JavaEE 3层架构的的 DAO, Service, Web 简单封装

由于大多数项目都是使用开源的 SSH 三大框架来做. 所以对DAO, Service 层进行了简单的封装. 封装的方法非常简单, 就是将 Hibernate 的 CURD 等常用方法封装起来. 免得每一个 DAO 内都需要再写这些方法. Service 相同.

实现的逻辑大体是

GeneralDAO(Interface). AbstractGeneralDAOImpl(Abstract class),  GeneralService(Interface), AbstractGeneralServiceImpl(Abstract class).

具体

IDAO extends GeneralDAO, 

IDAOImpl extends AbstractGeneralDAOImpl,

IService extends GeneralService,

IServiceImpl extends AbstractGeneralServiceImpl

 

实现代码如下.

GeneralDAO<T, ID extends Serializable>

import java.io.Serializable;
import java.util.Collection;
import java.util.List;

import PagingVO;

/**
 * General DAO
 *
 * @author Hacker-TTAO
 * @version 0.1.0
 */
public interface GeneralDAO<T, ID extends Serializable> {

    T findByID(ID id);

    List<T> findAll();

    PagingVO getPagingData(int currentPage, int pageSize);

    T save(T entity);

    void save(T... entity);

    T update(T entity);

    void update(Collection<T> entity);

    void saveOrUpdate(T entity);

    void saveOrUpdate(Collection<T> entities);

    void delete(T entity);

    void delete(ID id);

    void delete(Collection<T> entities);

    void marge(T eneity);

    void marge(T... eneity);

    int getCount();
}

 

AbstractGeneralDAOImpl<T, ID extends Serializable>

import java.io.Serializable;
import java.lang.reflect.ParameterizedType;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

/**
 * Abstract General DAO Implement
 *
 * @author Hacker-TTAO
 * @version 0.1.0
 */
public abstract class AbstractGeneralDAOImpl<T, ID extends Serializable> implements GeneralDAO<T, ID> {

    private final Log log = LogFactory.getLog(this.getClass());

    protected final Class<T> persistenceClass;

    protected final Class<T> pkClass;

    protected AbstractGeneralDAOImpl() {
        this.persistenceClass = (Class<T>) ((ParameterizedType) getClass().getGenericSuperclass()).getActualTypeArguments()[0];
        this.pkClass = (Class<T>) ((ParameterizedType) getClass().getGenericSuperclass()).getActualTypeArguments()[1];

        if (log.isInfoEnabled()) {
            log.info("解析泛型参数 T : " + getPersistenceClass().getName());
        }
    }

    protected final Class<T> getPersistenceClass() {
        return persistenceClass;
    }

    protected Class<T> getPkClass() {
        return pkClass;
    }
}

 

基于 Spring 封装的 Hibernate DAO 抽象实现

AbstractSpringDAO<T, ID extends Serializable>

import java.io.Serializable;
import java.sql.SQLException;
import java.util.Collection;
import java.util.List;

import org.hibernate.Criteria;
import org.hibernate.HibernateException;
import org.hibernate.Session;
import org.hibernate.criterion.Projections;
import org.springframework.orm.hibernate3.HibernateCallback;
import org.springframework.orm.hibernate3.HibernateTemplate;

/**
 * 基于 Spring Hibernate 的DAO
 *
 * @author Hacker-TTAO
 *
 * @param <T>
 * @param <ID>
 */
public abstract class AbstractSpringDAO<T, ID extends Serializable> extends AbstractGeneralDAOImpl<T, ID> {

    private HibernateTemplate hibernateTemplate;

    public HibernateTemplate getHibernateTemplate() {
        return hibernateTemplate;
    }

    public void setHibernateTemplate(HibernateTemplate hibernateTemplate) {
        this.hibernateTemplate = hibernateTemplate;
    }

    public List<T> findAll() {
        return getHibernateTemplate().loadAll(getPersistenceClass());
    }

    public T findByID(ID id) {
        return (T) getHibernateTemplate().get(getPersistenceClass(), id);
    }

    public void delete(T entity) {
        getHibernateTemplate().delete(entity);
    }

    public void delete(Collection<T> entities) {
        getHibernateTemplate().deleteAll(entities);
    }

    public void marge(T eneity) {
        getHibernateTemplate().merge(eneity);
    }

    public void marge(T... eneity) {
    }

    public T save(T entity) {
        getHibernateTemplate().save(entity);
        return entity;
    }

    public void save(T... entity) {
    }

    public void saveOrUpdate(T entity) {
        getHibernateTemplate().saveOrUpdate(entity);
    }

    public void saveOrUpdate(Collection<T> entities) {
        getHibernateTemplate().saveOrUpdate(entities);
    }

    public T update(T entity) {
        getHibernateTemplate().update(entity);
        return entity;
    }

    public void update(Collection<T> entity) {
    }

    public int getCount() {
        Object obj = getHibernateTemplate().execute(new HibernateCallback() {
            public Object doInHibernate(Session session) throws HibernateException, SQLException {
                Criteria c = session.createCriteria(getPersistenceClass());
                c.setProjection(Projections.rowCount());
                return c.uniqueResult();
            }
        });
        return Integer.parseInt(obj.toString());
    }

    public void delete(ID id) {
        T entity = findByID(id);
        delete(entity);
    }
}

具体 DAO 实现.

XtyhbDAO

import Xtyhb;

/**
 * @author Hacker-TTAO
 * @version 1.0
 * Create Date : Nov 11, 2009 1:34:16 PM
 * Change List:
 */
public interface XtyhbDAO extends GeneralDAO<Xtyhb, Integer>  {
    Xtyhb findByNameAndPwd(String username, String password);
}

 

XtyhbDAOImpl

import java.util.List;

/**
 *
 * @author Hacker-TTAO
 * @version 0.0.1
 * Create Date : Nov 11, 2009 1:35:10 PM
 * Change List:
 */
@SuppressWarnings("unchecked")
public class XtyhbDAOImpl extends AbstractSpringDAO<Xtyhb, Integer> implements XtyhbDAO {

    public Xtyhb findByNameAndPwd(String username, String password) {
        // implement
        return null;
    }

    public PagingVO getPagingData(int currentPage, int pageSize) {
        return null;
    }
}

 

至此. DAO 层封装完毕. 下面进行 Service 层封装

GeneralService<T, ID extends Serializable, DAO extends GeneralDAO<T, ID>>

import java.io.Serializable;
import java.util.Collection;
import java.util.List;

/**
 *
 * @author Hacker-TTAO
 *
 * @param <T>
 * @param <ID>
 * @param <DAO>
 */
public interface GeneralService<T, ID extends Serializable, DAO extends GeneralDAO<T, ID>> {
    T findByID(ID id);

    List<T> findAll();

    T save(T entity);

    void save(T... entity);

    T update(T entity);

    void update(Collection<T> entity);

    void saveOrUpdate(T entity);

    void saveOrUpdate(Collection<T> entities);

    void delete(T entity);

    void delete(Collection<T> entities);

    void delete(ID id);

    void marge(T eneity);

    void marge(T... eneity);
}

 

AbstractServiceImpl<T, ID extends Serializable, DAO extends GeneralDAO<T, ID>>

import java.io.Serializable;
import java.util.Collection;
import java.util.List;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

/**
 *
 * @author Hacker-TTAO
 *
 * @param <T>
 * @param <ID>
 * @param <DAO>
 */
public abstract class AbstractServiceImpl<T, ID extends Serializable, DAO extends GeneralDAO<T, ID>> implements GeneralService<T, ID, DAO> {

    private DAO dao;

    private static final Log log = LogFactory.getLog(AbstractServiceImpl.class);

    public List<T> findAll() {
        List<T> result = getDao().findAll();
        log.info("findAll execute success");
        return result;
    }

    public T findByID(ID id) {
        T result = getDao().findByID(id);
        log.info("findById execute success");
        return result;
    }

    public void delete(Collection<T> entities) {
        getDao().update(entities);
    }

    public void delete(T entity) {
        getDao().delete(entity);
    }

    public void delete(ID id) {
        getDao().delete(id);
    }

    public void marge(T... eneity) {
    }

    public void marge(T eneity) {
        getDao().marge(eneity);

    }

    public void save(T... entity) {
        getDao().save(entity);
    }

    public T save(T entity) {
        return getDao().save(entity);
    }

    public void saveOrUpdate(Collection<T> entities) {
        getDao().saveOrUpdate(entities);
    }

    public void saveOrUpdate(T entity) {
        getDao().saveOrUpdate(entity);
    }

    public void update(Collection<T> entity) {
        getDao().update(entity);
    }

    public T update(T entity) {
        return getDao().update(entity);
    }

    public DAO getDao() {
        return dao;
    }

    public void setDao(DAO dao) {
        this.dao = dao;
    }

}

 

XtyhbSerivce

/**
 *
 * @author Hacker-TTAO
 * @version 0.0.1
 * Create Date : Nov 11, 2009 1:36:20 PM
 * Change List:
 */
public interface XtyhbService extends GeneralService<Xtyhb, Integer, XtyhbDAO> {
    Xtyhb findByNameAndPwd(Xtyhb xtyhb);
}

 

 

XtyhbServiceImpl

/**
 *
 * @author Hacker-TTAO
 * @version 1.0
 * Create Date : Nov 11, 2009 1:36:54 PM
 * Change List:
 */
public class XtyhbServiceImpl extends AbstractServiceImpl<Xtyhb, Integer, XtyhbDAO> implements XtyhbService {

    public Xtyhb findByNameAndPwd(Xtyhb xtyhb) {
        return getDao().findByNameAndPwd(xtyhb.getYhmc(), xtyhb.getMm());
    }
}

 

Service 层封装完毕. Web 层调用 Service

public class LoginAction {
    /*----------------- ACTION RESULT CONSTANT FILED -------------------------*/
    public static final String FAILURE = "failure";

    /*---------------------- Page | Action Parameters ------------------------*/
    private Xtyhb xtyhb;
    private String message;

    /*--------------------- Service Refrence Object --------------------------*/
    private XtyhbService xtyhbService;

    /*------------------------ GETTER AND SETTER  ----------------------------*/

    public String getMessage() {
        return message;
    }

    public void setMessage(String message) {
        this.message = message;
    }

    public Xtyhb getXtyhb() {
        return xtyhb;
    }

    public void setXtyhb(Xtyhb xtyhb) {
        this.xtyhb = xtyhb;
    }

    public XtyhbService getXtyhbService() {
        return xtyhbService;
    }

    public void setXtyhbService(XtyhbService xtyhbService) {
        this.xtyhbService = xtyhbService;
    }

    public String login() {
        xtyhb.setMm(MD5Encrypt.getMD5(xtyhb.getMm()));
        Xtyhb loginUser = getXtyhbService().findByNameAndPwd(xtyhb);

        if (null == loginUser) {
            message = "没有此用户";
            return FAILURE;
        }

        if (XtyhbStateConst.DISABLE == loginUser.getYhzt()) {
            message = "此用户被禁用";
            return FAILURE;
        }

        // if user is admin
        if (ADMIN_USER.equals(loginUser.getYhmc())) {
            ActionContextUtil.setAttr2Session("menuTree", ADMIN_FUNCTION);
        } else {
            List<Xtflb> xtflbs = getXtflbService().findByXtyhb(loginUser);
            ActionContextUtil.setAttr2Session("xtflbs", xtflbs);
            ActionContextUtil.setAttr2Session("menuTree", CreateMenuTreeUtil.createMenuTree(xtflbs));
        }

        ActionContextUtil.setAttr2Session("user", loginUser);
        return Action.SUCCESS;
    }
}

 

至此. 简单的封装结束.  在 Web 层 Action 中调用类似 CURD 的方法时, 每个 DAO 和 Service 就不需要写了.