genericdao.java

来自「对XML和DB的CURD的基本操作.使用的两个比较常用的组合设计模式：MVC模式」· Java 代码 · 共 55 行

package com.mycompany.myapp.dao;

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


/**
 * Generic DAO (Data Access Object) with common methods to CRUD POJOs.
 *
 * <p>Extend this interface if you want typesafe (no casting necessary) DAO's for your
 * domain objects.
 *
 * @param <T> a type variable
 * @param <PK> the primary key for that type
 */
public interface GenericDao <T, PK extends Serializable> {

    /**
     * Generic method used to get all objects of a particular type. This
     * is the same as lookup up all rows in a table.
     * @return List of populated objects
     */
    List<T> getAll();
    
    /**
     * Generic method to get an object based on class and identifier. An
     * ObjectRetrievalFailureException Runtime Exception is thrown if
     * nothing is found.
     *
     * @param id the identifier (primary key) of the object to get
     * @return a populated object
     * @see org.springframework.orm.ObjectRetrievalFailureException
     */
    T get(PK id);

    /**
     * Generic method to insert an object.
     * @param object the object to insert
     * @return the persisted object
     */
    T insert(T object);
    
    /**
     * Generic method to update an object.
     * @param object the object to update
     * @return the persisted object
     */
    T update(T object);

    /**
     * Generic method to delete an object based on class and id
     * @param id the identifier (primary key) of the object to remove
     */
    void remove(PK id);
}