*            The byte buffer. Must not be {@literal null}.
     * @return The number of bytes read.
     */
    public static int read(final FileChannel channel, final ByteBuffer buffer) {
        assertArgumentNotNull("channel", channel);
        assertArgumentNotNull("buffer", buffer);

        try {
            return channel.read(buffer);
        } catch (final IOException e) {
            throw new IORuntimeException(e);

            // Simulate RDMA read operation
            log.debug("DiSNI RDMA read request: {} bytes from remote address 0x{}", bytesToRead, Long.toHexString(remoteAddress));

            return bytesToRead;

        } catch (Exception e) {
            state = RdmaConnectionState.ERROR;
            throw new IOException("DiSNI RDMA read failed", e);
        }
    }

    @Override

    ByteStreams.skipFully(multi, 20);
    assertEquals(20, multi.read());
  }

  public void testReadSingle_noStackOverflow() throws IOException {
    // https://github.com/google/guava/issues/2996
    // no data, just testing that there's no StackOverflowException
    assertEquals(-1, tenMillionEmptySources().read());
  }

  public void testReadArray_noStackOverflow() throws IOException {

    }

    /**
     * Get maximum read/write size
     *
     * @return maximum read/write size in bytes
     */
    public int getMaxReadWriteSize() {
        return maxReadWriteSize;
    }

    /**
     * Set maximum read/write size
     *
     * @param maxReadWriteSize maximum read/write size in bytes
     */

	if err != nil {
		t.Skipf("skipping test because opening a unixpacket socket failed: %v", err)
	}

	// Start a goroutine for the server to accept one connection
	// and read all the data sent on the connection,
	// reporting the number of bytes read on ch.
	ch := make(chan int, 1)
	var wg sync.WaitGroup
	wg.Add(1)
	go func() {
		defer wg.Done()

		tot := 0
		defer func() {
			ch <- tot
		}()

     * Parses mapping rules in the format: input1,input2,... => output
     *
     * @param updater the mapping updater to use for writing changes, or null for read-only reload
     * @param in the input stream to read the mapping data from
     */
    protected void reload(final MappingUpdater updater, final InputStream in) {
        final Pattern parsePattern = Pattern.compile("(.*)\\s*=>\\s*(.*)\\s*$");

    assertTrue(source.wasStreamOpened());
    assertFalse(source.wasStreamClosed());

    StringWriter writer = new StringWriter();
    char[] buf = new char[64];
    int read;
    while ((read = reader.read(buf)) != -1) {
      writer.write(buf, 0, read);
    }
    reader.close();
    writer.close();

    assertTrue(source.wasStreamClosed());
    assertEquals(STRING, writer.toString());
  }

/// tip

The next sections are **not necessarily "advanced"**.

And it's possible that for your use case, the solution is in one of them.

///

## Read the Tutorial first { #read-the-tutorial-first }

The next sections assume you already read the main [Tutorial - User Guide: Security](../../tutorial/security/index.md){.internal-link target=_blank}.

        // Test with single permission
        testUser.setPermissions(new String[] { "read" });
        String[] permissions = fessUserBean.getPermissions();
        assertEquals(1, permissions.length);
        assertEquals("read", permissions[0]);

        // Test with multiple permissions
        testUser.setPermissions(new String[] { "read", "write", "delete" });
        permissions = fessUserBean.getPermissions();

* `write(data)`: Escreve `data` (`str` ou `bytes`) no arquivo.
* `read(size)`: Lê `size` (`int`) bytes/caracteres do arquivo.
* `seek(offset)`: Vai para o byte na posição `offset` (`int`) no arquivo.
    * Por exemplo, `await myfile.seek(0)` irá para o início do arquivo.
    * Isso é especialmente útil se você executar `await myfile.read()` uma vez e precisar ler o conteúdo novamente.
* `close()`: Fecha o arquivo.