sql注入器

• ​​官方文档​​
• ​​官方案例​​
• SQL 自动注入器接口 ISqlInjector

public interface ISqlInjector {

    /**
     * <p>
     * 检查SQL是否注入(已经注入过不再注入)
     * </p>
     *
     * @param builderAssistant mapper 信息
     * @param mapperClass      mapper 接口的 class 对象
     */
    void inspectInject(MapperBuilderAssistant builderAssistant, Class<?> mapperClass);
}

• AbstractSqlInjector实现了ISqlInjector接口

public abstract class AbstractSqlInjector implements ISqlInjector {
    protected final Log logger = LogFactory.getLog(this.getClass());

    public AbstractSqlInjector() {
    }

    public void inspectInject(MapperBuilderAssistant builderAssistant, Class<?> mapperClass) {
        Class<?> modelClass = ReflectionKit.getSuperClassGenericType(mapperClass, Mapper.class, 0);
        if (modelClass != null) {
            String className = mapperClass.toString();
            Set<String> mapperRegistryCache = GlobalConfigUtils.getMapperRegistryCache(builderAssistant.getConfiguration());
            if (!mapperRegistryCache.contains(className)) {
                TableInfo tableInfo = TableInfoHelper.initTableInfo(builderAssistant, modelClass);
                List<AbstractMethod> methodList = this.getMethodList(mapperClass, tableInfo);
                if (CollectionUtils.isNotEmpty(methodList)) {
                    methodList.forEach((m) -> {
                        m.inject(builderAssistant, mapperClass, modelClass, tableInfo);
                    });
                } else {
                    this.logger.debug(mapperClass.toString() + ", No effective injection method was found.");
                }

                mapperRegistryCache.add(className);
            }
        }

    }

    public abstract List<AbstractMethod> getMethodList(Class<?> mapperClass, TableInfo tableInfo);
}

• DefaultSqlInjector继承了AbstractSqlInjector抽象类

public class DefaultSqlInjector extends AbstractSqlInjector {
    public DefaultSqlInjector() {
    }

    public List<AbstractMethod> getMethodList(Class<?> mapperClass, TableInfo tableInfo) {
        Builder<AbstractMethod> builder = Stream.builder().add(new Insert()).add(new Delete()).add(new DeleteByMap()).add(new Update()).add(new SelectByMap()).add(new SelectCount()).add(new SelectMaps()).add(new SelectMapsPage()).add(new SelectObjs()).add(new SelectList()).add(new SelectPage());
        if (tableInfo.havePK()) {
            builder.add(new DeleteById()).add(new DeleteBatchByIds()).add(new UpdateById()).add(new SelectById()).add(new SelectBatchByIds());
        } else {
            this.logger.warn(String.format("%s ,Not found @TableId annotation, Cannot use Mybatis-Plus 'xxById' Method.", tableInfo.getEntityType()));
        }

        return (List)builder.build().collect(Collectors.toList());
    }
}

• 自定义自己的通用方法可以实现接口 ISqlInjector 也可以继承抽象类 AbstractSqlInjector 注入通用方法 SQL 语句 然后继承 BaseMapper 添加自定义方法，全局配置 sqlInjector 注入 MP 会自动将类所有方法注入到 mybatis 容器中
• 例如自定义1个删除全部的通用方法
• 第1步，定义sql

public class DeleteAll extends AbstractMethod {

    @Override
    public MappedStatement injectMappedStatement(Class<?> mapperClass, Class<?> modelClass, TableInfo tableInfo) {
        /* 执行 SQL ，动态 SQL 参考类 SqlMethod */
        String sql = "delete from " + tableInfo.getTableName();
        /* mapper 接口方法名一致 */
        String method = "deleteAll";
        SqlSource sqlSource = languageDriver.createSqlSource(configuration, sql, modelClass);
        return this.addDeleteMappedStatement(mapperClass, method, sqlSource);
    }
}

• 第2步，注册自定义的方法

public class MyLogicSqlInjector extends DefaultSqlInjector {

    /**
     * 如果只需增加方法，保留MP自带方法
     * 可以super.getMethodList() 再add
     * @return
     */
    @Override
    public List<AbstractMethod> getMethodList(Class<?> mapperClass, TableInfo tableInfo) {
        List<AbstractMethod> methodList = super.getMethodList(mapperClass, tableInfo);
        methodList.add(new DeleteAll());
        methodList.add(new MyInsertAll());
        methodList.add(new MysqlInsertAllBatch());
        methodList.add(new SelectById());
        return methodList;
    }
}

• 第3步，把方法定义到BaseMapper

public interface MyBaseMapper<T> extends BaseMapper<T> {

    /**
     * 自定义通用方法
     */
    Integer deleteAll();

    int myInsertAll(T entity);

    /**
     * 如果要自动填充，@{@code Param}(xx) xx参数名必须是 list/collection/array 3个的其中之一
     *
     * @param batchList
     * @return
     */
    int mysqlInsertAllBatch(@Param("list") List<T> batchList);
}

• 测试

@SpringBootTest
class DeluxeTest {

    @Resource
    private UserMapper mapper;

    /**
     * 使用自定义的通用方法
     * delete from user
     */
    @Test
    void testDelAll() {
        mapper.deleteAll();
    }

}