1. 3層パッケージ構成と Shading

MyBatis 3 (v3.6.0) は src/main/java/org/apache/ibatis/ 配下の 20 パッケージに 393 Java ソースファイル（23,364 LOC、374 クラス、2,721 メソッド）を編成しています。全20パッケージに package-info.java（20/20）が整備されており、Java モジュール名 Automatic-Module-Name: org.mybatis および OSGi バンドルヘッダを公開しています。

01_package_and_layers_1
MyBatis 3 v3.6.0 — 3つのアーキテクチャ層に分類された全20パッケージ
Source Code 
from drawlib.canvas import save, setup
from drawlib.icons import phosphor
from drawlib.smartarts import CardList, Panel
from drawlib.styles import Colors, Styles

setup(width=144, height=66, dpi=150)

white_card = Styles.Neutral.patch(shape_fill_color=Colors.White)

t1_panel = Panel(
    "Tier 1: Public API",
    "5 Packages · 78 Files",
    style=Styles.Neutral,
    header_style=Styles.PrimaryNeutral.patch(shape_line_width=1.2),
    text_style=Styles.DarkBold.patch(text_size=10.5),
    description_style=Styles.Muted.patch(text_size=9.2),
    icon=phosphor.stack,
    icon_style=Styles.PrimaryBold,
    header_variant="filled",
    header_height=7.8,
)
t1_panel.draw((3.5, 4.5), width=43.5, height=57.0, align="bottom_left")
xy1, w1, h1 = t1_panel.get_content_box((3.5, 4.5), width=43.5, height=57.0, padding=(2.2, 2.2), align="bottom_left")

c1 = CardList(
    style=white_card,
    text_style=Styles.DarkBold.patch(text_size=9.8),
    description_style=Styles.Muted.patch(text_size=9.2),
    badge_shape="rounded_rect",
    badge_style=Styles.PrimaryFlat,
    badge_text_style=Styles.WhiteBold.patch(text_size=9.2),
    direction="vertical",
    spacing=1.8,
)
c1.add("session (17)", "SqlSession & Configuration", badge_text="T1")
c1.add("binding (6)", "MapperRegistry & Proxy", badge_text="T1")
c1.add("annotations (39)", "@Select, @Results, @Param", badge_text="T1")
c1.add("cursor & jdbc (16)", "Cursor<T>, SQL, SqlRunner", badge_text="T1")
c1.draw(xy1, width=w1, height=h1, align="bottom_left")

t2_panel = Panel(
    "Tier 2: Execution Core",
    "5 Packages · 133 Files",
    style=Styles.Neutral,
    header_style=Styles.SecondaryNeutral.patch(shape_line_width=1.2),
    text_style=Styles.DarkBold.patch(text_size=10.5),
    description_style=Styles.Muted.patch(text_size=9.2),
    icon=phosphor.gear_six,
    icon_style=Styles.DarkBold,
    header_variant="filled",
    header_height=7.8,
)
t2_panel.draw((50.2, 4.5), width=43.5, height=57.0, align="bottom_left")
xy2, w2, h2 = t2_panel.get_content_box((50.2, 4.5), width=43.5, height=57.0, padding=(2.2, 2.2), align="bottom_left")

c2 = CardList(
    style=white_card,
    text_style=Styles.DarkBold.patch(text_size=9.8),
    description_style=Styles.Muted.patch(text_size=9.2),
    badge_shape="rounded_rect",
    badge_style=Styles.SecondaryFlat,
    badge_text_style=Styles.WhiteBold.patch(text_size=9.2),
    direction="vertical",
    spacing=1.8,
)
c2.add("builder (26)", "XML & Annotation Builders", badge_text="T2")
c2.add("mapping (18)", "MappedStatement & ResultMap", badge_text="T2")
c2.add("scripting (25)", "SqlNode AST & OgnlCache", badge_text="T2")
c2.add("executor & plugin (57)", "Executors, Handlers, Plugin", badge_text="T2")
c2.draw(xy2, width=w2, height=h2, align="bottom_left")

t3_panel = Panel(
    "Tier 3: Foundation",
    "10 Packages · 182 Files",
    style=Styles.Neutral,
    header_style=Styles.PrimaryNeutral.patch(shape_line_width=1.2),
    text_style=Styles.DarkBold.patch(text_size=10.5),
    description_style=Styles.Muted.patch(text_size=9.2),
    icon=phosphor.cube,
    icon_style=Styles.PrimaryBold,
    header_variant="filled",
    header_height=7.8,
)
t3_panel.draw((97.0, 4.5), width=43.5, height=57.0, align="bottom_left")
xy3, w3, h3 = t3_panel.get_content_box((97.0, 4.5), width=43.5, height=57.0, padding=(2.2, 2.2), align="bottom_left")

c3 = CardList(
    style=white_card,
    text_style=Styles.DarkBold.patch(text_size=9.8),
    description_style=Styles.Muted.patch(text_size=9.2),
    badge_shape="rounded_rect",
    badge_style=Styles.Dark,
    badge_text_style=Styles.WhiteBold.patch(text_size=9.2),
    direction="vertical",
    spacing=1.8,
)
c3.add("type (74)", "TypeHandlerRegistry & 45+ Types", badge_text="T3")
c3.add("reflection (36)", "MetaObject & Reflector", badge_text="T3")
c3.add("cache & tx (22)", "Perpetual/Lru/Transactional", badge_text="T3")
c3.add("datasource, io, log (50)", "PooledDataSource, VFS, XPath", badge_text="T3")
c3.draw(xy3, width=w3, height=h3, align="bottom_left")

save()

全20パッケージ詳細一覧 (org.apache.ibatis.*)

パッケージ 層 ファイル数 代表クラスとアーキテクチャ上の責務
org.apache.ibatis.session Tier 1 17 SqlSessionFactoryBuilder, SqlSessionFactory, SqlSession, Configuration, RowBounds, ResultHandler, SqlSessionManager
org.apache.ibatis.binding Tier 1 6 MapperRegistry, MapperProxyFactory<T>, MapperProxy<T>, MapperMethod, BindingException
org.apache.ibatis.annotations Tier 1 39 @Select, @Insert, @Update, @Delete, @Results, @Result, @One, @Many, @Param, @Options, @CacheNamespace
org.apache.ibatis.cursor Tier 1 3 Cursor<T>, DefaultCursor<T>（JDBC ResultSet を逐次ストリーム読み出し）
org.apache.ibatis.jdbc Tier 1 13 SQL, AbstractSQL<T>, SqlRunner, ScriptRunner
org.apache.ibatis.builder Tier 2 26 BaseBuilder, MapperBuilderAssistant, SqlSourceBuilder, XMLConfigBuilder, XMLMapperBuilder, XMLStatementBuilder, MapperAnnotationBuilder
org.apache.ibatis.mapping Tier 2 18 MappedStatement, BoundSql, ParameterMapping, ResultMap, ResultMapping, Discriminator, SqlSource, Environment, CacheBuilder
org.apache.ibatis.scripting Tier 2 25 LanguageDriver, XMLLanguageDriver, RawSqlSource, DynamicSqlSource, SqlNode 階層, OgnlCache, DefaultParameterHandler
org.apache.ibatis.executor Tier 2 50 Executor, BaseExecutor, SimpleExecutor, ReuseExecutor, BatchExecutor, CachingExecutor, StatementHandler, ResultSetHandler, KeyGenerator
org.apache.ibatis.plugin Tier 2 7 Interceptor, InterceptorChain, Invocation, Plugin, @Intercepts, @Signature
org.apache.ibatis.type Tier 3 74 TypeHandler<T>, BaseTypeHandler<T>, TypeHandlerRegistry, TypeAliasRegistry, JdbcType、および45種以上の標準ハンドラ
org.apache.ibatis.reflection Tier 3 36 MetaObject, MetaClass, Reflector, DefaultReflectorFactory, ObjectFactory, ObjectWrapper, PropertyTokenizer
org.apache.ibatis.cache Tier 3 15 Cache, CacheKey, PerpetualCache, TransactionalCacheManager、および9種の Decorator キャッシュ（LruCache, SerializedCache, BlockingCache 等）
org.apache.ibatis.datasource Tier 3 15 DataSourceFactory, UnpooledDataSource, PooledDataSource, PooledConnection, PoolState, JndiDataSourceFactory
org.apache.ibatis.transaction Tier 3 7 Transaction, TransactionFactory, JdbcTransaction, ManagedTransaction
org.apache.ibatis.parsing Tier 3 6 XPathParser, XNode, GenericTokenParser, PropertyParser
org.apache.ibatis.io Tier 3 9 Resources, ClassLoaderWrapper, ResolverUtil<T>, VFS, DefaultVFS, SerialFilterChecker
org.apache.ibatis.logging Tier 3 22 Log, LogFactory, ConnectionLogger, PreparedStatementLogger, ResultSetLogger（JDBC ロギング動的プロキシ）
org.apache.ibatis.exceptions Tier 3 4 PersistenceException, TooManyResultsException, ExceptionFactory
org.apache.ibatis.lang Tier 3 2 @UsesJava7, @UsesJava8 内部アノテーション

maven-shade-plugin によるゼロ必須依存パッケージング

pom.xml (pom.xml:115-134, 287-310, 365-411) では、すべての compile スコープ依存に <optional>true</optional> が付与されています。パッケージング時に maven-shade-plugin (v3.6.2) が ognl:ognl:3.4.16 を org.apache.ibatis.ognl.* へ、org.javassist:javassist:3.33.0-GA を org.apache.ibatis.javassist.* へとバイトコードレベルでリロケートして JAR 内に同梱するため、利用側アプリケーションで依存バージョンの競合（Classpath Hell）が発生しません。

01_package_and_layers_2
MyBatis 3 v3.6.0 — Maven Shade によるパッケージ・リロケーションと Optional SPI 境界
Source Code 
from drawlib.canvas import save, setup
from drawlib.diagrams.architecture import ArchitectureDiagram, Node, NodeGroup, PhosphorIcon
from drawlib.styles import Colors, Styles

setup(width=144, height=58, dpi=150)

d = ArchitectureDiagram(
    node_style=Styles.Dark,
    node_text_style=Styles.DarkBold.patch(text_size=9.8),
    edge_style=Styles.Dark.patch(line_width=1.5),
    edge_text_style=Styles.DarkBold.patch(text_size=9.2),
    node_card_style=Styles.Neutral.patch(shape_fill_color=Colors.White),
)

up = d.add(
    NodeGroup(
        "Build-Time Optional Inputs (pom.xml)",
        width=44,
        height=48,
        style=Styles.SecondaryNeutral,
        text_style=Styles.DarkBold.patch(text_size=10.2, halign="left", valign="top"),
    ),
    xy=(4, 5),
)
n_ognl = up.add(Node("ognl:ognl\n3.4.16", icon=PhosphorIcon.CODE, width=34, height=13), xy=(22, 33))
n_jav = up.add(Node("org.javassist\n3.33.0-GA", icon=PhosphorIcon.CPU, width=34, height=13), xy=(22, 14))

jar = d.add(
    NodeGroup(
        "mybatis-3.6.0.jar (0 Mandatory Deps)",
        width=48,
        height=48,
        style=Styles.PrimaryNeutral,
        text_style=Styles.DarkBold.patch(text_size=10.2, halign="left", valign="top"),
    ),
    xy=(52, 5),
)
n_s_ognl = jar.add(
    Node(
        "org.apache.ibatis.ognl.*\n(OgnlCache)",
        icon=PhosphorIcon.SHIELD_CHECK,
        width=40,
        height=13,
        style=Styles.White,
        text_style=Styles.WhiteBold.patch(text_size=9.6),
        card_style=Styles.PrimaryFlat,
    ),
    xy=(24, 33),
)
n_s_jav = jar.add(
    Node(
        "org.apache.ibatis.javassist.*\n(JavassistProxyFactory)",
        icon=PhosphorIcon.SHIELD_CHECK,
        width=40,
        height=13,
        style=Styles.White,
        text_style=Styles.WhiteBold.patch(text_size=9.6),
        card_style=Styles.PrimaryFlat,
    ),
    xy=(24, 14),
)

spi = d.add(
    NodeGroup(
        "Optional Classpath SPIs",
        width=36,
        height=48,
        style=Styles.Neutral,
        text_style=Styles.DarkBold.patch(text_size=10.2, halign="left", valign="top"),
    ),
    xy=(104, 5),
)
n_log = spi.add(Node("SLF4J 2.0 / Log4j2\n/ Reload4j / JUL", icon=PhosphorIcon.TERMINAL_WINDOW, width=28, height=13), xy=(18, 33))
n_drv = spi.add(Node("JDBC Driver &\nHikariCP / Pool", icon=PhosphorIcon.DATABASE, width=28, height=13), xy=(18, 14))

n_ognl.connect(n_s_ognl, label="shade")
n_jav.connect(n_s_jav, label="shade")
n_s_ognl.connect(n_log, label="LogFactory")
n_s_jav.connect(n_drv, label="DataSource")

d.draw(xy=(0, 0))
save()