MybatisPlus生成器ServiceImpl类详解

1年前 (2023) 程序员胖胖胖虎阿
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ServiceImpl类是我们进行SQL操作中非常重要的一个类,通过MybatisPlus生成的各个实体类的XXXImpl都会继承ServiceImpl类那里继承全部的方法,那么ServiceImpl类中有哪些方法呢?如下介绍:


/**
 * IService 实现类( 泛型:M 是 mapper 对象,T 是实体 )
 *
 * @author hubin
 * @since 2018-06-23
 */
@SuppressWarnings("unchecked")
public class ServiceImpl<M extends BaseMapper<T>, T> implements IService<T> {

    protected Log log = LogFactory.getLog(getClass());

    @Autowired
    protected M baseMapper;

    @Override
    public M getBaseMapper() {
        return baseMapper;
    }

    protected Class<T> entityClass = currentModelClass();

    @Override
    public Class<T> getEntityClass() {
        return entityClass;
    }

    protected Class<T> mapperClass = currentMapperClass();

    /**
     * 判断数据库操作是否成功
     *
     * @param result 数据库操作返回影响条数
     * @return boolean
     * @deprecated 3.3.1
     */
    @Deprecated
    protected boolean retBool(Integer result) {
        return SqlHelper.retBool(result);
    }

    protected Class<T> currentMapperClass() {
        return (Class<T>) ReflectionKit.getSuperClassGenericType(getClass(), 0);
    }

    protected Class<T> currentModelClass() {
        return (Class<T>) ReflectionKit.getSuperClassGenericType(getClass(), 1);
    }

    /**
     * 批量操作 SqlSession
     *
     * @deprecated 3.3.0
     */
    @Deprecated
    protected SqlSession sqlSessionBatch() {
        return SqlHelper.sqlSessionBatch(entityClass);
    }

    /**
     * 释放sqlSession
     *
     * @param sqlSession session
     * @deprecated 3.3.0
     */
    @Deprecated
    protected void closeSqlSession(SqlSession sqlSession) {
        SqlSessionUtils.closeSqlSession(sqlSession, GlobalConfigUtils.currentSessionFactory(entityClass));
    }

    /**
     * 获取 SqlStatement
     *
     * @param sqlMethod ignore
     * @return ignore
     * @see #getSqlStatement(SqlMethod)
     * @deprecated 3.4.0
     */
    @Deprecated
    protected String sqlStatement(SqlMethod sqlMethod) {
        return SqlHelper.table(entityClass).getSqlStatement(sqlMethod.getMethod());
    }

    /**
     * 批量插入
     *
     * @param entityList ignore
     * @param batchSize  ignore
     * @return ignore
     */
    @Transactional(rollbackFor = Exception.class)
    @Override
    public boolean saveBatch(Collection<T> entityList, int batchSize) {
        String sqlStatement = getSqlStatement(SqlMethod.INSERT_ONE);
        return executeBatch(entityList, batchSize, (sqlSession, entity) -> sqlSession.insert(sqlStatement, entity));
    }

    /**
     * 获取mapperStatementId
     *
     * @param sqlMethod 方法名
     * @return 命名id
     * @since 3.4.0
     */
    protected String getSqlStatement(SqlMethod sqlMethod) {
        return SqlHelper.getSqlStatement(mapperClass, sqlMethod);
    }

    /**
     * TableId 注解存在更新记录,否插入一条记录
     *
     * @param entity 实体对象
     * @return boolean
     */
    @Transactional(rollbackFor = Exception.class)
    @Override
    public boolean saveOrUpdate(T entity) {
        if (null != entity) {
            TableInfo tableInfo = TableInfoHelper.getTableInfo(this.entityClass);
            Assert.notNull(tableInfo, "error: can not execute. because can not find cache of TableInfo for entity!");
            String keyProperty = tableInfo.getKeyProperty();
            Assert.notEmpty(keyProperty, "error: can not execute. because can not find column for id from entity!");
            Object idVal = ReflectionKit.getFieldValue(entity, tableInfo.getKeyProperty());
            return StringUtils.checkValNull(idVal) || Objects.isNull(getById((Serializable) idVal)) ? save(entity) : updateById(entity);
        }
        return false;
    }

    @Transactional(rollbackFor = Exception.class)
    @Override
    public boolean saveOrUpdateBatch(Collection<T> entityList, int batchSize) {
        TableInfo tableInfo = TableInfoHelper.getTableInfo(entityClass);
        Assert.notNull(tableInfo, "error: can not execute. because can not find cache of TableInfo for entity!");
        String keyProperty = tableInfo.getKeyProperty();
        Assert.notEmpty(keyProperty, "error: can not execute. because can not find column for id from entity!");
        return SqlHelper.saveOrUpdateBatch(this.entityClass, this.mapperClass, this.log, entityList, batchSize, (sqlSession, entity) -> {
            Object idVal = ReflectionKit.getFieldValue(entity, keyProperty);
            return StringUtils.checkValNull(idVal)
                || CollectionUtils.isEmpty(sqlSession.selectList(getSqlStatement(SqlMethod.SELECT_BY_ID), entity));
        }, (sqlSession, entity) -> {
            MapperMethod.ParamMap<T> param = new MapperMethod.ParamMap<>();
            param.put(Constants.ENTITY, entity);
            sqlSession.update(getSqlStatement(SqlMethod.UPDATE_BY_ID), param);
        });
    }

    @Transactional(rollbackFor = Exception.class)
    @Override
    public boolean updateBatchById(Collection<T> entityList, int batchSize) {
        String sqlStatement = getSqlStatement(SqlMethod.UPDATE_BY_ID);
        return executeBatch(entityList, batchSize, (sqlSession, entity) -> {
            MapperMethod.ParamMap<T> param = new MapperMethod.ParamMap<>();
            param.put(Constants.ENTITY, entity);
            sqlSession.update(sqlStatement, param);
        });
    }

    @Override
    public T getOne(Wrapper<T> queryWrapper, boolean throwEx) {
        if (throwEx) {
            return baseMapper.selectOne(queryWrapper);
        }
        return SqlHelper.getObject(log, baseMapper.selectList(queryWrapper));
    }

    @Override
    public Map<String, Object> getMap(Wrapper<T> queryWrapper) {
        return SqlHelper.getObject(log, baseMapper.selectMaps(queryWrapper));
    }

    @Override
    public <V> V getObj(Wrapper<T> queryWrapper, Function<? super Object, V> mapper) {
        return SqlHelper.getObject(log, listObjs(queryWrapper, mapper));
    }

    /**
     * 执行批量操作
     *
     * @param consumer consumer
     * @since 3.3.0
     * @deprecated 3.3.1 后面我打算移除掉 {@link #executeBatch(Collection, int, BiConsumer)} }.
     */
    @Deprecated
    protected boolean executeBatch(Consumer<SqlSession> consumer) {
        return SqlHelper.executeBatch(this.entityClass, this.log, consumer);
    }

    /**
     * 执行批量操作
     *
     * @param list      数据集合
     * @param batchSize 批量大小
     * @param consumer  执行方法
     * @param <E>       泛型
     * @return 操作结果
     * @since 3.3.1
     */
    protected <E> boolean executeBatch(Collection<E> list, int batchSize, BiConsumer<SqlSession, E> consumer) {
        return SqlHelper.executeBatch(this.entityClass, this.log, list, batchSize, consumer);
    }

    /**
     * 执行批量操作(默认批次提交数量{@link IService#DEFAULT_BATCH_SIZE})
     *
     * @param list     数据集合
     * @param consumer 执行方法
     * @param <E>      泛型
     * @return 操作结果
     * @since 3.3.1
     */
    protected <E> boolean executeBatch(Collection<E> list, BiConsumer<SqlSession, E> consumer) {
        return executeBatch(list, DEFAULT_BATCH_SIZE, consumer);
    }

}

ServiceImpl类各方法(未过期)的作用

  1. getBaseMapper()
  2. getEntityClass()
  3. saveBatch()
  4. saveOrUpdate()
  5. saveOrUpdateBatch()
  6. updateBatchById()
  7. getOne()
  8. getMap()
  9. getObj()

ServiceImpl类各属性的作用

  1. log:打印日志
  2. baseMapper:实现了许多的SQL操作
  3. entityClass:实体类
  4. mapperClass:映射类

BaseMapper类中各方法

ServiceImpl类中有这个类的成员变量,因此通过ServiceImpl这个类便能够操作如下方法:

  1. int insert(T entity);:插入记录
  2. int deleteById(Serializable id);:通过id删除指定记录
  3. int deleteByMap(Map<String, Object> columnMap):通过Map集合添加删除指定记录
  4. int delete(@Param(Constants.WRAPPER) Wrapper queryWrapper):通过添加构造器删除指定记录
  5. int deleteBatchIds(Collection<? extends Serializable> idList):通过List集合批量删除记录
  6. int updateById(T entity):根据id修改指定记录
  7. int update(T entity, Wrapper updateWrapper):根据条件构造器
  8. T selectById(Serializable id):根据id查询指定记录
  9. List selectBatchIds(Collection<? extends Serializable> idList):根据List集合批量查询记录
  10. List selectByMap(Map<String, Object> columnMap):根据Map集合查询记录
  11. T selectOne(Wrapper queryWrapper):根据条件构造器查询一条记录
  12. Integer selectCount(Wrapper queryWrapper):根据条件构造器查询记录总数
  13. List selectList(Wrapper queryWrapper):根据条件构造器查询全部记录
  14. List<Map<String, Object>> selectMaps(Wrapper queryWrapper):根据条件构造器查询全部记录
  15. ist selectObjs(Wrapper queryWrapper):根据条件构造器查询全部记录
  16. <E extends IPage> E selectPage(E page, Wrapper queryWrapper):根据条件构造器查询全部记录(并翻页)
  17. <E extends IPage<Map<String, Object>>> E selectMapsPage(E page, Wrapper queryWrapper):根据条件构造器查询全部记录(并翻页)

Wrapper类各方法

  1. getEntity():实体对象(子类实现)
  2. getSqlSelectgetSqlSet():
  3. getSqlComment():
  4. getSqlFirst():
  5. getExpression():获取 MergeSegments
  6. getCustomSqlSegment():获取自定义SQL 简化自定义XML复杂情况
  7. isEmptyOfWhere():查询条件为空(包含entity)
  8. nonEmptyOfWhere():查询条件不为空(包含entity)
  9. isEmptyOfNormal():查询条件为空(不包含entity)
  10. nonEmptyOfNormal():查询条件为空(不包含entity)
  11. nonEmptyOfEntity():深层实体判断属性
  12. fieldStrategyMatch():根据实体FieldStrategy属性来决定判断逻辑
  13. isEmptyOfEntity():深层实体判断属性
  14. getTargetSql():获取格式化后的执行sql
  15. clear():条件清空

实例说明

public class ServiceImpl<M extends BaseMapper<T>, T> implements IService<T> {}

public class CategoryServiceImpl extends ServiceImpl<CategoryDao, CategoryEntity> implements CategoryService {}

在ServiceImpl中已经注入了Mapper对象: protected M baseMapper;因此XXXServiceImpl只要继承了这个原生的ServiceImpl,这个M实体Dao就已经注入了进来,不需要重新注入。

版权声明:程序员胖胖胖虎阿 发表于 2023年3月20日 下午10:24。
转载请注明:MybatisPlus生成器ServiceImpl类详解 | 胖虎的工具箱-编程导航

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