mybatis泛型Dao参考三
使用泛型类简化ibatis系统架构2010-08-10 10:14 2702人阅读 评论(6) 收藏 举报
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jdk1.5的推出为我们带来了枚举、泛型、foreach循环、同步工具包等等好东西。其中，泛型的使用为我们的代码开发提供了很大的简便，简化了我们的代码。
1、设计思路
1）GenericDao泛型类提供所有的增删改查功能；
2）所有的dao在继承GenericDao泛型类拥有自身的增删改查功能，不需再写其他代码。
2、实现GenericDao
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[*]public abstract class GenericDao<T, PK extends Serializable> {
[*]
[*] protected final Logger logger = LoggerFactory.getLogger(getClass());
[*]
[*] public static final String POSTFIX_SELECTBYID = ".selectById";
[*] public static final String POSTFIX_SELECTBYIDS = ".selectByIds";
[*] public static final String POSTFIX_SELECTBYMAP = ".selectByMap";
[*] public static final String POSTFIX_SELECTIDSLIKEBYMAP = ".selectIdsLikeByMap";
[*] public static final String POSTFIX_PKSELECTMAP = ".pkSelectByMap";
[*] public static final String POSTFIX_COUNT = ".count";
[*] public static final String POSTFIX_COUNTLIKEBYMAP = ".countLikeByMap";
[*] public static final String POSTFIX_INSERT = ".insert";
[*] public static final String POSTFIX_DELETEBYID = ".deleteById";
[*] public static final String POSTFIX_DELETEBYIDS = ".deleteByIds";
[*] public static final String POSTFIX_DELETEBYIDSMAP = ".deleteByIdsMap";
[*] public static final String POSTFIX_DELETEBYMAP = ".deleteByMap";
[*] public static final String POSTFIX_UPDATE = ".update";
[*] public static final String POSTFIX_UPDATEBYMAP = ".updateByMap";
[*] public static final String POSTFIX_UPDATEBYIDSMAP = ".updateByIdsMap";
[*]
[*] protected Class<T> clazz;
[*]
[*] protected String clazzName;
[*]
[*] protected T t;
[*]
[*] // 定义主从数据库服务器，主数据库负责（Write op），从数据库负责（read op）
[*] @Autowired
[*] protected SqlMapClientTemplate masterSqlMapClientTemplate;
[*]
[*] @Autowired
[*] protected SqlMapClientTemplate slaveSqlMapClientTemplate;
[*]
[*] public GenericDao() {
[*] // 通过范型反射，取得在子类中定义的class.
[*] clazz = (Class<T>) ((ParameterizedType) getClass().getGenericSuperclass()).getActualTypeArguments()[0];
[*] clazzName = clazz.getSimpleName();
[*] }
[*]
[*] public Integer count(String propertyName, Object propertyValue) {
[*] return count(new String[]{propertyName},new Object[]{propertyValue});
[*] }
[*]
[*] public Integer count(String[] propertyNames, Object[] propertyValues) {
[*]
[*] Map<String, Object> map = new HashMap<String, Object>();
[*] for (int i = 0; i < propertyNames.length; i++) {
[*] map.put(propertyNames, propertyValues);
[*] }
[*] return (Integer) slaveSqlMapClientTemplate.queryForObject(clazz.getName() + POSTFIX_COUNT, map);
[*] }
[*]
[*] @Override
[*] public Integer countLikeByMap(String[] propertyNames, Object[] propertyValues) {
[*] Map<String, Object> map = new HashMap<String, Object>();
[*] for (int i = 0; i < propertyNames.length; i++) {
[*] map.put(propertyNames, propertyValues);
[*] }
[*] return (Integer) slaveSqlMapClientTemplate.queryForObject(clazz.getName() + POSTFIX_COUNTLIKEBYMAP, map);
[*] }
[*]
[*] /** 根据自定义SqlMap中的条件语句查询出记录数量 */
[*] public Integer countByStatementPostfix(String statementPostfix,String[] properties, Object[] propertyValues){
[*] Map<String, Object> map = new HashMap<String, Object>();
[*] for (int i = 0; i < properties.length; i++) {
[*] map.put(properties, propertyValues);
[*] }
[*] return (Integer) slaveSqlMapClientTemplate.queryForObject(clazz.getName() + statementPostfix, map);
[*] }
[*] /**
[*] * 通过id得到实体对象
[*] */
[*] public T findById(PK id) {
[*] return (T) slaveSqlMapClientTemplate.queryForObject(clazz.getName() + POSTFIX_SELECTBYID, id);
[*]
[*] }
[*]
[*] /**
[*] * 根据ids获取实体列表
[*] *
[*] * @param ids
[*] * @return
[*] */
[*] public List<T> findByIds(List<PK> ids) {
[*] return (List<T>) slaveSqlMapClientTemplate.queryForList(clazz.getName() + POSTFIX_SELECTBYIDS, ids);
[*] }
[*]
[*] /**
[*] * 直接从数据库查询出ids列表（包括符合条件的所有id）
[*] *
[*] * @param properties
[*] * 查询条件字段名
[*] * @param propertyValues
[*] * 字段取值
[*] * @return
[*] */
[*] public List<PK> findIdsBy(String[] properties, Object[] propertyValues, String orderBy, String order) {
[*] Map<String, Object> map = new HashMap<String, Object>();
[*] for (int i = 0; i < properties.length; i++) {
[*] map.put(properties, propertyValues);
[*] }
[*] if (orderBy != null) {
[*] map.put("orderBy", orderBy);
[*] map.put("order", order);
[*] }
[*] return (List<PK>) slaveSqlMapClientTemplate.queryForList(clazz.getName() + POSTFIX_PKSELECTMAP, map);
[*] }
[*]
[*] /**
[*] * 根据条件查询结果
[*] *
[*] * @param properties
[*] * 查询条件名
[*] * @param propertyValues
[*] * 查询条件值
[*] * @return
[*] */
[*] public List<T> findByMap(String[] properties, Object[] propertyValues, String orderBy, String order) {
[*] return (List<T>) slaveSqlMapClientTemplate.queryForList(clazz.getName() + POSTFIX_SELECTBYMAP, map);
[*] }
[*]
[*] /**
[*] * 根据条件查询结果的id列表
[*] *
[*] * @param properties
[*] * 查询条件名
[*] * @param propertyValues
[*] * 查询条件值
[*] * @return
[*] */
[*] public List<PK> findIdsByMap(String[] properties, Object[] propertyValues, String orderBy, String order) {
[*] Map<String, Object> map = new HashMap<String, Object>();
[*] for (int i = 0; i < properties.length; i++) {
[*] map.put(properties, propertyValues);
[*] }
[*] if (orderBy != null) {
[*] map.put("orderBy", orderBy);
[*] map.put("order", order);
[*] }
[*] return (List<PK>) slaveSqlMapClientTemplate.queryForList(clazz.getName() + POSTFIX_PKSELECTMAP, map);
[*] }
[*]
[*] /**
[*] * 分页查询（未处理缓存）
[*] *
[*] * @param properties
[*] * 查询条件字段名
[*] * @param propertyValues
[*] * 字段取值
[*] * @return
[*] */
[*] public List<T> pageQueryBy(String[] properties, Object[] propertyValues, String orderBy, String order, int pageSize, int pageNo) {
[*] Map<String, Object> map = new HashMap<String, Object>();
[*] for (int i = 0; i < properties.length; i++) {
[*] map.put(properties, propertyValues);
[*] }
[*] if (orderBy != null) {
[*] map.put("orderBy", orderBy);
[*] map.put("order", order);
[*] }
[*] map.put("limit", true);
[*] map.put("start", (pageNo - 1) * pageSize );// limit 操作
[*] map.put("end", pageSize);
[*] return (List<T>) slaveSqlMapClientTemplate.queryForList(clazz.getName() + POSTFIX_SELECTBYMAP, map);
[*] }
[*]
[*] /**
[*] * 从数据库分页查询出ids列表的前200个id
[*] *
[*] * @param properties
[*] * 查询条件字段名
[*] * @param propertyValues
[*] * 字段取值
[*] * @return
[*] */
[*] protected List<PK> pageQueryIdsBy(String[] properties, Object[] propertyValues, String orderBy, String order) {
[*] Map<String, Object> map = new HashMap<String, Object>();
[*] for (int i = 0; i < properties.length; i++) {
[*] map.put(properties, propertyValues);
[*] }
[*] if (orderBy != null) {
[*] map.put("orderBy", orderBy);
[*] map.put("order", order);
[*] }
[*] map.put("limit", true);
[*] map.put("start", 0);// 操作
[*] map.put("end", Config.getInstance().getPageCacheSize());
[*] return (List<PK>) slaveSqlMapClientTemplate.queryForList(clazz.getName() + POSTFIX_PKSELECTMAP, map);
[*]
[*] }
[*]
[*] /**
[*] * 分页查询出id列表（处理缓存）
[*] *
[*] * @param properties
[*] * 查询条件字段名
[*] * @param propertyValues
[*] * 字段取值
[*] * @return
[*] */
[*] public List<PK> pageQueryIdsByMap(String[] properties, Object[] propertyValues, String orderBy, String order, int pageSize, int pageNo) {
[*] Map<String, Object> map = new HashMap<String, Object>();
[*] for (int i = 0; i < properties.length; i++) {
[*] map.put(properties, propertyValues);
[*] }
[*] if (orderBy != null) {
[*] map.put("orderBy", orderBy);
[*] map.put("order", order);
[*] }
[*] map.put("limit", true);
[*] map.put("start", (pageNo - 1) * pageSize );// limit 操作
[*] map.put("end", pageSize);
[*] return (List<PK>) slaveSqlMapClientTemplate.queryForList(clazz.getName() + POSTFIX_PKSELECTMAP, map);
[*] }
[*]
[*] /** like分页查询(不走列表缓存) */
[*] public List<T> pageLikeBy(String[] properties, Object[] propertyValues, String orderBy, String order, int pageSize, int pageNo){
[*] Map<String, Object> map = new HashMap<String, Object>();
[*] for (int i = 0; i < properties.length; i++) {
[*] map.put(properties, propertyValues);
[*] }
[*] if (orderBy != null) {
[*] map.put("orderBy", orderBy);
[*] map.put("order", order);
[*] }
[*] map.put("limit", true);
[*] map.put("start", (pageNo - 1) * pageSize );// limit 操作
[*] map.put("end", pageSize);
[*] List<PK> ids = (List<PK>) slaveSqlMapClientTemplate.queryForList(clazz.getName() + POSTFIX_SELECTIDSLIKEBYMAP, map);
[*] return findByIds(ids);
[*] }
[*]
[*] /**
[*] * 新增对象
[*] */
[*] public Serializable insert(T o) throws Exception {
[*] if (t instanceof QueryCachable) {
[*] // 清除受影响的缓存
[*] clearListCache(o);
[*] }
[*] return (Serializable) masterSqlMapClientTemplate.insert(clazz.getName() + POSTFIX_INSERT, o);
[*] }
[*]
[*]
[*] /**
[*] * 更新对象
[*] */
[*] public T update(T o) throws Exception {
[*] masterSqlMapClientTemplate.update(clazz.getName() + POSTFIX_UPDATE, o);
[*] return o;
[*] }
[*]
[*] /**
[*] * 更新对象的部分属性
[*] */
[*] public int update(PK id, String[] properties, Object[] propertyValues) throws Exception {
[*] // 更新数据库
[*] Map<String, Object> map = new HashMap<String, Object>();
[*] for (int i = 0; i < properties.length; i++) {
[*] map.put(properties, propertyValues);
[*] }
[*] map.put("id", id);
[*] return masterSqlMapClientTemplate.update(clazz.getName() + POSTFIX_UPDATEBYMAP, map);
[*] }
[*]
[*] /**
[*] * 根据ID列表更新对象的部分属性
[*] */
[*] public int updateByIdsMap(List<PK> ids,String[] properties, Object[] propertyValues) throws Exception{
[*] // 更新数据库
[*] Map<String, Object> map = new HashMap<String, Object>();
[*] for (int i = 0; i < properties.length; i++) {
[*] map.put(properties, propertyValues);
[*] }
[*] map.put("ids", ids);
[*] return masterSqlMapClientTemplate.update(clazz.getName() + POSTFIX_UPDATEBYIDSMAP, map);
[*] }
[*]
[*] /**
[*] * 根据ID删除对象
[*] */
[*] public void deleteById(PK id) throws Exception {
[*] masterSqlMapClientTemplate.delete(clazz.getName() + POSTFIX_DELETEBYID, id);
[*] }
[*]
[*] /**
[*] * 根据ID删除对象
[*] */
[*] public void deleteByIds(List<PK> ids) throws Exception {
[*] masterSqlMapClientTemplate.delete(clazz.getName() + POSTFIX_DELETEBYIDS, ids);
[*] }
[*]
[*] /** 根据ID及条件删除对象 */
[*] public void deleteByIdsMap(List<PK> ids, String[] properties, Object[] propertyValues) throws Exception {
[*] Map<String, Object> map = new HashMap<String, Object>();
[*] for (int i = 0; i < properties.length; i++) {
[*] map.put(properties, propertyValues);
[*] }
[*] map.put("ids", ids);
[*] masterSqlMapClientTemplate.delete(clazz.getName() + POSTFIX_DELETEBYIDSMAP, map);
[*] }
[*]
[*] /**
[*] * 根据条件删除对象
[*] */
[*] public int deleteByMap(String[] properties, Object[] propertyValues) throws Exception {
[*]
[*] Map<String, Object> map = new HashMap<String, Object>();
[*] for (int i = 0; i < properties.length; i++) {
[*] map.put(properties, propertyValues);
[*] }
[*] return masterSqlMapClientTemplate.delete(clazz.getName() + POSTFIX_DELETEBYMAP, map);
[*] }
[*]
[*] /**
[*] * 根据自定义SqlMap中的条件语句查询出列表(注意：不处理缓存)
[*] */
[*] public List<T> findByStatementPostfix(String statementPostfix, String[] properties, Object[] propertyValues, String orderBy, String order) {
[*] Map<String, Object> map = new HashMap<String, Object>();
[*] for (int i = 0; i < properties.length; i++) {
[*] map.put(properties, propertyValues);
[*] }
[*] if (orderBy != null) {
[*] map.put("orderBy", orderBy);
[*] map.put("order", order);
[*] }
[*] return slaveSqlMapClientTemplate.queryForList(clazz.getName() + statementPostfix, map);
[*] }
[*]
[*] /**
[*] * 根据自定义SqlMap中的条件语句查询出列表(注意：不处理缓存)
[*] */
[*] public List<T> pageQueryByStatementPostfix(String statementPostfix, String[] properties, Object[] propertyValues, String orderBy, String order,int pageSize,int pageNo) {
[*] Map<String, Object> map = new HashMap<String, Object>();
[*] for (int i = 0; i < properties.length; i++) {
[*] map.put(properties, propertyValues);
[*] }
[*] if (orderBy != null) {
[*] map.put("orderBy", orderBy);
[*] map.put("order", order);
[*] }
[*] map.put("limit", true);
[*] map.put("start", (pageNo - 1) * pageSize );// limit 操作
[*] map.put("end", pageSize);
[*] List<PK> ids = (List<PK>) slaveSqlMapClientTemplate.queryForList(clazz.getName() + statementPostfix, map);
[*] return findByIds(ids);
[*] }
[*]
[*] /**
[*] * 根据自定义SqlMap中的条件语句更新数据（注意：不处理缓存）
[*] */
[*] public void updateByStatementPostfix(String statementPostfix, String[] properties, Object[] propertyValues) {
[*] Map<String, Object> map = new HashMap<String, Object>();
[*] for (int i = 0; i < properties.length; i++) {
[*] map.put(properties, propertyValues);
[*] }
[*] masterSqlMapClientTemplate.update(clazz.getName() + statementPostfix, map);
[*] }
[*]
[*] /**
[*] * 根据自定义SqlMap中的条件语句删除数据（注意：不处理缓存）
[*] */
[*] public void deleteByStatementPostfix(String statementPostfix, String[] properties, Object[] propertyValues) {
[*] Map<String, Object> map = new HashMap<String, Object>();
[*] for (int i = 0; i < properties.length; i++) {
[*] map.put(properties, propertyValues);
[*] }
[*] masterSqlMapClientTemplate.delete(clazz.getName() + statementPostfix, map);
[*] }
[*]
[*] /**
[*] * 根据自定义SqlMap中的条件语句插入数据（注意：不处理缓存）
[*] */
[*] public void insertByStatementPostfix(String statementPostfix, String[] properties, Object[] propertyValues) {
[*] Map<String, Object> map = new HashMap<String, Object>();
[*] for (int i = 0; i < properties.length; i++) {
[*] map.put(properties, propertyValues);
[*] }
[*] masterSqlMapClientTemplate.insert(clazz.getName() + statementPostfix, map);
[*] }
[*]
[*]}
3、所有其他Dao只需继承GenericDao，不需再写增删改查的方法
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[*]package com.teacherclub.business.album.dao;
[*]
[*]import org.springframework.stereotype.Repository;
[*]
[*]import com.teacherclub.business.album.entity.Album;
[*]import com.teacherclub.core.mem.MemcacheUtil;
[*]import com.teacherclub.core.orm.EntityCachable;
[*]import com.teacherclub.core.orm.dao.impl.GenericDao;
[*]
[*]@Repository
[*]public class AlbumDao extends GenericDao<Album,Integer> {
[*]
[*]}
此泛型的实现，关键在于：clazz = (Class<T>) ((ParameterizedType) getClass().getGenericSuperclass()).getActualTypeArguments();
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