able to discuss the full details of what you're working on.


        But Guava aims to provide features that are useful across boundaries of projects, companies,
        or even industries — utilities useful for a sizable proportion of all Java programmers
        everywhere. If you can give enough detail such that any of us can imagine coming across

Now let's build from the previous chapter and add the missing parts to have a complete security flow.

## Get the `username` and `password` { #get-the-username-and-password }

We are going to use **FastAPI** security utilities to get the `username` and `password`.

OAuth2 specifies that when using the "password flow" (that we are using) the client/user must send a `username` and `password` fields as form data.

import java.util.function.BinaryOperator;
import java.util.function.Function;
import java.util.function.Supplier;
import java.util.stream.Collector;
import org.jspecify.annotations.Nullable;

/** Collectors utilities for {@code common.collect.Table} internals. */
@GwtCompatible
final class TableCollectors {

  static <T extends @Nullable Object, R, C, V>
      Collector<T, ?, ImmutableTable<R, C, V>> toImmutableTable(

 * limitations under the License.
 */

package com.google.common.math;

import java.math.BigInteger;
import java.util.Random;
import org.jspecify.annotations.NullUnmarked;

/**
 * Utilities for benchmarks.
 *
 * <p>In many cases, we wish to vary the order of magnitude of the input as much as we want to vary
 * the input itself, so most methods which generate values use an exponential distribution varying

	<groupId>org.codelibs</groupId>
	<artifactId>corelib</artifactId>
	<packaging>jar</packaging>
	<name>CodeLibs Core Library</name>
	<version>0.7.2-SNAPSHOT</version>
	<description>Core library providing essential utilities and functionalities.</description>
	<url>https://github.com/codelibs/corelib</url>
	<inceptionYear>2012</inceptionYear>
	<licenses>
		<license>
			<name>The Apache Software License, Version 2.0</name>

	// Most notably, it cannot support sparse files, files larger than 8GiB,
	// filenames larger than 256 characters, and non-ASCII filenames.
	//
	// Reference:
	//	http://pubs.opengroup.org/onlinepubs/9699919799/utilities/pax.html#tag_20_92_13_06
	FormatUSTAR

	// FormatPAX represents the PAX header format defined in POSIX.1-2001.
	//
	// PAX extends USTAR by writing a special file with Typeflag TypeXHeader

import com.google.caliper.BeforeExperiment;
import com.google.caliper.Benchmark;
import com.google.caliper.Param;
import org.jspecify.annotations.NullUnmarked;

/**
 * Benchmarks against the Apache Commons Math utilities.
 *
 * <p>Note: the Apache benchmarks are not open sourced to avoid the extra dependency.
 *
 * @author Louis Wasserman
 */
@NullUnmarked
public class ApacheBenchmark {
  private enum Impl {
    GUAVA {

import com.google.caliper.BeforeExperiment;
import com.google.caliper.Benchmark;
import com.google.caliper.Param;
import org.jspecify.annotations.NullUnmarked;

/**
 * Benchmarks against the Apache Commons Math utilities.
 *
 * <p>Note: the Apache benchmarks are not open sourced to avoid the extra dependency.
 *
 * @author Louis Wasserman
 */
@NullUnmarked
public class ApacheBenchmark {
  private enum Impl {
    GUAVA {

 *       add overloads that accept start and end indexes.
 *   <li>Can be streamed without "breaking the chain": {@code foo.getBarLongs().stream()...}.
 *   <li>Access to all collection-based utilities via {@link #asList} (though at the cost of
 *       allocating garbage).
 * </ul>
 *
 * <p>Disadvantages compared to {@code long[]}:
 *
 * <ul>

/// tip | 提示
整合像 Google、Facebook、X（Twitter）、GitHub 等其他身分驗證/授權提供者也是可行而且相對容易。

最複雜的部分其實是打造一個類似那樣的身分驗證/授權提供者，但 **FastAPI** 提供了工具，能替你處理繁重工作，讓你更輕鬆完成。
///

## **FastAPI** 工具 { #fastapi-utilities }

FastAPI 在 `fastapi.security` 模組中為上述各種安全性方案提供了多種工具，讓這些機制更容易使用。

接下來的章節會示範如何使用這些 **FastAPI** 提供的工具，為你的 API 加入安全性。