List<TearDown> stackCopy;
    synchronized (lock) {
      stackCopy = Lists.newArrayList(stack);
      stack.clear();
    }
    for (TearDown tearDown : stackCopy) {
      try {
        tearDown.tearDown();
      } catch (Throwable t) {
        if (suppressThrows) {
          logger.log(Level.INFO, "exception thrown during tearDown", t);
        } else {
          exceptions.add(t);
        }

    int writeSetupWireFormat( byte[] dst, int dstIndex ) {
        return 0;
    }
    int writeParametersWireFormat( byte[] dst, int dstIndex ) {
        int start = dstIndex;
        byte[] descr;

        try {
            descr = DESCR.getBytes( "ASCII" );
        } catch( UnsupportedEncodingException uee ) {
            return 0;
        }

        writeInt2( NET_SHARE_ENUM, dst, dstIndex );
        dstIndex += 2;

        String downloadUrl = "http://somewhere.com/download";
        List<String> path = Arrays.asList("dependency1", "dependency2");
        String expected = "Missing artifact" + LS + LS + "  Try downloading the file manually from: " + LS
                + "      http://somewhere.com/download" + LS + LS + "  Then, install it using the command: " + LS

                        "-jar",
                        file.toAbsolutePath().toString(),
                        "5.32",
                        "5.27"
                    });

                    try {
                        assertEquals(0, p.waitFor(), "Unexpected exit code");
                    } catch (InterruptedException e) {
                        throw new InterruptedIOException(e.toString());
                    }

import static org.junit.jupiter.api.Assertions.assertEquals;

class MavenModelVersionTest {

    private static Model model;

    @BeforeAll
    static void setup() throws Exception {
        try (InputStream is = MavenModelVersionTest.class.getResourceAsStream("/xml/pom.xml")) {
            model = new MavenStaxReader().read(is);
        }
    }

    @Test
    void testV4Model() {

    List<TearDown> stackCopy;
    synchronized (lock) {
      stackCopy = Lists.newArrayList(stack);
      stack.clear();
    }
    for (TearDown tearDown : stackCopy) {
      try {
        tearDown.tearDown();
      } catch (Throwable t) {
        if (suppressThrows) {
          logger.log(Level.INFO, "exception thrown during tearDown", t);
        } else {
          exceptions.add(t);
        }

  }

  @Override
  public boolean ready() throws IOException {
    return (current != null) && current.ready();
  }

  @Override
  public void close() throws IOException {
    if (current != null) {
      try {
        current.close();
      } finally {
        current = null;
      }
    }
  }

            throw new CrawlingAccessException("No response body.");
        }

        final ResultData resultData = new ResultData();
        resultData.setTransformerName(getName());

        try (BufferedInputStream bis = new BufferedInputStream(responseData.getResponseBody())) {
            resultData.setData(IOUtils.toByteArray(bis));
            resultData.setEncoding(responseData.getCharSet());

Sie können `async`hrone oder reguläre Funktionen verwenden.

**FastAPI** wird bei jeder das Richtige tun, so wie auch bei normalen Abhängigkeiten.

///

## Eine Abhängigkeit mit `yield` und `try`.

Wenn Sie einen `try`-Block in einer Abhängigkeit mit `yield` verwenden, empfangen Sie alle Exceptions, die bei Verwendung der Abhängigkeit geworfen wurden.

```Python hl_lines="5-6"
{!../../docs_src/dependencies/tutorial007.py!}
```

/// tip | 提示

你可以使用 `async` 或普通函数。

**FastAPI** 会像处理普通依赖一样，对每个依赖做正确的处理。

///

## 包含 `yield` 和 `try` 的依赖项

如果在包含 `yield` 的依赖中使用 `try` 代码块，你会捕获到使用依赖时抛出的任何异常。

例如，如果某段代码在另一个依赖中或在 *路由函数* 中使数据库事务"回滚"或产生任何其他错误，你将会在依赖中捕获到异常。

因此，你可以使用 `except SomeException` 在依赖中捕获特定的异常。

同样，你也可以使用 `finally` 来确保退出步骤得到执行，无论是否存在异常。