# ADR-0008 - Use NullAway for null checking

## Date

2025-08-06

## Context

Our codebase uses `null` extensively to represent an absence of value or optionality of the argument.
We utilize nullness annotations in Java code and somewhat rely on IDE warnings to guide us.
However, the Java code we have is not fully annotated, which causes several consequences:
* IDE warnings can be misleading

    assertEscaping(e, "%00", '\u0000'); // nul
    assertEscaping(e, "%7F", '\u007f'); // del
    assertEscaping(e, "%C2%80", '\u0080'); // xx-00010,x-000000
    assertEscaping(e, "%DF%BF", '\u07ff'); // xx-11111,x-111111
    assertEscaping(e, "%E0%A0%80", '\u0800'); // xxx-0000,x-100000,x-00,0000
    assertEscaping(e, "%EF%BF%BF", '\uffff'); // xxx-1111,x-111111,x-11,1111
    assertUnicodeEscaping(e, "%F0%90%80%80", '\uD800', '\uDC00');

    void setCreateTime(long time) throws CIFSException;

    /**
     * Retrieve the last acces time of the file represented by this <code>SmbResource</code>
     *
     * @return The number of milliseconds since the 00:00:00 GMT, January 1,
     *         1970 as a <code>long</code> value
     * @throws CIFSException if an error occurs accessing the resource
     */
    long lastAccess() throws CIFSException;

    /**

* `--bind`: 구니콘이 관찰할 IP와 포트를 의미합니다. 콜론 (`:`)을 사용하여 IP와 포트를 구분합니다.
    * 만약에 `--bind 0.0.0.0:80` (구니콘 옵션) 대신 유비콘을 직접 실행하고 싶다면 `--host 0.0.0.0`과 `--port 80`을 사용해야 합니다.

출력에서 각 프로세스에 대한 **PID** (process ID)를 확인할 수 있습니다. (단순한 숫자입니다)

출력 내용:

* 구니콘 **프로세스 매니저**는 PID `19499`로 실행됩니다. (직접 실행할 경우 숫자가 다를 수 있습니다)
* 다음으로 `Listening at: http://0.0.0.0:80`을 시작합니다.
* 그런 다음 사용해야할 `uvicorn.workers.UvicornWorker`의 워커클래스를 탐지합니다.

        // Credit charge
        SMBUtil.writeInt2(1, buffer, headerStart + 6);
        // Status
        SMBUtil.writeInt4(0, buffer, headerStart + 8);
        // Command (READ = 0x0008)
        SMBUtil.writeInt2(0x0008, buffer, headerStart + 12);
        // Credit request/response
        SMBUtil.writeInt2(1, buffer, headerStart + 14);
        // Flags
        SMBUtil.writeInt4(0, buffer, headerStart + 16);

            // When/Then
            Method getResultMessageMethod = DcerpcBind.class.getDeclaredMethod("getResultMessage", int.class);
            getResultMessageMethod.setAccessible(true);

            assertEquals("0x0004", getResultMessageMethod.invoke(null, 4), "Should return hex format for unknown code 4");
            assertEquals("0x00FF", getResultMessageMethod.invoke(null, 255), "Should return hex format for unknown code 255");

        assertTrue(result.contains("maxBufferSize=4096"));
        assertTrue(result.contains("maxRawSize=8192"));
        assertTrue(result.contains("sessionKey=0x00ABCDEF"));
        // CAP_UNICODE is 0x0004, when formatted as 8 hex digits = 0x00000004
        assertTrue(result.contains("capabilities=0x00000004"));
        assertTrue(result.contains("serverTime=" + new Date(serverData.serverTime)));

        assertEquals((short) 0x0005, SmbComTransaction.TRANS2_QUERY_PATH_INFORMATION);
        assertEquals((short) 0x0007, SmbComTransaction.TRANS2_QUERY_FILE_INFORMATION);
        assertEquals((short) 0x0008, SmbComTransaction.TRANS2_SET_FILE_INFORMATION);
        assertEquals((short) 0x0010, SmbComTransaction.TRANS2_GET_DFS_REFERRAL);
    }

    @Test
    @DisplayName("Test encode and decode operations")

      .isEqualTo(0L)
    assertThat(parse(url, "a=b; Expires=Thu, 01 Jan 1970 00:00:0 GMT")!!.expiresAt)
      .isEqualTo(0L)
    assertThat(parse(url, "a=b; Expires=00:00:00 Thu, 01 Jan 1970 GMT")!!.expiresAt)
      .isEqualTo(0L)
    assertThat(parse(url, "a=b; Expires=00:00:00 1970 Jan 01")!!.expiresAt)
      .isEqualTo(0L)

		// the behavior is verified by researching the source code.
		//
		//	$ bsdtar -tvf pax-global-records.tar
		//	----------  0 0      0           0 Dec 31  1969 file1
		//	----------  0 0      0           0 Dec 31  1969 file2
		//	----------  0 0      0           0 Dec 31  1969 file3
		//	----------  0 0      0           0 May 13  2014 file4
		//
		// GNU tar v1.27.1 applies global headers to subsequent records,