巴巴运动网学习笔记(16-20)

1.ProductType的JPA映射

@Entity
public class ProductType {
    private int id;
    private String name;
    private String note;
    private boolean visible = true;
    private Set<ProductType> child;
    private ProductType parent;

    @Id @GeneratedValue(strategy = GenerationType.AUTO)
    public int getId() {
        return id;
    }

    public void setId(int id) {
        this.id = id;
    }
    @Column(length=30,nullable=false)
    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }
    @Column(length=100)
    public String getNote() {
        return note;
    }

    public void setNote(String note) {
        this.note = note;
    }
    @Column(nullable=false)
    public boolean isVisible() {
        return visible;
    }

    public void setVisible(boolean visible) {
        this.visible = visible;
    }
    @OneToMany(cascade={CascadeType.REFRESH,CascadeType.REMOVE},mappedBy="parent")
    public Set<ProductType> getChild() {
        return child;
    }

    public void setChild(Set<ProductType> child) {
        this.child = child;
    }
    @ManyToOne(cascade=CascadeType.REFRESH) @JoinColumn(name="parentid")
    public ProductType getParent() {
        return parent;
    }

    public void setParent(ProductType parent) {
        this.parent = parent;
    }
    
}

2.实现ProductType的无限级分类

@OneToMany(cascade={CascadeType.REFRESH,CascadeType.REMOVE},mappedBy="parent")
    public Set<ProductType> getChild() {
        return child;
    }

    public void setChild(Set<ProductType> child) {
        this.child = child;
    }
    @ManyToOne(cascade=CascadeType.REFRESH) @JoinColumn(name="parentid")
    public ProductType getParent() {
        return parent;
    }

    public void setParent(ProductType parent) {
        this.parent = parent;
    }

3.实现ProductTypeService和ProductTypeServiceImpl

a.创建DAO接口,实现增删改查代码的服用

package cnblogs.xiaoqiu.service.base;

public interface DAO {
    
    /**
     * 保存实体
     * @param entity
*/
    public void save(Object entity);
    /**
     * 删除实体
     * @param entity
*/
    public <T> void delete(Class<T> classType,Object entityId);
    /**
     * 
     * @param entitys 要删除的实体的ID数组
*/
    public <T> void delete(Class<T> classType,Object[] entitysId);
    /**
     * 更新实体
     * @param entity
*/
    public void update(Object entity);
    /**
     * 查找实体
     * @param <T>
     * @param classType 实体的类型
     * @param id 实体的ID
     * @return
*/
    public <T> T find(Class<T> classType,Object id);
}

b.创建DAOSupport抽象类,为以后类实现DAO接口提供方便

package cnblogs.xiaoqiu.service.base;

import javax.persistence.EntityManager;
import javax.persistence.PersistenceContext;

import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Propagation;
import org.springframework.transaction.annotation.Transactional;

@Service @Transactional
public abstract class DAOSupport implements DAO {
    @PersistenceContext protected EntityManager entityManager;
    
    public <T> void delete(Class<T> classType,Object entityId) {
        entityManager.remove(entityManager.getReference(classType, entityId));

    }

    public <T> void delete(Class<T> classType,Object[] entitysId) {
        for(int i=0;i<entitysId.length;i++){
            delete(classType, entitysId[i]);
        }
    }
    @Transactional(readOnly=true,propagation=Propagation.NOT_SUPPORTED)
    public <T> T find(Class<T> classType, Object id) {
        return entityManager.find(classType, id);
    }

    public void save(Object entity) {
        entityManager.persist(entity);
    }

    public void update(Object entity) {
        entityManager.merge(entity);
    }

}

c.创建ProductTypeService接口

package cnblogs.xiaoqiu.service.product;

import cnblogs.xiaoqiu.service.base.DAO;

public interface ProductTypeService extends DAO{

}

d.创建ProductTypeServiceImpl类

package cnblogs.xiaoqiu.service.product.impl;

import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;
import cnblogs.xiaoqiu.service.base.DAOSupport;
import cnblogs.xiaoqiu.service.product.ProductTypeService;

@Service @Transactional
public class ProductTypeServiceImpl extends DAOSupport implements ProductTypeService {    
}

4.覆盖DAOSupport的delete方法

package cnblogs.xiaoqiu.service.product.impl;

import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;
import cnblogs.xiaoqiu.service.base.DAOSupport;
import cnblogs.xiaoqiu.service.product.ProductTypeService;

@Service @Transactional
public class ProductTypeServiceImpl extends DAOSupport implements ProductTypeService {

    @Override
    public <T> void delete(Class<T> classType, Object entityId) {
        String jpql = "update ProductType p set p.visible=?1";
        entityManager.createQuery(jpql).setParameter(1, false).executeUpdate();
    }
    
}

5.测试ProductTypeServiceImpl