---

DAO架构的小总结

整理一下在悠悠校园中的DAO层的设计思路。

项目的目录的结构

项目的目录结构
1440938319880.png
1440938340860.png

首先是BaseDao

    public interface BaseDao<T> {
    
        T get(Class<T> entityClazz, Serializable id);
    
        Serializable save(T entity);
    
        void update(T entity);
    
        void delete(T entity);
    
        void delete(Class<T> entityClazz, Serializable id);
    
        List<T> findAll(Class<T> entityClazz);
    }

接着是BaseDaoImpl,这里采用的是hibernate作为数据库访问的方法

    package com.yoyo.dao.impl;
    import java.io.Serializable;
    import java.util.List;
    import org.hibernate.Query;
    import org.hibernate.SessionFactory;
    import com.yoyo.cons.CommonConstant;
    import com.yoyo.dao.inter.BaseDao;
    public class BaseDaoImpl<T> implements BaseDao<T> {
        private SessionFactory sessionFactory;
        public void setSessionFactory(SessionFactory sessionFactory) {
            this.sessionFactory = sessionFactory;
        }
        
        public SessionFactory getSessionFactory() {
            return this.sessionFactory;
        }
        
        @SuppressWarnings("unchecked")
        public T get(Class<T> entityClazz, Serializable id) {
            return (T) getSessionFactory().getCurrentSession().get(entityClazz, id);
        }
        
        public Serializable save(T entity) {
            return getSessionFactory().getCurrentSession().save(entity);
        }
        
        public void update(T entity) {
            getSessionFactory().getCurrentSession().saveOrUpdate(entity);
        }
        
        public void delete(T entity) {
            getSessionFactory().getCurrentSession().delete(entity);
        }
        
        public void delete(Class<T> entityClazz, Serializable id) {
            delete(get(entityClazz, id));
        }
    
        public List<T> findAll(Class<T> entityClazz) {
            return find("from " + entityClazz.getSimpleName());
        }
    
        @SuppressWarnings("unchecked")
        protected List<T> find(String hql) {
            return (List<T>) getSessionFactory().getCurrentSession()
                    .createQuery(hql).list();
        }
    
        @SuppressWarnings("unchecked")
        protected List<T> find(String hql, Object... params) {
            Query query = getSessionFactory().getCurrentSession().createQuery(hql);
            for (int i = 0, len = params.length; i < len; i++) {
                query.setParameter(i + "", params[i]);
            }
            return (List<T>) query.list();
        }
        
        protected List<T> findByPage(String hql, int pageNo,Object... params){
            Query query = getSessionFactory().getCurrentSession().createQuery(hql);
            for (int i = 0, len = params.length; i < len; i++) {
                query.setParameter(i + "", params[i]);
            }
            int pageSize = new CommonConstant().PAGE_SIZE;
            query.setFirstResult(pageNo * pageSize);
            query.setMaxResults(pageSize);
            return (List<T>) query.list();
        }
    }

BaseDomain的设计

    package com.yoyo.domain;
    import java.io.Serializable;
    import org.apache.commons.lang.builder.ToStringBuilder;
    public class BaseDomain implements Serializable{
        public String toString(){
            return ToStringBuilder.reflectionToString(this);
        }
    }

下面以MainUser作为案例给出相应的实现类

MainUserDao

    package com.yoyo.dao.inter;

    import java.util.List;
    import java.util.Set;
    
    import com.yoyo.domain.Comment;
    import com.yoyo.domain.MainUser;
    
    public interface MainUserDao {
        public List<MainUser> findAll();
        public MainUser getMainUserById(int i);
        public MainUser getMainUserByName(String name);
        public void UpdateMainUser(MainUser mainUser);
        public void DeleteMainUser(MainUser mainUser);
        public void AddMainUser(MainUser mainUser);
        public Set<Comment> getAllComments(MainUser mainUser);
    }
MainUserDaoImpl

    package com.yoyo.dao.impl;

    import java.util.List;
    import java.util.Set;
    
    import com.yoyo.dao.inter.MainUserDao;
    import com.yoyo.domain.Comment;
    import com.yoyo.domain.MainUser;
    
    public class MainUserDaoImpl extends BaseDaoImpl<MainUser> implements MainUserDao{
        private final String GET_MAINUSER_BY_ID = "from MainUser u where u.uid = ?0";
        private final String GET_MAINUSER_BY_NAME = "from MainUser u where u.username = ?0";
        public List<MainUser> findAll(){
            List<MainUser> list = find("from MainUser");
            if(list.size() == 0)
                System.out.println("Emptuy List");
            return list;
        }
        public MainUser getMainUserById(int i){
            List<MainUser> list = find(GET_MAINUSER_BY_ID, i);
            if(list.isEmpty()){
                System.out.println("isEmpty");
            }
            return list.get(0);
        }
        
        public MainUser getMainUserByName(String name){
            List<MainUser> list = find(GET_MAINUSER_BY_NAME, name);
            if(list.isEmpty()){
                System.out.println("IsEmpty");
            }
            return list.get(0);
        }
        
        public void UpdateMainUser(MainUser mainUser){
            update(mainUser);
        }
        public void DeleteMainUser(MainUser mainUser){
            delete(mainUser);
        }
        
        public void AddMainUser(MainUser mainUser){
            save(mainUser);
        }
        
        public Set<Comment> getAllComments(MainUser mainUser){
            Set<Comment> list = mainUser.getCommentList();
            return list;
        }
    }

MainUser

    package com.yoyo.domain;

    import java.util.Date;
    import java.util.HashSet;
    import java.util.List;
    import java.util.Set;
    
    import javax.persistence.CascadeType;
    import javax.persistence.Column;
    import javax.persistence.Entity;
    import javax.persistence.FetchType;
    import javax.persistence.GeneratedValue;
    import javax.persistence.Id;
    import javax.persistence.ManyToMany;
    import javax.persistence.OneToMany;
    import javax.persistence.OrderBy;
    import javax.persistence.Table;
    
    import com.sun.org.apache.bcel.internal.generic.NEW;
    
    
    @Entity
    @Table(name="tao_mainusers")
    public class MainUser extends BaseDomain{
        private int uid;
        private String userimage;
        private String username;
        private String qq;
        private String phoneNum;
        private String phonePublic;
        private int score;
        private String sign;
        private int sex;
        private String home_city;
        private String home_province;
        private Date birthday;
        private String school;
        private int schoolTime;
        private int collectionPublic;
        private Date signinDate;
        private String homeArea;
        private Set<Comment> commentList;
        private Set<LotteryResult> lotteryResults;
    
        @Id
        @GeneratedValue
        public int getUid() {
            return uid;
        }
        public void setUid(int uid) {
            this.uid = uid;
        }
        public String getUserimage() {
            return userimage;
        }
        public void setUserimage(String userimage) {
            this.userimage = userimage;
        }
        public String getUsername() {
            return username;
        }
        public void setUsername(String username) {
            this.username = username;
        }
        public String getQq() {
            return qq;
        }
        public void setQq(String qq) {
            this.qq = qq;
        }
        
        @Column(name="phonenum")
        public String getPhoneNum() {
            return phoneNum;
        }
        public void setPhoneNum(String phoneNum) {
            this.phoneNum = phoneNum;
        }
        
        @Column(name="phonepublic")
        public String getPhonePublic() {
            return phonePublic;
        }
        public void setPhonePublic(String phonePublic) {
            this.phonePublic = phonePublic;
        }
        public int getScore() {
            return score;
        }
        public void setScore(int score) {
            this.score = score;
        }
        public String getSign() {
            return sign;
        }
        public void setSign(String sign) {
            this.sign = sign;
        }
        public int getSex() {
            return sex;
        }
        public void setSex(int sex) {
            this.sex = sex;
        }
        public String getHome_city() {
            return home_city;
        }
        public void setHome_city(String home_city) {
            this.home_city = home_city;
        }
        public String getHome_province() {
            return home_province;
        }
        public void setHome_province(String home_province) {
            this.home_province = home_province;
        }
        public Date getBirthday() {
            return birthday;
        }
        public void setBirthday(Date birthday) {
            this.birthday = birthday;
        }
        public String getSchool() {
            return school;
        }
        public void setSchool(String school) {
            this.school = school;
        }
        
        @Column(name = "schooltime")
        public int getSchoolTime() {
            return schoolTime;
        }
        public void setSchoolTime(int schoolTime) {
            this.schoolTime = schoolTime;
        }
        
        @Column(name = "collectionpublic")
        public int getCollectionPublic() {
            return collectionPublic;
        }
        public void setCollectionPublic(int collectionPublic) {
            this.collectionPublic = collectionPublic;
        }
        @Column(name = "signin_date")
        public Date getSigninDate() {
            return signinDate;
        }
        public void setSigninDate(Date signinDate) {
            this.signinDate = signinDate;
        }
        @Column(name = "home_area")
        public String getHomeArea() {
            return homeArea;
        }
        public void setHomeArea(String homeArea) {
            this.homeArea = homeArea;
        }
        
        @OneToMany(mappedBy = "mainUser",targetEntity=Comment.class, cascade = CascadeType.ALL, fetch=FetchType.EAGER)
        public Set<Comment> getCommentList() {
            return commentList;
        }
        public void setCommentList(Set<Comment> commentList) {
            this.commentList = commentList;
        }
        
        @OneToMany(mappedBy="mainUser",targetEntity=LotteryResult.class,cascade = CascadeType.ALL,fetch=FetchType.EAGER)
        public Set<LotteryResult> getLotteryResults(){
            return lotteryResults;
        }
        
        public void setLotteryResults(Set<LotteryResult> lotteryResults){
            this.lotteryResults = lotteryResults;
        }
    }

---

引用和版权说明

欢迎大家分享、转发。在联系原作者并标明出处及原链接，保留作者署名，非商业应用，相同方式共享，本文欢迎转载。非经授权许可，禁止转载。本文采用 CC BY-NC-SA 4.0授权。