阿超 > byte-buddy实现mybatis-plus动态mapper

byte-buddy实现mybatis-plus动态mapper

2023-01-11

java

掌握了教育，就掌握了国家——法国谚语

构造动态mapper部分代码如下：

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public static void buildMapper(Configuration configuration, Class<?> entityClass) {
    if (!(configuration instanceof MybatisConfiguration)) {
        throw new IllegalArgumentException("configuration must be MybatisConfiguration");
    }
    ENTITY_MAPPER_CLASS_CACHE.computeIfAbsent(entityClass, k -> {
        Class<?> dynamicMapper = new ByteBuddy()
                .makeInterface(TypeDescription.Generic.Builder.parameterizedType(IMapper.class, entityClass).build())
                .name(String.format("io.github.vampireachao.mapper.%sMapper", entityClass.getSimpleName()))
                .make()
                .load(ClassUtils.class.getClassLoader())
                .getLoaded();
        configuration.addMapper(dynamicMapper);
        return dynamicMapper;
    });
}

这里是放到一个map里，获取的地方如下：

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public static <T> Class<?> getMapperClass(Class<T> clazz) {
    if (clazz == null || clazz.isPrimitive() || SimpleTypeRegistry.isSimpleType(clazz) || clazz.isInterface()) {
        throw ExceptionUtils.mpe("找不到指定的class！请仅在明确确定会有 class 的时候，调用该方法");
    }
    Class<?> targetClass = ClassUtils.getUserClass(clazz);
    Class<?> mapperClass = ENTITY_MAPPER_CLASS_CACHE.get(targetClass);
    if (null != mapperClass) {
        return mapperClass;
    }
    Class<?> currentClass = clazz;
    while (null == mapperClass && Object.class != currentClass) {
        currentClass = currentClass.getSuperclass();
        mapperClass = ENTITY_MAPPER_CLASS_CACHE.get(ClassUtils.getUserClass(currentClass));
    }
    if (mapperClass == null) {
        mapperClass = ClassUtils.toClassConfident(getTableInfo(clazz).getCurrentNamespace());
    }
    if (mapperClass != null) {
        ENTITY_MAPPER_CLASS_CACHE.put(targetClass, mapperClass);
    }
    return mapperClass;
}

使用：

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@Test
void testBuildMapper() {
    UserInfo userInfo = new UserInfo() {{
        setId(1L);
        setName("Jone");
    }};
    Configuration configuration = TableInfoHelper.getTableInfo(UserInfo.class).getConfiguration();
    Database.buildMapper(configuration, UserInfo.class);
    TableInfo tableInfo = TableInfoHelper.getTableInfo(userInfo.getClass());
    Assertions.assertNotNull(tableInfo);
    Assertions.assertFalse(Database.list(userInfo.getClass()).isEmpty());
}

完整源码：https://gitee.com/VampireAchao/stream-query