*
 * @author Jon Noack
 */
@GwtIncompatible
final class CompactHashing {
  private CompactHashing() {}

  /** Indicates blank table entries. */
  static final byte UNSET = 0;

  /** Number of bits used to store the numbers of hash table bits (max 30). */
  private static final int HASH_TABLE_BITS_MAX_BITS = 5;

  /** Use high bits of metadata for modification count. */

            throw new UncheckedIOException(e);
        }
    }

    /**
     * Returns {@code true} if passed in artifact is originating from local repository. In other words, we want
     * to process and store tracking information ONLY into local repository, not to any other place. This method
     * filters out currently built artifacts, as events are fired for them as well, but their resolved artifact

     * @since 4.1.0
     */
    @Config(type = "java.lang.Boolean", defaultValue = "true")
    public static final String MAVEN_DEPLOY_BUILD_POM = "maven.deploy.buildPom";

    /**
     * User property used to store the build timestamp.
     *
     * @since 4.0.0
     */
    @Config(type = "java.time.Instant")
    public static final String MAVEN_START_INSTANT = "maven.startInstant";

    /**

     * @return a stream of problems with the specified severity
     */
    @Nonnull
    Stream<P> problems(BuilderProblem.Severity severity);

    /**
     * Creates an "empty" problem collector that doesn't store any problems.
     *
     * @param <P> the type of problem
     * @return an empty problem collector
     */
    @Nonnull
    static <P extends BuilderProblem> ProblemCollector<P> empty() {

# Lifespan Events { #lifespan-events }

You can define logic (code) that should be executed before the application **starts up**. This means that this code will be executed **once**, **before** the application **starts receiving requests**.

The same way, you can define logic (code) that should be executed when the application is **shutting down**. In this case, this code will be executed **once**, **after** having handled possibly **many requests**.

import org.apache.maven.execution.DefaultMavenExecutionResult;
import org.apache.maven.execution.MavenSession;
import org.apache.maven.impl.InternalSession;
import org.apache.maven.impl.resolver.scopes.Maven4ScopeManagerConfiguration;
import org.apache.maven.internal.impl.DefaultLookup;
import org.apache.maven.internal.impl.DefaultSession;
import org.apache.maven.internal.impl.InternalMavenSession;

        validate(form, messages -> {}, this::asEditHtml);
        verifyToken(this::asEditHtml);
        createSynonymItem(form, this::asEditHtml).ifPresent(entity -> {
            try {
                synonymService.store(form.dictId, entity);
                saveInfo(messages -> messages.addSuccessCrudCreateCrudTable(GLOBAL));
            } catch (final Exception e) {
                logger.warn("Failed to process a request.", e);

但由于这种用例很常见，FastAPI 为了简便，就直接提供了对它的支持。

///

### 使用表单数据 { #use-the-form-data }

/// tip | 提示

`OAuth2PasswordRequestForm` 类依赖项的实例没有以空格分隔的长字符串属性 `scope`，但它支持 `scopes` 属性，由已发送的 scope 字符串列表组成。

本例没有使用 `scopes`，但开发者也可以根据需要使用该属性。

///

现在，即可使用表单字段 `username`，从（伪）数据库中获取用户数据。

如果不存在指定用户，则返回错误消息，提示**用户名或密码错误**。

本例使用 `HTTPException` 异常显示此错误：

    @Test
    public void test_add_whitespaceInName() {
        TestScriptEngine engine = new TestScriptEngine();
        scriptEngineFactory.add("  test  ", engine);

        // Should be stored with lowercase and original spaces
        ScriptEngine retrieved = scriptEngineFactory.getScriptEngine("  test  ");
        assertNotNull(retrieved);
        assertEquals(engine, retrieved);
    }

  }

  /*
   * We don't define getPredecessor+getSuccessor and setPredecessor+setSuccessor here because
   * they're defined above -- including logic to add and subtract 1 to map between the values stored
   * in the predecessor/successor arrays and the indexes in the elements array that they identify.
   */