* Provides functionality to store, retrieve, and manage failed crawling attempts
 * with their associated error information.
 */
public class FailureUrlService {

    /** Logger instance for this class */
    private static final Logger logger = LogManager.getLogger(FailureUrlService.class);

    /**
     * Default constructor.
     */
    public FailureUrlService() {
        // Default constructor

        return LabelType.class;
    }

    // ===================================================================================
    //                                                                     Object Instance
    //                                                                     ===============
    @Override
    public Entity newEntity() {
        return new LabelType();
    }

   * delegates each of its operations to the appropriate methods of this {@code
   * ForwardingSortedMultiset}.
   *
   * <p>In many cases, you may wish to override {@link #descendingMultiset()} to return an instance
   * of a subclass of {@code StandardDescendingMultiset}.
   *
   * @since 15.0
   */
  protected abstract class StandardDescendingMultiset extends DescendingMultiset<E> {
    /** Constructor for use by subclasses. */

      thrownReflectionFailure = reflectionFailure;
      helper = new SynchronizedAtomicHelper();
    }
    ATOMIC_HELPER = helper;
    // Log after all static init is finished; if an installed logger uses any Futures methods, it
    // shouldn't break in cases where reflection is missing/broken.
    if (thrownReflectionFailure != null) {

    }

    /**
     * Returns a filter for directories that may contain paths accepted by the given matcher.
     * The given path matcher should be an instance created by this service.
     * The path matcher returned by this method expects directory paths.
     * If that matcher returns {@code false}, then the directory will definitively not contain

That when called, return instances of classes of the same name.

So, you import `Query`, which is a function. And when you call it, it returns an instance of a class also named `Query`.

These functions are there (instead of just using the classes directly) so that your editor doesn't mark errors about their types.

## 安装 `SQLModel`

首先，确保您创建并激活了[虚拟环境](../virtual-environments.md){.internal-link target=_blank}，然后安装了 `sqlmodel` :

<div class="termy">

```console
$ pip install sqlmodel
---> 100%
```

</div>

## 创建含有单一模型的应用程序

我们首先创建应用程序的最简单的第一个版本，只有一个 **SQLModel** 模型。

稍后我们将通过下面的**多个模型**提高其安全性和多功能性。🤓

### 创建模型

导入 `SQLModel` 并创建一个数据库模型：

        }
    }

    /**
     * Create SmbFile from cached file info
     *
     * @param directoryPath parent directory path
     * @param fileInfo cached file information
     * @return SmbFile instance
     * @throws IOException on error
     */
    private SmbFile createSmbFileFromCache(String directoryPath, DirectoryCacheEntry.FileInfo fileInfo) throws IOException {
        String filePath = directoryPath;

    private FileNotifyInformationImpl notifyInfo;

    @BeforeEach
    void setUp() {
        notifyInfo = new FileNotifyInformationImpl();
    }

    @Test
    @DisplayName("Test default constructor creates instance with null values")
    void testDefaultConstructor() {
        assertNotNull(notifyInfo);
        assertEquals(0, notifyInfo.getAction());
        assertNull(notifyInfo.getFileName());

            is.setEncoding(accessResultData.getEncoding());
        }

        // create handler
        final DocHandler handler = new DocHandler();

        // create a sax instance
        final SAXParserFactory spfactory = SAXParserFactory.newInstance();
        try {
            spfactory.setFeature(Constants.FEATURE_SECURE_PROCESSING, true);