fields that can be searched against */
    protected String[] searchFields;

    /** Set of fields that can be searched against for O(1) lookup */
    protected Set<String> searchFieldSet;

    /** Array of fields that can be used for faceted search */

		// so we leave it out. It should be covered via
		// the ReadSlice test since ReadLine simply calls
		// ReadSlice, and it's that function that handles
		// the last byte.
	}

	// Try all readers with UnreadByte.
	for rno, read := range readers {
		// Some input data that is longer than the minimum reader buffer size.
		const n = 10
		var buf bytes.Buffer
		for i := 0; i < n; i++ {