* System#getProperty(String)}.
   *
   * <p>The value returned by this method is non-null except in rare circumstances:
   *
   * <ul>
   *   <li>{@link #JAVA_EXT_DIRS} was deprecated in Java 8 and removed in Java 9. We have not
   *       confirmed whether it is available under older versions.

# 在雲端部署 FastAPI

你幾乎可以使用**任何雲端供應商**來部署你的 FastAPI 應用程式。

在大多數情況下，主要的雲端供應商都有部署 FastAPI 的指南。

## 雲端供應商 - 贊助商

一些雲端供應商 ✨ [**贊助 FastAPI**](../help-fastapi.md#sponsor-the-author){.internal-link target=_blank} ✨，這確保了 FastAPI 及其**生態系統**持續健康地**發展**。

這也展現了他們對 FastAPI 和其**社群**（包括你）的真正承諾，他們不僅希望為你提供**優質的服務**，還希望確保你擁有一個**良好且健康的框架**：FastAPI。🙇

 * This interface extends the general {@link Options} interface, adding upgrade-specific configuration options.
 *
 * @since 4.0.0
 */
@Experimental
public interface UpgradeOptions extends Options {
    /**
     * Returns the list of upgrade goals to be executed.
     * These goals can include operations like "check", "dependencies", "plugins", etc.
     *

import org.xml.sax.InputSource;

/**
 * {@link XpathTransformer} is a class that transforms HTML content into XML format based on XPath expressions.
 * It extracts data from an HTML document by applying XPath rules defined in {@link #fieldRuleMap}.
 * The extracted data is then formatted into an XML structure and stored in the {@link ResultData}.
 * <p>
 * This class extends {@link HtmlTransformer} and overrides the {@link #storeData(ResponseData, ResultData)} method

   * ordering of all views in the returned table, with {@link #putAll} following the {@link
   * Table#cellSet()} iteration order. However, if {@link #orderRowsBy} or {@link #orderColumnsBy}
   * is called, the views are sorted by the supplied comparators.
   *
   * <p>For empty or single-cell immutable tables, {@link #of()} and {@link #of(Object, Object,
   * Object)} are even more convenient.
   *

import org.jspecify.annotations.Nullable;

/**
 * A {@link BiMap} whose contents will never change, with many other important properties detailed
 * at {@link ImmutableCollection}.
 *
 * @author Jared Levy
 * @since 2.0
 */
@GwtCompatible
public abstract class ImmutableBiMap<K, V> extends ImmutableMap<K, V> implements BiMap<K, V> {

  /**

`TestClient` 是基于 <a href="https://www.python-httpx.org" class="external-link" target="_blank">HTTPX</a> 的。幸运的是，我们可以直接使用它来测试API。

## 示例

举个简单的例子，让我们来看一个[更大的应用](../tutorial/bigger-applications.md){.internal-link target=_blank}和[测试](../tutorial/testing.md){.internal-link target=_blank}中描述的类似文件结构：

```
.
├── app
│   ├── __init__.py
│   ├── main.py
│   └── test_main.py
```

final class Internal {

  /**
   * Returns the number of nanoseconds of the given duration without throwing or overflowing.
   *
   * <p>Instead of throwing {@link ArithmeticException}, this method silently saturates to either
   * {@link Long#MAX_VALUE} or {@link Long#MIN_VALUE}. This behavior can be useful when decomposing
   * a duration in order to call a legacy API which requires a {@code long, TimeUnit} pair.
   */

/**
 * The {@code CycleDetectingLockFactory} creates {@link ReentrantLock} instances and {@link
 * ReentrantReadWriteLock} instances that detect potential deadlock by checking for cycles in lock
 * acquisition order.
 *
 * <p>Potential deadlocks detected when calling the {@code lock()}, {@code lockInterruptibly()}, or
 * {@code tryLock()} methods will result in the execution of the {@link Policy} specified when

          Iterator<E> iterator = collection.iterator();
          assertTrue(collection.add(e3()));
          iterator.next();
        });
  }

  /**
   * Returns the {@link Method} instance for {@link #testAdd_nullSupported()} so that tests of
   * {@link java.util.Collections#checkedCollection(java.util.Collection, Class)} can suppress it
   * with {@code FeatureSpecificTestSuiteBuilder.suppressing()} until <a